Pgm-Fi System — Acura MDX II рестайлинг (2010-2013)

Scheme 1

Scheme 1: Component Location Index

Scheme 2

DTC P0101: MAF Sensor Circuit Range/Performance Problem

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ). If DTC P1128, P1129, P2228, and/or P2229 are stored at the same time as DTC P0101, troubleshoot those DTCs first, then recheck for DTC P0101.

Check for poor connections or damage to these parts: PCV hose Intake air resonator Air cleaner Purge (PCS) line Brake booster Brake booster hose Are the parts OK? YES -Go to step 2. NO -Repair or replace the damaged part(s), then go to step 14 .
Check for a damaged or incorrectly installed air duct to the intake air cleaner. Is it OK? YES -Go to step 3. NO -Reconnect or replace the air duct, then go to step 14 .
Check for a dirty air cleaner element. Is it dirty? YES -Replace the air cleaner element (see «AIR CLEANER REMOVAL/INSTALLATION»(/acura/mdx/ii-2010-2013/remont/mechanical/#intake-air-system) ), then go to step 14 . NO -Go to step 4.
Turn the ignition switch to ON (II).
Check the MAF SENSOR in the DATA LIST with the HDS. Is there about 0.2 gm/s or 0.5 V? YES -Go to step 6. NO -Go to step 12 .
Start the engine.
Vary the engine speed between 2, 000 and 3, 000 rpm.
Check the MAF SENSOR in the DATA LIST with the HDS. Does the reading change? YES -Go to step 9. NO -Go to step 12 .
Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters: ENGINE SPEED VEHICLE SPEED MAP SENSOR MAF SENSOR
Monitor the OBD STATUS for DTC P0101 in the DTCs MENU with the HDS. Does the HDS indicate FAILED? YES -Go to step 12. NO -If the HDS indicates PASSED, intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the MAF sensor/IAT sensor and the PCM. If the HDS indicates NOT COMPLETED, go to step 10 and recheck.
Turn the ignition switch to LOCK (0).
Replace the MAF sensor/IAT sensor (see «MAF SENSOR/IAT SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ).
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters: ENGINE SPEED VEHICLE SPEED MAP SENSOR MAF SENSOR
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0101 indicated? YES -Check for poor connections or loose terminals at the MAF sensor/IAT sensor and the PCM, then go to step 1 . NO -Go to step 19.
Monitor the OBD STATUS for DTC P0101 in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 18 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the MAF sensor/IAT sensor and the PCM, then go to step 1 . If the HDS indicates NOT COMPLETED, go to step 17 .

DTC P0102: MAF Sensor Circuit Low Voltage

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 3

Scheme 3: DTC P0102: MAF Sensor Circuit Low Voltage

Scheme 4

Scheme 5

Scheme 6

Turn the ignition switch to ON (II), and wait 2 seconds.
Check the MAF SENSOR in the DATA LIST with the HDS. Is about 0 gm/s, or 0.1 V or less indicated? YES -Go to step 3. NO -Intermittent failure, the system is OK at this time. Check for poor connections, or loose terminals at the MAF sensor/IAT sensor and the PCM.
Turn the ignition switch to LOCK (0).
Disconnect the MAF sensor/IAT sensor 5P connector.
Turn the ignition switch to ON (II).
Measure the voltage between MAF sensor/IAT sensor 5P connector terminal No. 5 and body ground. Is there battery voltage? YES -Go to step 7. NO -Repair an open in the wire between the MAF sensor/IAT sensor and PGM-FI main relay 1, then go to step 19 .
Turn the ignition switch to LOCK (0).
Measure the resistance between MAF sensor/IAT sensor 5P connector terminal No. 3 and body ground. Is there 190-210 kohms? YES -Go to step 13 . NO -Go to step 9.
Jump the SCS line with the HDS.
Disconnect PCM connector A (49P).
Check for continuity between PCM connector terminal A20 and body ground. Is there continuity? YES -Repair a short in the wire between the PCM (A20) and the MAF sensor/IAT sensor, then go to step 20 . NO -Go to step 12.
Check for continuity between MAF sensor/IAT sensor 5P connector terminal No. 3 and PCM connector terminal A20. Is there continuity? YES -Go to step 25 . NO -Repair an open in the wire between the PCM (A20) and the MAF sensor/IAT sensor, then go to step 20 .
Substitute a known-good MAF sensor/IAT sensor (see «MAF SENSOR/IAT SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine. Hold the engine speed at 2, 000 rpm without load (in P or N).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0102 indicated? YES -Reinstall the original MAF sensor/IAT sensor, then go to step 25 . NO -Replace the original MAF sensor/IAT sensor (see «MAF SENSOR/IAT SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ), then go to step 19.
Turn the ignition switch to LOCK (0).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0102 indicated? YES -Check for poor connections or loose terminals at the MAF sensor/IAT sensor and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Reconnect all connectors, then update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0102 indicated? YES -Check for poor connections or loose terminals at the MAF sensor/IAT sensor and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P0103: MAF Sensor Circuit High Voltage

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 7

Scheme 7: DTC P0103: MAF Sensor Circuit High Voltage

Scheme 8

Turn the ignition switch to ON (II), and wait 2 seconds.
Check the MAF SENSOR in the DATA LIST with the HDS. Is about 202 gm/s, or 4.89 V or more indicated? YES -Go to step 3. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the MAF sensor/IAT sensor and the PCM.
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect the MAF sensor/IAT sensor 5P connector.
Disconnect PCM connector A (49P).
Check for continuity between MAF sensor/IAT sensor 5P connector terminal No. 4 and PCM connector terminal A9. Is there continuity? YES -Go to step 8. NO -Repair an open in the wire between the PCM (A9) and the MAF sensor/IAT sensor, then go to step 15 .
Reconnect PCM connector A (49P).
Connect MAF sensor/IAT sensor 5P connector terminals No. 3 and No. 4 with a jumper wire.
Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0103 indicated? YES -Go to step 20 . NO -Go to step 13.
Turn the ignition switch to LOCK (0).
Replace the MAF sensor/IAT sensor (see «MAF SENSOR/IAT SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0103 indicated? YES -Check for poor connections or loose terminals at the MAF sensor/IAT sensor and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Turn the ignition switch to LOCK (0).
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0103 indicated? YES -Check for poor connections or loose terminals at the MAF sensor/IAT sensor and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P0107: MAP Sensor Circuit Low Voltage

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 9

Scheme 9: DTC P0107: MAP Sensor Circuit Low Voltage

Scheme 10

Scheme 11

Turn the ignition switch to ON (II).
Check the MAP SENSOR in the DATA LIST with the HDS. Is about 3 kPa (1.0 inHg, 26 mmHg), or 0.23 V or less indicated? YES -Go to step 3. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the MAP sensor and the PCM.
Turn the ignition switch to LOCK (0).
Disconnect the MAP sensor 3P connector.
Turn the ignition switch to ON (II).
Check the MAP SENSOR in the DATA LIST with the HDS. Is about 3 kPa (1.0 inHg, 26 mmHg), or 0.23 V or less indicated? YES -Go to step 12 . NO -Go to step 7.
Measure the voltage between MAP sensor 3P connector terminals No. 1 and No. 3. Is there about 5 V? YES -Go to step 16 . NO -Go to step 8.
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connector B (49P).
Check for continuity between PCM connector terminal B36 and MAP sensor 3P connector terminal No. 1. Is there continuity? YES -Go to step 23 . NO -Repair an open in the wire between the PCM (B36) and the MAP sensor, then go to step 18 .
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connector B (49P).
Check for continuity between MAP sensor 3P connector terminal No. 2 and body ground. Is there continuity? YES -Repair a short in the wire between the PCM (B35) and the MAP sensor, then go to step 18 . NO -Go to step 23 .
Turn the ignition switch to LOCK (0).
Replace the MAP sensor (see «MAP SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0107 indicated? YES -Check for poor connections or loose terminals at the MAP sensor and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0107 indicated? YES -Check for poor connections or loose terminals at the MAP sensor and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P0108: MAP Sensor Circuit High Voltage

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 12

Scheme 12: DTC P0108: MAP Sensor Circuit High Voltage

Scheme 13

Scheme 14

Scheme 15

Turn the ignition switch to ON (II).
Check the MAP SENSOR in the DATA LIST with the HDS. Is about 160 kPa (47.1 inHg, 1, 197 mmHg), or 4.49 V or more indicated? YES -Go to step 3. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the MAP sensor and the PCM.
Turn the ignition switch to LOCK (0).
Disconnect the MAP sensor 3P connector.
Connect MAP sensor 3P connector terminals No. 2 and No. 3 with a jumper wire.
Turn the ignition switch to ON (II).
Check the MAP SENSOR in the DATA LIST with the HDS. Is about 160 kPa (47.1 inHg, 1, 197 mmHg), or 4.49 V or more indicated? YES -Go to step 8. NO -Go to step 20 .
Turn the ignition switch to LOCK (0).
Remove the jumper wire from the MAP sensor 3P connector.
Turn the ignition switch to ON (II).
Measure the voltage between MAP sensor 3P connector terminals No. 1 and No. 3. Is there about 5 V? YES -Go to step 16 . NO -Go to step 12.
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connector B (49P).
Check for continuity between PCM connector terminal B34 and MAP sensor 3P connector terminal No. 3. Is there continuity? YES -Go to step 27 . NO -Repair an open in the wire between the PCM (B34) and the MAP sensor, then go to step 22 .
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connector B (49P).
Check for continuity between PCM connector terminal B35 and MAP sensor 3P connector terminal No. 2. Is there continuity? YES -Go to step 27 . NO -Repair an open in the wire between the PCM (B35) and the MAP sensor, then go to step 22 .
Turn the ignition switch to LOCK (0).
Replace the MAP sensor (see «MAP SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0108 indicated? YES -Check for poor connections or loose terminals at the MAP sensor and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0108 indicated? YES -Check for poor connections or loose terminals at the MAP sensor and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P0111: IAT Sensor Circuit Range/Performance Problem

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Check for poor connections or loose terminals at ECT sensor 1, ECT sensor 2, and the MAF sensor/I AT sensor. Are the connections and terminals OK? YES -Go to step 2. NO -Repair the connections or terminals, then go to step 16 .
Remove the MAF sensor/IAT sensor (see «MAF SENSOR/IAT SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ).
Allow the MAF sensor/IAT sensor to cool to the ambient temperature.
Note the ambient temperature.
Set the HDS to the PGM-FI DATA LIST for IAT SENSOR.
Connect the MAF sensor/IAT sensor to its 5P connector, but do not install it.
Turn the ignition switch to ON (II).
Quickly note the value of the IAT SENSOR quickly in the DATA LIST with the HDS.
Compare the value of the IAT SENSOR to the ambient temperature. Does the value of the IAT SENSOR differ 5.4 °F (3 °C) or more from the ambient temperature? YES -Go to step 14 . NO -Go to step 10.
Disconnect the MAF sensor/IAT sensor from the 5P connector.
Using a heat gun, blow hot air on the MAF sensor/IAT sensor for a few seconds. Do not apply the heat longer than a few seconds or you will damage the sensor.
Connect the MAF sensor/IAT sensor to its 5P connector, but do not install it.
Check the IAT SENSOR in the DATA LIST with the HDS. Does the IAT SENSOR change 77 °F (43 °C) or more? YES -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the MAF sensor/IAT sensor and the PCM. NO -Go to step 14.
Turn the ignition switch to LOCK (0).
Replace the MAF sensor/IAT sensor (see «MAF SENSOR/IAT SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ).
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0111 indicated? YES -Check for poor connections or loose terminals at the MAF sensor/IAT sensor and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P0112: IAT Sensor Circuit Low Voltage

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 16

Scheme 16: DTC P0112: IAT Sensor Circuit Low Voltage

Turn the ignition switch to ON (II).
Check the IAT SENSOR in the DATA LIST with the HDS. Is about 356 °F (180 °C) or more, or 0.08 V or less indicated? YES -Go to step 3. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the MAF sensor/IAT sensor and the PCM.
Turn the ignition switch to LOCK (0).
Disconnect the MAF sensor/IAT sensor 5P connector.
Turn the ignition switch to ON (II).
Check the IAT SENSOR in the DATA LIST with the HDS. Is about 356 °F (180 °C) or more, or 0.08 V or less indicated? YES -Go to step 7. NO -Go to step 11 .
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connector C (49P).
Check for continuity between MAF sensor/IAT sensor 5P connector terminal No. 2 and body ground. Is there continuity? YES -Repair a short in the wire between the MAF sensor/IAT sensor and the PCM (C24), then go to step 13 . NO -Go to step 18 .
Turn the ignition switch to LOCK (0).
Replace the MAF sensor/IAT sensor (see «MAF SENSOR/IAT SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0112 indicated? YES -Check for poor connections or loose terminals at the MAF sensor/IAT sensor and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0112 indicated? YES -Check for poor connections or loose terminals at the MAF sensor/IAT sensor and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P0113: IAT Sensor Circuit High Voltage

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 17

Scheme 17: DTC P0113: IAT Sensor Circuit High Voltage

Scheme 18

Scheme 19

Scheme 20

Turn the ignition switch to ON (II).
Check the IAT SENSOR in the DATA LIST with the HDS. Is about -40 °F (-40 °C) or less, or 4.92 V or more indicated? YES -Go to step 3. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the MAF sensor/IAT sensor and the PCM.
Turn the ignition switch to LOCK (0).
Disconnect the MAF sensor/IAT sensor 5P connector.
Connect MAF sensor/IAT sensor 5P connector terminals No. 1 and No. 2 with a jumper wire.
Turn the ignition switch to ON (II).
Check the IAT SENSOR in the DATA LIST with the HDS. Is about -40 °F (-40 °C) or less, or 4.92 V or more indicated? YES -Go to step 8. NO -Go to step 20 .
Turn the ignition switch to LOCK (0).
Remove the jumper wire from the MAF sensor/IAT sensor 5P connector.
Turn the ignition switch to ON (II).
Measure the voltage between MAF sensor/IAT sensor 5P connector terminal No. 2 and body ground. Is there about 5 V? YES -Go to step 12. NO -Go to step 16 .
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connector C (49P).
Check for continuity between PCM connector terminal C16 and MAF sensor/IAT sensor 5P connector terminal No. 1. Is there continuity? YES -Go to step 27 . NO -Repair an open in the wire between the PCM (C16) and the MAF sensor/IAT sensor, then go to step 22 .
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connector C (49P).
Check for continuity between PCM connector terminal C24 and MAF sensor/IAT sensor 5P connector terminal No. 2. Is there continuity? YES -Go to step 27 . NO -Repair an open in the wire between the PCM (C24) and the MAF sensor/IAT sensor, then go to step 22 .
Turn the ignition switch to LOCK (0).
Replace the MAF sensor/IAT sensor (see «MAF SENSOR/IAT SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0113 indicated? YES -Check for poor connections or loose terminals at the MAF sensor/IAT sensor and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0113 indicated? YES -Check for poor connections or loose terminals at the MAF sensor/IAT sensor and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P0116: ECT Sensor 1 Circuit Range/Performance Problem

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Turn the ignition switch to ON (II).
Check ECT SENSOR 1 in the DATA LIST with the HDS. Is about 176 °F (80 °C) or more, or 0.78 V or less indicated? YES -Go to step 6 . NO -Go to step 3.
Note the value of ECT SENSOR 1 in the DATA LIST with the HDS.
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
Check ECT SENSOR 1 in the DATA LIST with the HDS. Does ECT SENSOR 1 change 18 °F (10 °C) or more? YES -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at ECT sensor 1 and the PCM. NO -Go to step 11 .
Note the value of ECT SENSOR 1 in the DATA LIST with the HDS.
Turn the ignition switch to LOCK (0).
Open the hood, and let the engine cool for 3 hours.
Turn the ignition switch to ON (II).
Check ECT SENSOR 1 in the DATA LIST with the HDS. Does ECT SENSOR 1 change 18 °F (10 °C) or more? YES -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at ECT sensor 1 and the PCM. NO -Go to step 11.
Turn the ignition switch to LOCK (0).
Replace ECT sensor 1 (see «ECT SENSOR 1 REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ).
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0116 indicated? YES -Check for poor connections or loose terminals at ECT sensor 1 and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P0117: ECT Sensor 1 Circuit Low Voltage

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 21

Scheme 21: DTC P0117: ECT Sensor 1 Circuit Low Voltage

Turn the ignition switch to ON (II).
Check ECT SENSOR 1 in the DATA LIST with the HDS. Is about 356 °F (180 °C) or more, or 0.08 V or less indicated? YES -Go to step 3. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at ECT sensor 1 and the PCM.
Turn the ignition switch to LOCK (0).
Disconnect the ECT sensor 1 2P connector.
Turn the ignition switch to ON (II).
Check ECT SENSOR 1 in the DATA LIST with the HDS. Is about 356 °F (180 °C) or more, or 0.08 V or less indicated? YES -Go to step 7. NO -Go to step 11 .
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connector C (49P).
Check for continuity between ECT sensor 1 2P connector terminal No. 1 and body ground. Is there continuity? YES -Repair a short in the wire between ECT sensor 1 and the PCM (C32), then go to step 13 . NO -Go to step 18 .
Turn the ignition switch to LOCK (0).
Replace ECT sensor 1 (see «ECT SENSOR 1 REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0117 indicated? YES -Check for poor connections or loose terminals at ECT sensor 1 and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0117 indicated? YES -Check for poor connections or loose terminals at ECT sensor 1 and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P0118: ECT Sensor 1 Circuit High Voltage

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 22

Scheme 22: DTC P0118: ECT Sensor 1 Circuit High Voltage

Scheme 23

Scheme 24

Scheme 25

Turn the ignition switch to ON (II).
Check ECT SENSOR 1 in the DATA LIST with the HDS. Is about -40 °F (-40 °C) or less, or 4.92 V or more indicated? YES -Go to step 3. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at ECT sensor 1 and the PCM.
Turn the ignition switch to LOCK (0).
Disconnect the ECT sensor 1 2P connector.
Connect ECT sensor 1 2P connector terminals No. 1 and No. 2 with a jumper wire.
Turn the ignition switch to ON (II).
Check ECT SENSOR 1 in the DATA LIST with the HDS. Is about -40 °F (-40 °C) or less, or 4.92 V or more indicated? YES -Go to step 8. NO -Go to step 20 .
Turn the ignition switch to LOCK (0).
Remove the jumper wire from the ECT sensor 1 2P connector.
Turn the ignition switch to ON (II).
Measure the voltage between ECT sensor 1 2P connector terminal No. 1 and body ground. Is there about 5 V? YES -Go to step 12. NO -Go to step 16 .
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connector C (49P).
Check for continuity between PCM connector terminal C16 and ECT sensor 1 2P connector terminal No. 2. Is there continuity? YES -Go to step 27 . NO -Repair an open in the wire between the PCM (C16) and ECT sensor 1, then go to step 22 .
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connector C (49P).
Check for continuity between PCM connector terminal C32 and ECT sensor 1 2P connector terminal No. 1. Is there continuity? YES -Go to step 27 . NO -Repair an open in the wire between the PCM (C32) and ECT sensor 1, then go to step 22 .
Turn the ignition switch to LOCK (0).
Replace ECT sensor 1 (see «ECT SENSOR 1 REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0118 indicated? YES -Check for poor connections or loose terminals at ECT sensor 1 and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0118 indicated? YES -Check for poor connections or loose terminals at ECT sensor 1 and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P0125: ECT Sensor 1 Malfunction/Slow Response

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Start the engine, and let it idle for 5 minutes or more.
Check ECT SENSOR 1 in the DATA LIST with the HDS. Is about 10°F (-12 °C) or less indicated? YES -Check for poor connections or loose terminals at ECT sensor 1, ECT sensor 2, and the PCM. If the connections and terminals are OK, replace ECT sensor 1 (see «ECT SENSOR 1 REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ), then go to step 7 . NO -Go to step 3.
Turn the ignition switch to LOCK (0).
Allow the engine to cool to 104 °F (40 °C) or less.
Start the engine, and let it idle until ECT SENSOR 1 reads about 158 °F (70 °C). Does ECT SENSOR 2 also read about 158 °F (70 °C)? YES -Go to step 6. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at ECT sensor 1, ECT sensor 2, and the PCM.
Check the thermostat (see «FAN MOTOR TEST»(/acura/mdx/ii-2010-2013/remont/cooling-fan/#engine-cooling-system) ). Is the thermostat OK? YES -Check for poor connections or loose terminals at ECT sensor 1, ECT sensor 2, and the PCM. If the connections and terminals are OK, replace ECT sensor 1 (see «ECT SENSOR 1 REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ), then go to step 7. NO -Replace the thermostat (see «THERMOSTAT REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/cooling-fan/#engine-cooling-system) ), then go to step 7.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Turn the ignition switch to LOCK (0).
Allow the engine to cool to 104 °F (40 °C) or less.
Start the engine, and let it idle until ECT SENSOR 1 reads about 158 °F (70 °C). Does ECT SENSOR 2 also show about 158 °F (70 °C)? YES -Go to step 1 and recheck. NO -Troubleshooting is complete.

DTC P0128: Cooling System Malfunction

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Make sure the blower switch is OFF.
Check the FAN HIGH CTRL and FAN LOW CTRL in the DATA LIST with the HDS. Is it OFF? YES -Go to step 5. NO -Wait until the FAN CTRL is off, then go to step 5.
Check the radiator fan operation. Does the radiator fan keep running? YES -Check the radiator fan high speed circuit (see «RADIATOR FAN HIGH SPEED CIRCUIT TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/cooling-fan/#fan-controls) ), and the radiator fan relay (see «POWER RELAY TEST»(/acura/mdx/ii-2010-2013/remont/body-electrical/#relays__power-relay-test) ). If the circuits and the relay are OK, go to step 19 . NO -Go to step 6.
Let the engine cool until the coolant temperature is 104°F (40°C) or less.
Note the value of ECT SENSOR 1 and ECT SENSOR 2 in the DATA LIST with the HDS.
Start the engine, and let it idle.
Let the engine idle until ECT SENSOR 1 goes up 34 °F (19 °C) or more from the recorded temperature.
Check ECT SENSOR 2 in the DATA LIST with the HDS.
Compare the recorded value of ECT SENSOR 2 and the present value of ECT SENSOR 2. Did the temperature rise 17 °F (9.5 °C) or more? YES -Test the thermostat (see «FAN MOTOR TEST»(/acura/mdx/ii-2010-2013/remont/cooling-fan/#engine-cooling-system) ), then go to step 12. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at ECT sensor 1, ECT sensor 2, and the PCM.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Let the engine cool until the coolant temperature is between 21 °F (-6 °C) and 104 °F (40 °C).
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Test-drive at a steady speed between 15-75 mph (24-120 km/h) for 30 minutes.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0128 indicated? YES -Check the cooling system, then go to step 19 . NO -Go to step 18.
Monitor the OBD STATUS for DTC P0128 in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 17 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check the cooling system, then go to step 19. If the HDS indicates NOT COMPLETED, go to step 14 .
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Let the engine cool until the coolant temperature is between 21 °F (-6 °C) and 104 °F (40 °C).
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
Test-drive at a steady speed between 15-75 mph (24-120 km/h) for 30 minutes.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0128 indicated? YES -Check for poor connections or loose terminals at ECT sensor 1, ECT sensor 2, and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 20 . If the PCM was substituted, go to step 1 . NO -Go to step 24.
Monitor the OBD STATUS for DTC P0128 in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs were indicated in step 23 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at ECT sensor 1, ECT sensor 2, and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 20 . If the PCM was substituted, go to step 1 . If the HDS indicates NOT COMPLETED, go to step 20 .

DTC P0133: Rear A/F Sensor (Bank 1, Sensor 1) Malfunction/Slow Response; DTC P0153: Front A/F Sensor (Bank 2, Sensor 1) Malfunction/Slow Response

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ). If DTC P0139 and/or P0159* is stored at the same time as DTC P0133 and/or P0153*, troubleshoot DTC P0139 and/or P0159* first, then recheck for DTC P0133 and/or P0153*. Information marked with an asterisk (*) applies to the front bank (Bank 2).

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
Test-drive under these conditions: Engine coolant temperature (ECT SENSOR 1) above 158°F (70°C) Transmission in D Engine speed between 1, 250-2, 200 rpm Drive the vehicle at 25 mph (40 km/h) or less for 5 minutes, then drive at a steady speed of 35 mph (57 km/h) or more
Monitor the OBD STATUS for DTC P0133 and/or P0153* in the DTCs MENU with the HDS. Does the HDS indicate FAILED? YES -Go to step 6. NO -If the HDS indicates PASSED, intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM. If the HDS indicates EXECUTING, keep driving until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 3 and recheck.
Turn the ignition switch to LOCK (0).
Replace the A/F sensor (Sensor 1) (see «A/F SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__af-sensor-replacement) ).
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
Test-drive under these conditions: Engine coolant temperature (ECT SENSOR 1) above 158°F (70°C) Transmission in D Engine speed between 1, 250-2, 200 rpm Drive the vehicle at 25 mph (40 km/h) or less for 5 minutes, then drive at a steady speed of 35 mph (57 km/h) or more
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0133 and/or P0153* indicated? YES -Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM, then go to step 1 . NO -Go to step 14.
Monitor the OBD STATUS for DTC P0133 and/or P0153* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 13 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM, then go to step 1 . If the HDS indicates EXECUTING, keep driving until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 11 .

DTC P0134: Rear A/F Sensor (Bank 1, Sensor 1) Heater System Malfunction; DTC P0154: Front A/F Sensor (Bank 2, Sensor 1) Heater System Malfunction

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ). If DTC P2251 and/or P2254* is stored at the same time as DTC P0134 and/or P0154*, troubleshoot DTC P2251 and/or P2254* first, then recheck for P0134 and/or P0154*. Information marked with an asterisk (*) applies to the front bank (Bank 2).

Scheme 26

Scheme 26: DTC P0134: Rear A/F Sensor (Bank 1, Sensor 1) Heater System Malfunction; DTC P0154: Front A/F Sensor

Scheme 27

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine, and let it idle without load (in P or N) for at least 1 minute.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0134 and/or P0154* indicated? YES -Go to step 5. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the A/F sensor (Sensor 1), the under-hood fuse/relay box (PGM-FI subrelay), and the PCM.
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect the A/F sensor (Sensor 1) 6P connector.
Disconnect PCM connector B (49P).
Check for continuity between A/F sensor (Sensor 1) 6P connector terminal No. 4 and PCM connector terminal B13(B14)*. Is there continuity? YES -Go to step 10. NO -Repair an open in the wire between the PCM (B13 (B14)*) and the A/F sensor (Sensor 1), then go to step 14 .
Reconnect PCM connector B (49P).
Start the engine, and let it idle without load (in P or N) for at least 1 minute.
Measure the voltage between A/F sensor (Sensor 1) 6P connector terminal No. 4 and body ground. Is there about 0.2 V or less? YES -Go to step 20 . NO -Go to step 13.
Replace the A/F sensor (Sensor 1) (see «A/F SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__af-sensor-replacement) ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0134 and/or P0154* indicated? YES -Check for poor connections or loose terminals at the A/F sensor (Sensor 1), the under-hood fuse/relay box (PGM-FI subrelay), and the PCM, then go to step 1 . NO -Go to step 19.
Monitor the OBD STATUS for DTC P0134 and/or P0154* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 18 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the A/F sensor (Sensor 1), the under-hood fuse/relay box (PGM-FI subrelay), and the PCM, then go to step 1 . If the HDS indicates NOT COMPLETED, keep idling until a result comes on.
Turn the ignition switch to LOCK (0).
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Start the engine, and let it idle without load (in P or N) for at least 1 minute.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0134 and/or P0154* indicated? YES -Check for poor connections or loose terminals at the A/F sensor (Sensor 1), the under-hood fuse/relay box (PGM-FI subrelay), and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 23 . If the PCM was substituted, go to step 1 . NO -Go to step 25.
Monitor the OBD STATUS for DTC P0134 and/or P0154* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs were indicated in step 24 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the A/F sensor (Sensor 1), the under-hood fuse/relay box (PGM-FI subrelay), and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 23 . If the PCM was substituted, go to step 1 . If the HDS indicates NOT COMPLETED, keep idling until a result comes on.

DTC P0135: Rear A/F Sensor (Bank 1, Sensor 1) Heater Circuit Malfunction; DTC P0155: Front A/F Sensor (Bank 2, Sensor 1) Heater Circuit Malfunction

Scheme 28

Scheme 28: DTC P0135: Rear A/F Sensor (Bank 1, Sensor 1) Heater Circuit Malfunction; DTC P0155: Front A/F Senso

Scheme 29

Scheme 30

Scheme 31

Scheme 32

Scheme 33

Scheme 34

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0135 and/or P0155* indicated? YES -Go to step 5. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the A/F sensor (Sensor 1), the under-hood fuse/relay box (PGM-FI subrelay), and the PCM.
Turn the ignition switch to LOCK (0).
Check No. 11 A/F sensor (AFHT+) (15 A) fuse in the under-hood fuse/relay box. Is the fuse OK? YES -Go to step 7. NO -Repair a short in the wire between the A/F sensors, the under-hood fuse/relay box (PGM-FI subrelay), then replace the blown fuse, and go to step 23 .
Disconnect the A/F sensor (Sensor 1) 6P connector.
At the sensor side, measure the resistance between A/F sensor (Sensor 1) 6P connector terminals No. 1 and No. 2. Is there 2.5-4.0 ohms at room temperature (65-70 °F, 18-21 °C)? YES -Go to step 9. NO -Go to step 21 .
At the sensor side, check for continuity between each terminal of at the A/F sensor (Sensor 1) 6P connector and body ground. Is there continuity to ground at any of the terminals? YES -Go to step 21 . NO -Go to step 10.
At the sensor side, check for continuity between A/F sensor (Sensor 1) 6P connector terminals No. 1 and each of the other terminals in the connector individually. Is there continuity? YES -Go to step 21 . NO -Go to step 11.
Jump the SCS line with the HDS.
Disconnect PCM connector C (49P).
Check for continuity between PCM connector terminal C6 (C8)* and body ground. Is there continuity? YES -Repair a short in the wire between the PCM (C6 (C8)*) and the A/F sensor (Sensor 1), then go to step 22 . NO -Go to step 14.
Check for continuity between A/F sensor (Sensor 1) 6P connector terminal No. 2 and PCM connector terminal C6 (C8)*. Is there continuity? YES -Go to step 15. NO -Repair an open in the wire between the PCM (C6 (C8)*) and the A/F sensor (Sensor 1), then go to step 22 .
Disconnect under-hood fuse/relay box connector H (9P).
Check for continuity between A/F sensor (Sensor 1) 6P connector terminal No. 1 and under-hood fuse/relay box connector H (9P) terminal No. 9. Is there continuity? YES -Go to step 17. NO -Repair an open in the wire between the A/F sensor (Sensor 1) and the under-hood fuse/relay box, then go to step 22 .
Disconnect PCM connector A (49P).
Disconnect under-hood fuse/relay box connector E (14P).
Check for continuity between under-hood fuse/relay box connector E (14P) terminal No. 13 and PCM connector terminal A40. Is there continuity? YES -Go to step 20. NO -Repair an open in the wire between the PCM (A40) and the under-hood fuse/relay box, then go to step 22 .
Test the PGM-FI subrelay (built into the relay control module) (see «RELAY CONTROL MODULE TEST»(/acura/mdx/ii-2010-2013/remont/body-electrical/#relays__relay-control-module-test) ). Is the PGM-FI subrelay OK? YES -Go to step 28 . NO -Replace the under-hood fuse/relay box (see «DTC B1065: RELAY CONTROL MODULE LOST COMMUNICATION WITH DRIVER'S MPCS UNIT (DRLOCKSW MESSAGE)»(/acura/mdx/ii-2010-2013/remont/fuses-circuit-breakers/#under-hood-fuserelay-box__dtc-b1065-relay-control-module-lost) ), then go to step 22 .
Replace the A/F sensor (Sensor 1) (see «A/F SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__af-sensor-replacement) ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0135 and/or P0155* indicated? YES -Check for poor connections or loose terminals at the A/F sensor (Sensor 1), the under-hood fuse/relay box (PGM-FI subrelay) and the PCM, then go to step 1 . NO -Go to step 27.
Monitor the OBD STATUS for DTC P0135 and/or P0155* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 26 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the A/F sensor (Sensor 1), the under-hood fuse/relay box (PGM-FI subrelay) and the PCM, then go to step 1 . If the HDS indicates NOT COMPLETED, keep idling until a result comes on.
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Start the engine, and let it idle.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0135 and/or P0155* indicated? YES -Check for poor connections or loose terminals at the A/F sensor (Sensor 1), the under-hood fuse/relay box (PGM-FI subrelay) and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 30 . If the PCM was substituted, go to step 1 . NO -Go to step 32.
Monitor the OBD STATUS for DTC P0135 and/or P0155* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs were indicated in step 31 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the A/F sensor (Sensor 1), the under-hood fuse/relay box (PGM-FI subrelay) and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 30 . If the PCM was substituted, go to step 1 . If the HDS indicates NOT COMPLETED, keep idling until a result comes on.

DTC P0137: Rear Secondary HO2S (Bank 1, Sensor 2) Circuit Low Voltage; DTC P0157: Front Secondary HO2S (Bank 2, Sensor 2) Circuit Low Voltage

Scheme 35

Scheme 35: DTC P0137: Rear Secondary HO2S (Bank 1, Sensor 2) Circuit Low Voltage; DTC P0157: Front Secondary HO

Scheme 36

Scheme 37

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
Monitor the OBD STATUS for DTC P0137 and/or P0157* in the DTCs MENU with the HDS. Does the HDS indicate FAILED? YES -Go to step 5. NO -If the HDS indicates PASSED, intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM. If the HDS indicates EXECUTING, keep driving until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 3 and recheck.
Turn the ignition switch to LOCK (0).
Disconnect the secondary HO2S (Sensor 2) 4P connector.
Connect secondary HO2S (Sensor 2) 4P connector terminals No. 1 and No. 2 with a jumper wire.
Turn the ignition switch to ON (II).
Check HO2S B1 S2 OUTPUT VOLTAGE and/or HO2S B2 S2 OUTPUT VOLTAGE* in the DATA LIST with the HDS. Does the voltage stay at 0.12 V or less? YES -Go to step 10. NO -Go to step 22 .
Turn the ignition switch to LOCK (0).
Remove the jumper wire from the secondary HO2S (Sensor 2) 4P connector.
Turn the ignition switch to ON (II).
Check HO2SB1 S2 OUTPUT VOLTAGE and/or HO2SB2 S2 OUTPUT VOLTAGE* in the DATA LIST with the HDS. Is there about 5 V? YES -Go to step 14. NO -Go to step 18 .
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connector C (49P).
Check for continuity between PCM connector terminal C23 (C36)* and body ground. Is there continuity? YES -Repair a short in the wire between the PCM (C23 (C36)*) and the secondary HO2S (Sensor 2), then go to step 24 . NO -Go to step 31 .
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connector B (49P).
Check for continuity between PCM connector terminal B25 (B16)* and body ground. Is there continuity? YES -Repair a short in the wire between the PCM (B25 (B16)*) and the secondary HO2S (Sensor 2), then go to step 24 . NO -Go to step 31 .
Turn the ignition switch to LOCK (0).
Replace the secondary HO2S (Sensor 2) (see «SECONDARY HO2S REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__secondary-ho2s-replacement) ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0137 and/or P0157* indicated? YES -Check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM, then go to step 1 . NO -Go to step 30.
Monitor the OBD STATUS for DTC P0137 and/or P0157* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs were indicated in step 29 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 28 . If the PCM was substituted, go to step 1 . If the HDS indicates EXECUTING, keep driving until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 28 .
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0137 and/or P0157* indicated? YES -Check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM. If the PCM was updated, substitute a know-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 33 . If the PCM was substituted, go to step 1 . NO -Go to step 35.
Monitor the OBD STATUS for DTC P0137 and/or P0157* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs were indicated in step 34 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 33 . If the PCM was substituted, go to step 1 . If the HDS indicates EXECUTING, keep driving until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 33 .

DTC P0138: Rear Secondary HO2S (Bank 1, Sensor 2) Circuit High Voltage; DTC P0158: Front Secondary HO2S (Bank 2, Sensor 2) Circuit High Voltage

Scheme 38

Scheme 38: DTC P0138: Rear Secondary HO2S (Bank 1, Sensor 2) Circuit High Voltage; DTC P0158: Front Secondary H

Scheme 39

Scheme 40

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine, and let it idle without load (in P or N) until the radiator fan comes on, then let it idle.
Check HO2S B1 S2 OUTPUT VOLTAGE and/or HO2S B2 S2 OUTPUT VOLTAGE* in the DATA LIST with the HDS. Does the voltage stay at 1.27 V or more? YES -Go to step 5. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM.
Turn the ignition switch to LOCK (0).
Disconnect the secondary HO2S (Sensor 2) 4P connector.
Connect secondary HO2S (Sensor 2) 4P connector terminals No. 1 and No. 2 with a jumper wire.
Turn the ignition switch to ON (II).
Check HO2S B1 S2 OUTPUT VOLTAGE and/or HO2S B2 S2 OUTPUT VOLTAGE* in the DATA LIST with the HDS. Does the voltage stay at 1.27 V or more? YES -Go to step 10. NO -Go to step 19 .
Turn the ignition switch to LOCK (0).
Remove the jumper wire from the secondary HO2S (Sensor 2) 4P connector.
Connect secondary HO2S (Sensor 2) 4P connector terminal No. 1 to body ground with a jumper wire.
Turn the ignition switch to ON (II).
Check HO2S B1 S2 OUTPUT VOLTAGE and/or HO2S B2 S2 OUTPUT VOLTAGE* in the DATA LIST with the HDS. Does the voltage stay at 1.27 V or more? YES -Go to step 15. NO -Repair an open in the wire between the PCM (C23 (C36)*) and the secondary HO2S (Sensor 2), then go to step 21 .
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connector B (49P).
Check for continuity between PCM connector terminal B25 (B16)* and body ground. Is there continuity? YES -Go to step 29 . NO -Repair an open in the wire between the PCM (B25 (B16)*) and the secondary HO2S (Sensor 2), then go to step 21 .
Turn the ignition switch to LOCK (0).
Replace the secondary HO2S (Sensor 2) (see «SECONDARY HO2S REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__secondary-ho2s-replacement) ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Start the engine, and let it idle without load (in P or N) until the radiator fan comes on.
Test-drive under these conditions: Engine coolant temperature (ECT SENSOR 1) above 158°F (70°C) Transmission in D Engine speed between 1, 500-3, 000 rpm Drive 5 seconds or more
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0138 and/or P0158* indicated? YES -Check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM, then go to step 1 . NO -Go to step 28.
Monitor the OBD STATUS for DTC P0138 and/or P0158* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 27 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM, then go to step 1 . If the HDS indicates EXECUTING, keep driving until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 25 .
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Start the engine, and let it idle without load (in P or N) until the radiator fan comes on.
Test-drive under these conditions: Engine coolant temperature (ECT SENSOR 1) above 158°F (70°C) Transmission in D Engine speed between 1, 500-3, 000 rpm Drive 5 seconds or more
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0138 and/or P0158* indicated? YES -Check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 31 . If the PCM was substituted, go to step 1 . NO -Go to step 34.
Monitor the OBD STATUS for DTC P0138 and/or P0158* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs were indicated in step 33 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 31 . If the PCM was substituted, go to step 1 . If the HDS indicates EXECUTING, keep driving until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 31 .

DTC P0139: Rear Secondary HO2S (Bank 1, Sensor 2) Slow Response; DTC P0159: Front Secondary HO2S (Bank 2, Sensor 2) Slow Response

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine, and let it idle without load (in P or N) until the radiator fan comes on.
Test-drive under these conditions: Engine coolant temperature (ECT SENSOR 1) above 158°F (70°C) Transmission in D Drive at a steady speed between 55-75 mph (88-120 km/h)for 1 minute, then decelerate (with the throttle fully closed) for 10 seconds
Monitor the OBD STATUS for DTC P0139 and/or P0159* in the DTCs MENU with the HDS. Does the HDS indicate FAILED? YES -Go to step 6. NO -If the HDS indicates PASSED, intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at secondary HO2S (Sensor 2) and the PCM. If the HDS indicates EXECUTING, keep driving until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 3 and recheck.
Turn the ignition switch to LOCK (0).
Replace the secondary HO2S (Sensor 2) (see «SECONDARY HO2S REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__secondary-ho2s-replacement) ).
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Start the engine, and let it idle without load (in P or N) until the radiator fan comes on.
Test-drive under these conditions: Engine coolant temperature above 158 °F (70 °C) Transmission in D Drive at a steady speed between 55-75 mph (88-120 km/h)for 1 minute, then decelerate (with the throttle fully closed) for 10 seconds
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0139 and/or P0159* indicated? YES -Check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM, then go to step 1 . NO -Go to step 14.
Monitor the OBD STATUS for DTC P0139 and/or P0159* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 13 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM, then go to step 1 . If the HDS indicates EXECUTING, keep driving until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 11 .

DTC P0141: Rear Secondary HO2S (Bank 1, Sensor 2) Heater Circuit Malfunction; DTC P0161: Front Secondary HO2S (Bank 2, Sensor 2) Heater Circuit Malfunction

Scheme 41

Scheme 41: DTC P0141: Rear Secondary HO2S (Bank 1, Sensor 2) Heater Circuit Malfunction; DTC P0161: Front Secon

Scheme 42

Scheme 43

Scheme 44

Scheme 45

Scheme 46

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0141 and/or P0161* indicated? YES -Go to step 5. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the secondary HO2S (Sensor 2), the under-hood fuse/relay box (PGM-FI subrelay) and the PCM.
Turn the ignition switch to LOCK (0).
Check No. 11 A/F sensor (AFHT+) (15 A) fuse in the under-hood fuse/relay box. Is the fuse OK? YES -Go to step 7. NO -Repair a short in the wire between the A/F sensors, the under-hood fuse/relay box (PGM-FI subrelay), then replace the blown fuse, then go to step 21 .
Disconnect the secondary HO2S (Sensor 2) 4P connector.
At the sensor side, measure the resistance between secondary HO2S (Sensor 2) 4P connector terminals No. 3 and No. 4. Is there 5.4-6.6 ohms at room temperature (65-70 °F, 18-21 °C)? YES -Go to step 9. NO -Go to step 20 .
At the sensor side, check for continuity between body ground and secondary HO2S (Sensor 2) 4P connector terminals No. 3 and No. 4 individually. Is there continuity? YES -Go to step 20 . NO -Go to step 10.
Jump the SCS line with the HDS.
Disconnect PCM connector C (49P).
Check for continuity between PCM connector terminal C5 (C7)* and body ground. Is there continuity? YES -Repair a short in the wire between the PCM (C5 (C7)*) and the secondary HO2S (Sensor 2), then go to step 21 . NO -Go to step 13.
Check for continuity between secondary HO2S (Sensor 2) 4P connector terminal No. 3 and PCM connector terminal C5 (C7)*. Is there continuity? YES -Go to step 14. NO -Repair an open in the wire between the PCM (C5 (C7)*) and the secondary HO2S (Sensor 2), then go to step 21 .
Disconnect under-hood fuse/relay box connector H OP).
Check for continuity between secondary HO2S (Sensor 2) 4P connector terminal No. 4 and under-hood fuse/relay box connector H (9P) terminal No. 9. Is there continuity? YES -Go to step 16. NO -Repair an open in the wire between the secondary HO2S (Sensor 2) and the under-hood fuse/relay box, then go to step 21 .
Disconnect PCM connector A (49P).
Disconnect under-hood fuse/relay box connector E (14P).
Check for continuity between under-hood fuse/relay box connector E (14P) terminal No. 13 and PCM connector terminal A40. Is there continuity? YES -Go to step 19. NO -Repair an open in the wire between the PCM (A40) and the under-hood fuse/relay box, then go to step 21 .
Test the PGM-FI subrelay (built into the relay control module) (see «RELAY CONTROL MODULE TEST»(/acura/mdx/ii-2010-2013/remont/body-electrical/#relays__relay-control-module-test) ). Is the PGM-FI subrelay OK? YES -Go to step 27 . NO -Replace the under-hood fuse/relay box (see «DTC B1065: RELAY CONTROL MODULE LOST COMMUNICATION WITH DRIVER'S MPCS UNIT (DRLOCKSW MESSAGE)»(/acura/mdx/ii-2010-2013/remont/fuses-circuit-breakers/#under-hood-fuserelay-box__dtc-b1065-relay-control-module-lost) ), then go to step 21 .
Replace the secondary HO2S (Sensor 2) (see «SECONDARY HO2S REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__secondary-ho2s-replacement) ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0141 and/or P0161* indicated? YES -Check for poor connections or loose terminals at the secondary HO2S (Sensor 2), the under-hood fuse/relay box (PGM-FI subrelay), and the PCM, then go to step 1 . NO -Go to step 26.
Monitor the OBD STATUS for DTC P0141 and/or P0161* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 25 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the secondary HO2S (Sensor 2), the under-hood fuse/relay box (PGM-FI subrelay), and the PCM, then go to step 1 . If the HDS indicates NOT COMPLETED, keep idling until a result comes on.
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Start the engine, and let it idle.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0141 and/or P0161* indicated? YES -Check for poor connections or loose terminals at the secondary HO2S (Sensor 2), the under-hood fuse/relay box (PGM-FI subrelay), and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 29 . If the PCM was substituted, go to step 1 . NO -Go to step 31.
Monitor the OBD STATUS for DTC P0141 and/or P0161* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs were indicated in step 30 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the secondary HO2S (Sensor 2), the under-hood fuse/relay box (PGM-FI subrelay), and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 29 . If the PCM was substituted, go to step 1 . If the HDS indicates NOT COMPLETED, keep idling until a result comes on.

DTC P0171: Rear Bank (Bank 1) Fuel System Too Lean; DTC P0172: Rear Bank (Bank 1) Fuel System Too Rich; DTC P0174: Front Bank (Bank 2) Fuel System Too Lean; DTC P0175: Front Bank (Bank 2) Fuel System Too Rich

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ). Poor fuel quality can cause DTC P0171, P0174. If some of the DTCs listed below are stored at the same time as DTC P0171, P0172, P0174, and/or P0175, troubleshoot those DTCs first, then recheck for P0171, P0172, P0174, and/or P0175. P0101, P0102, P0103: MAF sensor P0107, P0108, P1128, P1129: MAP sensor P0133, P0153, P1172, P1174, P2195, P2197, P2237, P2238, P2240, P2241, P2243, P2245, P2247, P2249, P2251, P2252, P2254, P2255, P2A00, P2A03: A/F sensor (Sensor 1) P0134, P0135, P0154, P0155: A/F sensor (Sensor 1) heater P0137, P0138, P0139, P0157, P0158, P0159, P2270, P2272: Secondary HO2S(Sensor 2) P0141, P0161: Secondary HO2S (Sensor 2) heater P2646, P2647, P2648, P2649: VTEC system P0401, P0404, P0406, P2413: EGR system P2279: Intake air leakage

Check the fuel pressure (see «FUEL PRESSURE TEST»(/acura/mdx/ii-2010-2013/remont/fuel-system/#fuel-supply-system__fuel-pressure-test) ). Is the fuel pressure OK? YES -Go to step 2. NO -Check these items: If the pressure is too high, replace the fuel pressure regulator (see «FUEL PRESSURE REGULATOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/fuel-system/#fuel-supply-system) ), then go to step 6 . If the pressure is too low, check for restrictions in the fuel pump, the fuel pressure regulator, the fuel filter, and the fuel lines for restrictions, then go to step 6 .
Check for vacuum leaks at these parts: PCV valve PCV hose EVAP canister purge valve Throttle body intake manifold Brake booster Brake booster hose Air intake duct Are the parts OK? YES -Go to step 3. NO -Repair or replace parts with leaks, go to step 6 .
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
Check for these conditions: Engine coolant temperature (ECT SENSOR 1) above 158°F (70°C) Transmission in P or N All electrical loads off
Monitor the ENGINE SPEED in the DATA LIST with the HDS. Raise and hold the engine speed steady at 2, 500 rpm. While holding the rpm steady, check the MAF SENSOR in the DATA LIST. Is there about 9.8-11.9 gm/s? YES -Replace the injectors (see «INJECTOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ), then go to step 6. NO -Replace the MAF sensor/IAT sensor (see «MAF SENSOR/IAT SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ), then go to step 6.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
Test-drive under these conditions: Engine coolant temperature (ECT SENSOR 1) above 158°F(70°C) Transmission in D Drive at a steady speed between 15-75 mph (24-120 km/h)for 15 minutes. NOTE: DTC P0171, P0172, P0174 and/or P0175 may take up to 80 minutes of test driving to set. Using the HDS, monitor the short term fuel trim (ST FUEL TRIM). If the ST FUEL TRIM stays within 0.8-1.21, there is no problem at this time.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0171, P0172, P0174 and/or P0175 indicated? YES -Go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P0300: Random Misfire and Any Combination of the Following:; DTC P0301: No. 1 Cylinder Misfire Detected; DTC P0302: No. 2 Cylinder Misfire Detected; DTC P0303: No. 3 Cylinder Misfire Detected; DTC P0304: No. 4 Cylinder Misfire Detected; DTC P0305: No. 5 Cylinder Misfire Detected; DTC P0306: No. 6 Cylinder Misfire Detected

Special Tools Required

Pressure Gauge Adapter 07NAJ-P07010A
A/T Low Pressure Gauge W/Panel 07406-0070301
AT Pressure Test Hose 07AAJ-PY4A100
A/T Pressure Adapter 07MAJ-PY40120
Oil Pressure Hose 07ZAJ-S5A0200

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ). If the misfire is frequent enough to trigger detection of increased emissions during two consecutive driving cycles, the MIL will come on, and DTC P0300 (and some combination of P0301 through P0306) are stored. If the misfire is frequent enough to damage the catalyst, the MIL will blink whenever the misfire occurs, and DTC P0300 (and some combination of P0301 through P0306) are stored. When the misfire stops, the MIL stays on. Troubleshoot the following DTCs first, if any of them were stored along with the random misfire DTC(s) (Because parts can sometimes fail without setting DTCs, you should also do a physical inspection of the system listed below.): P0101, P0102, P0103: MAF sensor P0107, P0108, P1128, P1129: MAP sensor P0171, P0172, P0174, P0175: Fuel system P0335, P0339: CKP sensor P0506, P0507: Idle control system P0365, P0369: CMP sensor P2646, P2647, P2648, P2649: VTEC system P0401, P0404, P0406, P2413: EGR system

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine, and let it idle without load (in P or N).
Monitor the OBD STATUS for DTC P0301, P0302, P0303, P0304, P0305, or P0306 in the DTCs MENU with the HDS. Does the HDS indicate FAILED? YES -Go to step 9 . NO -If the HDS indicates PASSED, go to step 5. If the HDS indicates EXECUTING, keep idle until a result comes on. If the HDS indicates OUT OF CONDITION, wait for several minutes, then recheck.
Check the CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE in the DATA LIST for 10 minutes with the HDS. Does CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE show misfire counts? YES -Go to step 9 . NO -Go to step 6.
Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters: ENGINE SPEED VEHICLE SPEED REL TP SENSOR CLV (calculated load value) ECT SENSOR 1 APP SENSOR
Monitor the OBD STATUS for DTC P0301, P0302, P0303, P0304, P0305, or P0306 in the DTCs MENU with the HDS. Does the HDS indicate FAILED? YES -Go to step 9 . NO -If the HDS indicates PASSED, go to step 8. If the HDS indicates EXECUTING, keep driving until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 6 and recheck.
Check the CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE in the DATA LIST for 10 minutes with the HDS. Does CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE show misfire counts? YES -Go to step 9. NO -Intermittent failure, the system is OK at this time.
Turn the ignition switch to LOCK (0).
Check the fuel quality. Is the fuel quality good? YES -Go to step 11. NO -Drain the fuel tank, and fill it with a known-good fuel, then go to step 19 .
Remove and inspect the spark plugs (see «IGNITION COIL AND SPARK PLUG REMOVAL/INSTALLATION»(/acura/mdx/ii-2010-2013/remont/ignition-system/#ignition-system) ). If the spark plugs are fouled or worn, replace them.
Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters: ENGINE SPEED VEHICLE SPEED REL TP SENSOR CLV (calculated load value) ECT SENSOR 1 APP SENSOR
Check the CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE in the DATA LIST for 10 minutes with the HDS. Does CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE show misfire counts? YES -Go to step 14. NO -Go to step 19 .
Check the fuel pressure (see «FUEL PRESSURE TEST»(/acura/mdx/ii-2010-2013/remont/fuel-system/#fuel-supply-system__fuel-pressure-test) ). Is the fuel pressure OK? YES -Go to step 15. NO - If the pressure is too high, replace the fuel pressure regulator (see «FUEL PRESSURE REGULATOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/fuel-system/#fuel-supply-system) ), then go to step 19 . If the pressure is too low, check for restrictions in the fuel pump, the fuel feed lines, and the fuel filter. If they are OK, replace the fuel pressure regulator (see «FUEL PRESSURE REGULATOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/fuel-system/#fuel-supply-system) ), then go to step 19 .
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
Check for these conditions: Engine coolant temperature (ECT SENSOR 1) above 176°F (80°C) Transmission in P or N All electrical loads off
Monitor the ENGINE SPEED in the DATA LIST with the HDS. Raise and hold the engine speed steady at 2, 500±100 rpm. While holding the rpm steady, check the MAF SENSOR in the DATA LIST. Is there about 9.8-11.9 gm/s? YES -Go to step 18. NO -Replace the MAF sensor/IAT sensor (see «MAF SENSOR/IAT SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ), then go to step 19 .
Do the VTEC rocker arm test (see «VTEC ROCKER ARM TEST»(/acura/mdx/ii-2010-2013/remont/mechanical/#cylinder-head__vtec-rocker-arm-test) ). Did the engine pass the test? YES -Go to step 20 . NO -Repair the VTEC rocker arm, then go to step 20 .
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Do the CKP pattern clear/CKP pattern learn procedure (see «HDS CLEAR COMMAND»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__hds-clear-command) ).
Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters: ENGINE SPEED VEHICLE SPEED REL TP SENSOR CLV (calculated load value) ECT SENSOR 1 APP SENSOR
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0300 and any combination of DTC P0301, P0302, P0303, P0304, P0305, or P0306 indicated? YES -Check for poor connections or loose terminals at the ignition coils, the injectors, and the PCM, then go to «DTC P0301, P0302, P0303, P0304, P0305, OR P0306 TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__dtc-p0301-no-1-cylinder-misfire) (see «DTC Troubleshooting»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ). NO -Go to step 25.
Monitor the OBD STATUS for DTC P0301, P0302, P0303, P0304, P0305, or P0306 in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 24 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the ignitions coils, the injectors, and the PCM, then go to step 1 . If the HDS indicates EXECUTING, keep driving until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 23 .

DTC P0301: No. 1 Cylinder Misfire Detected; DTC P0302: No. 2 Cylinder Misfire Detected; DTC P0303: No. 3 Cylinder Misfire Detected; DTC P0304: No. 4 Cylinder Misfire Detected; DTC P0305: No. 5 Cylinder Misfire Detected; DTC P0306: No. 6 Cylinder Misfire Detected

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 47

Scheme 47: DTC P0301: No. 1 Cylinder Misfire Detected; DTC P0302: No. 2 Cylinder Misfire Detected; DTC P0303: N

Scheme 48

Scheme 49

Scheme 50

Scheme 51

Scheme 52

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine, and let it idle without load (in P or N) for 2 minutes.
Monitor the OBD STATUS for DTC P0301, P0302, P0303, P0304, P0305, or P0306 in the DTCs MENU with the HDS. Does the HDS indicate FAILED? YES -Go to step 9 . NO -If the HDS indicates PASSED, go to step 5. If the HDS indicates EXECUTING, keep idling until a result comes on. If the HDS indicates OUT OF CONDITION, wait for several minutes, then recheck.
Check the CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE in the DATA LIST for 10 minutes with the HDS. Does CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE show misfire counts? YES -Go to step 9 . NO -Go to step 6.
Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters: ENGINE SPEED VEHICLE SPEED REL TP SENSOR CLV (calculated load value) GEAR POSITION ECT SENSOR 1
Monitor the OBD STATUS for DTC P0301, P0302, P0303, P0304, P0305, or P0306 in the DTCs MENU with the HDS. Does the HDS indicate FAILED? YES -Go to step 9 . NO -If the HDS indicates PASSED, go to step 8. If the HDS indicates EXECUTING, keep driving until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 6 .
Check the CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE in the DATA LIST for 10 minutes with the HDS. Does CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE show misfire counts? YES -Go to step 9. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals in the fuel system and the ignition system.
Turn the ignition switch to LOCK (0).
Exchange the ignition coil from the problem cylinder with one from another cylinder.
Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters: ENGINE SPEED VEHICLE SPEED REL TP SENSOR CLV (calculated load value) GEAR POSITION ECT SENSOR 1
Check the CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE in the DATA LIST for 10 minutes with the HDS. Does CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE show misfire counts? YES -Go to step 13. NO -Intermittent failure due to poor contact at an ignition coil contactor (no misfire at this time). Make sure that the ignition coil connectors are secure.
Determine which cylinder had the misfire. Does the misfire occur in the cylinder where the ignition coil was moved? YES -Replace the faulty ignition coil (see «IGNITION COIL AND SPARK PLUG REMOVAL/INSTALLATION»(/acura/mdx/ii-2010-2013/remont/ignition-system/#ignition-system) ), then go to step 44 . NO -Go to step 14.
Turn the ignition switch to LOCK (0).
Exchange the spark plugs from the problem cylinder with one from another cylinder.
Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters: ENGINE SPEED VEHICLE SPEED REL TP SENSOR CLV (calculated load value) GEAR POSITION ECT SENSOR 1
Check the CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE in the DATA LIST for 10 minutes with the HDS. Does CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE show misfire counts? YES -Go to step 18. NO -Intermittent failure due to spark plug fouling (no misfire at this time).
Determine which cylinder had the misfire. Does the misfire occur in the cylinder where the spark plugs were moved? YES -Replace the faulty spark plugs (see «IGNITION COIL AND SPARK PLUG REMOVAL/INSTALLATION»(/acura/mdx/ii-2010-2013/remont/ignition-system/#ignition-system) ), then go to step 45 . NO -Go to step 19.
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connector B (49P).
Remove the intake manifold (see «INTAKE MANIFOLD REMOVAL AND INSTALLATION»(/acura/mdx/ii-2010-2013/remont/mechanical/#intake-manifold-and-exhaust-system) ).
Turn the ignition switch to ON (II).
Measure the voltage between body ground and the appropriate PCM connector terminal (see table). PROBLEM CYLINDER DTC PCM TERMINAL WIRE COLOR No. 1 P0301 B4 BRN No. 2 P0302 B8 RED No. 3 P0303 B7 BLU No. 4 P0304 B6 YEL No. 5 P0305 B5 BLK/RED No. 6 P0306 B9 WHT/BLU Is there battery voltage? YES -Go to step 32 . NO -Go to step 25.
Turn the ignition switch to LOCK (0).
Disconnect the injector 2P connector from the problem cylinder.
Turn the ignition switch to ON (II).
Measure the voltage between injector 2P connector terminal No. 1 and body ground. Is there battery voltage? YES -Go to step 29. NO -Repair an open in the wire between the injector and the under-hood fuse/relay box (PGM-FI main relay 1), then go to step 44 .
Turn the ignition switch to LOCK (0).
Check for continuity between body ground and the appropriate PCM connector terminal (see table). PROBLEM CYLINDER DTC PCM TERMINAL WIRE COLOR No. 1 P0301 B4 BRN No. 2 P0302 B8 RED No. 3 P0303 B7 BLU No. 4 P0304 B6 YEL No. 5 P0305 B5 BLK/RED No. 6 P0306 B9 WHT/BLU Is there continuity? YES -Repair a short in the wire between the PCM and the injector, then go to step 44 . NO -Go to step 31.
Check for continuity between appropriate injector 2P connector terminal No. 2 and the PCM connector terminal of the problem cylinder (see table). PROBLEM CYLINDER DTC PCM TERMINAL WIRE COLOR No. 1 P0301 B4 BRN No. 2 P0302 B8 RED No. 3 P0303 B7 BLU No. 4 P0304 B6 YEL No. 5 P0305 B5 BLK/RED No. 6 P0306 B9 WHT/BLU Is there continuity? YES -Check for poor connections or loose terminals at the injector and the under-hood fuse/relay box (PGM-FI main relay 1), then go to step 32. NO -Repair an open in the wire between the PCM and the injector, then go to step 44 .
At the injector side, measure the resistance between injector 2P connector terminals No. 1 and No. 2. Is there 10.8-13.2 ohms? YES -Go to step 33. NO -Replace the injector (see «INJECTOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ), then go to step 44 .
Exchange the injector from the problem cylinder with the one from another cylinder. Also check the injector fuel inlet screen for debris, and clean it if needed.
Reconnect all connectors, and reinstall the intake manifold (see «INTAKE MANIFOLD REMOVAL AND INSTALLATION»(/acura/mdx/ii-2010-2013/remont/mechanical/#intake-manifold-and-exhaust-system) ).
Turn the ignition switch to ON (II).
Clear the DTCs with the HDS.
Start the engine, and let it idle without load (in P or N) for 2 minutes.
Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters: ENGINE SPEED VEHICLE SPEED REL TP SENSOR CLV (calculated load value) GEAR POSITION ECT SENSOR 1
Check the CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE in the DATA LIST for 10 minutes with the HDS. Does CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, CYL4 MISFIRE, CYL5 MISFIRE, and/or CYL6 MISFIRE show misfire counts? YES -Go to step 40. NO -Intermittent failure due to poor contact in the injector connector (no misfire at this time). Check for poor connections or loose terminals at the injector.
Determine which cylinder had the misfire. Does the misfire occur in the cylinder where the injector was moved? YES -Replace the faulty injector (see «INJECTOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ), then go to step 44 . NO -Go to step 41.
Turn the ignition switch to LOCK (0).
Do an engine compression and a cylinder leakdown test (see «ENGINE COMPRESSION INSPECTION»(/acura/mdx/ii-2010-2013/remont/mechanical/#cylinder-head__engine-compression-inspection) ). Did the engine pass both tests? YES -Go to step 43. NO -Repair the engine, then go to step 44 .
Do the VTEC rocker arm test (see «VTEC ROCKER ARM TEST»(/acura/mdx/ii-2010-2013/remont/mechanical/#cylinder-head__vtec-rocker-arm-test) ). Did the engine pass the test? YES -Go to step 52 . NO -Repair the VTEC rocker arm, then go to step 44.
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Do the CKP pattern clear/CKP pattern learn procedure (see «HDS CLEAR COMMAND»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__hds-clear-command) ).
Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters: ENGINE SPEED VEHICLE SPEED REL TP SENSOR CLV (calculated load value) GEAR POSITION ECT SENSOR 1
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0301, P0302, P0303, P0304, P0305, or P0306 indicated? YES -Check for poor connections or loose terminals at the ignition coils, the injectors, and the PCM, then go to the troubleshooting for DTC P0300, P0301, P0302, P0303, P0304, P0305, or P0306 (see «DTC P0300: RANDOM MISFIRE AND ANY COMBINATION OF THE FOLLOWING:; DTC P0301: NO. 1 CYLINDER MISFIRE DETECTED; DTC P0302: NO. 2 CYLINDER MISFIRE DETECTED; DTC P0303: NO. 3 CYLINDER MISFIRE DETECTED; DTC P0304: NO. 4 CYLINDER MISFIRE DETECTED; DTC P0305: NO. 5 CYLINDER MISFIRE DETECTED; DTC P0306: NO. 6 CYLINDER MISFIRE DETECTED»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__dtc-p0300-random-misfire-and-any) ). NO -Go to step 51.
Monitor the OBD STATUS for DTC P0301, P0302, P0303, P0304, P0305, or P0306 in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 50 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the ignition coils, the injectors, and the PCM, then go to step 1 . If the HDS indicates EXECUTING, keep driving until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 49 .
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters: ENGINE SPEED VEHICLE SPEED REL TP SENSOR CLV (calculated load value) GEAR POSITION ECT SENSOR 1
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0301, P0302, P0303, P0304, P0305, or P0306 indicated? YES -Check for poor connections or loose terminals at the ignition coils, the injectors, and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 54 . If the PCM was substituted, go to step 1 . NO -Go to step 56.
Monitor the OBD STATUS for DTC P0301, P0302, P0303, P0304, P0305, or P0306 in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs were indicated in step 55 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the ignition coils, the injectors, and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 54 . If the PCM was substituted, go to step 1 . If the HDS indicates EXECUTING, keep driving until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 54 .

DTC P0325: Knock Sensor Circuit Malfunction

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 53

Scheme 53: DTC P0325: Knock Sensor Circuit Malfunction

Scheme 54

Scheme 55

Scheme 56

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
Hold the engine speed at 3, 000-4, 000 rpm for at least 10 seconds.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0325 indicated? YES -Go to step 6. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the knock sensor and the PCM.
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect the knock sensor subharness (engine wire harness side) 1P connector.
Disconnect PCM connector C (49P).
Check for continuity between PCM connector terminal C47 and body ground. Is there continuity? YES -Repair a short in the wire between the PCM (C47) and the knock sensor subharness, then go to step 20 . NO -Go to step 11.
Connect the engine wire harness C152 1P connector terminal to body ground with a jumper wire.
Check for continuity between PCM connector terminal C47 and body ground. Is there continuity? YES -Go to step 13. NO -Repair an open in the wire between the PCM (C47) and the engine wire harness (C152 connector), then go to step 20 .
Remove the jumper wire from the engine wire harness.
Remove the intake manifold (see «REMOVAL»(/acura/mdx/ii-2010-2013/remont/mechanical/#intake-manifold-and-exhaust-system) ), and the injector base (see «INJECTOR BASE REMOVAL AND INSTALLATION»(/acura/mdx/ii-2010-2013/remont/mechanical/#intake-manifold-and-exhaust-system) ).
Disconnect the knock sensor 1P connector.
Check for continuity between the knock sensor 1P connector terminal and body ground. Is there continuity? YES -Repair a short in the knock sensor subharness, then go to step 19 . NO -Go to step 17.
Check for an open in the knock sensor subharness. Is the harness OK? YES -Go to step 18. NO -Repair an open in the knock sensor subharness, then go to step 19 .
Replace the knock sensor (see «KNOCK SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ).
Install the injector base (see «INJECTOR BASE REMOVAL AND INSTALLATION»(/acura/mdx/ii-2010-2013/remont/mechanical/#intake-manifold-and-exhaust-system) ), and the intake manifold (see «INSTALLATION»(/acura/mdx/ii-2010-2013/remont/mechanical/#intake-manifold-and-exhaust-system) ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Hold the engine speed at 3, 000-4, 000 rpm for at least 10 seconds.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0325 indicated? YES -Check for poor connections or loose terminals at the knock sensor and the PCM, then go to step 27 . NO -Go to step 26.
Monitor the OBD STATUS for DTC P0325 in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 25 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the knock sensor and the PCM, then go to step 1 . If the HDS indicates NOT COMPLETED, go to step 24 .
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
Hold the engine speed at 3, 000-4, 000 rpm for at least 10 seconds.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0325 indicated? YES -Check for poor connections or loose terminals at the knock sensor and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 28 . If the PCM was substituted, go to step 1 . NO -Go to step 31.
Monitor the OBD STATUS for DTC P0325 in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs were indicated in step 30 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the knock sensor and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 28 . If the PCM was substituted, go to step 1 . If the HDS indicates NOT COMPLETED, go to step 28 .

DTC P0335: CKP Sensor No Signal

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 57

Scheme 57: DTC P0335: CKP Sensor No Signal

Scheme 58

Scheme 59

Scheme 60

Scheme 61

Scheme 62

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0335 indicated? YES -Go to step 5. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the CKP sensor and the PCM.
Turn the ignition switch to LOCK (0).
Disconnect the CKP sensor 3P connector.
Turn the ignition switch to ON (II).
Measure the voltage between CKP sensor 3P connector terminal No. 3 and body ground. Is there battery voltage? YES -Go to step 9. NO -Repair an open in the wire between the CKP sensor and the under-hood fuse/relay box (PGM-FI main relay 1), then go to step 19 .
Measure the voltage between CKP sensor 3P connector terminal No. 1 and body ground. Is there about 5 V? YES -Go to step 10. NO -Go to step 11 .
Measure the voltage between CKP sensor 3P connector terminals No. 2 and No. 3. Is there battery voltage? YES -Go to step 17 . NO -Repair an open in the wire between the CKP sensor and G101, then go to step 19 .
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connector B (49P).
Check for continuity between PCM connector terminal B45 and body ground. Is there continuity? YES -Repair a short in the wire between the PCM (B45) and the CKP sensor, then go to step 19 . NO -Go to step 15.
Connect CKP sensor 3P connector terminal No. 1 to body ground with a jumper wire.
Check for continuity between PCM connector terminal B45 and body ground. Is there continuity? YES -Go to step 25 . NO -Repair an open in the wire between the PCM (B45) and the CKP sensor, then go to step 19 .
Turn the ignition switch to LOCK (0).
Replace the CKP sensor (see «CMP SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Do the CKP pattern clear/CKP pattern learn procedure (see «HDS CLEAR COMMAND»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__hds-clear-command) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0335 indicated? YES -Check for poor connections or loose terminals at the CKP sensor and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0335 indicated? YES -Check for poor connections or loose terminals at the CKP sensor and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P0339: CKP Sensor Circuit Intermittent Interruption

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine, and let it idle for 10 seconds.
Monitor the OBD STATUS for DTC P0339 in the DTCs MENU with the HDS. Does the HDS indicate FAILED? YES -Go to step 7 . NO -If the HDS indicates PASSED, go to step 5. If the HDS indicates NOT COMPLETED, keep idling until the result comes on.
Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters: ENGINE SPEED VEHICLE SPEED
Monitor the OBD STATUS for DTC P0339 in the DTCs MENU with the HDS. Does the HDS indicate FAILED? YES -Go to step 7. NO -If the HDS indicates PASSED, intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the CKP sensor and the PCM. If the HDS indicates NOT COMPLETED, go to step 5 and recheck.
Check for poor connections or loose terminals at these locations: CKP sensor PCM Engine ground Body ground Are the connections and terminals OK? YES -Go to step 8. NO -Repair the connections or the terminals, then go to step 11 .
Remove the oil pan (see «CONNECTING ROD JOURNAL CODE LOCATIONS (LETTERS OR BARS)»(/acura/mdx/ii-2010-2013/remont/mechanical/#engine-block) ), and check for damage to the CKP pulse plate. Is the CKP pulse plate damaged? YES -Replace the CKP pulse plate (see «CKP PULSE PLATE REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/mechanical/#engine-block) ), then go to step 11 . NO -Go to step 9.
Turn the ignition switch to LOCK (0).
Replace the CKP sensor (see «CMP SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ).
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Do the CKP pattern clear/CKP pattern learn procedure (see «HDS CLEAR COMMAND»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__hds-clear-command) ).
Start the engine, and let it idle for 10 seconds.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0339 indicated? YES -Check for poor connections or loose terminals at the CKP sensor and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P0351: No. 1 Cylinder Ignition Coil Circuit Malfunction; DTC P0352: No. 2 Cylinder Ignition Coil Circuit Malfunction; DTC P0353: No. 3 Cylinder Ignition Coil Circuit Malfunction; DTC P0354: No. 4 Cylinder Ignition Coil Circuit Malfunction; DTC P0355: No. 5 Cylinder Ignition Coil Circuit Malfunction; DTC P0356: No. 6 Cylinder Ignition Coil Circuit Malfunction

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 63

Scheme 63: DTC P0351: No. 1 Cylinder Ignition Coil Circuit Malfunction; DTC P0352: No. 2 Cylinder Ignition Coil

Scheme 64

Scheme 65

Scheme 66

Scheme 67

Scheme 68

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0351, P0352, P0353, P0354, P0355, and/or P0356 indicated? YES -Go to step 5. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the ignition coil(s) and the PCM.
Turn the ignition switch to LOCK (0).
Exchange the ignition coil from the problem cylinder with one from another cylinder.
Start the engine.
Check for Pending or Confirmed DTCs with the HDS. Is an ignition coil DTC indicated at the exchanged cylinder? YES -Replace the faulty ignition coil (see «IGNITION COIL AND SPARK PLUG REMOVAL/INSTALLATION»(/acura/mdx/ii-2010-2013/remont/ignition-system/#ignition-system) ), then go to step 25 . NO -Go to step 9.
Turn the ignition switch to LOCK (0).
Check the No. 9 IGN COIL + (15 A) fuse in the under-hood fuse/relay box. Is the (use OK? YES -Go to step 11. NO -Go to step 12 .
Test the ignition coil relay (built into the relay control module) (see «RELAY CONTROL MODULE TEST»(/acura/mdx/ii-2010-2013/remont/body-electrical/#relays__relay-control-module-test) ). Is the relay OK? YES -Go to step 15 . NO -Replace the under-hood fuse/relay box (see «DTC B1065: RELAY CONTROL MODULE LOST COMMUNICATION WITH DRIVER'S MPCS UNIT (DRLOCKSW MESSAGE)»(/acura/mdx/ii-2010-2013/remont/fuses-circuit-breakers/#under-hood-fuserelay-box__dtc-b1065-relay-control-module-lost) ), then go to step 25 .
Disconnect under-hood fuse/relay box connector H (9P).
Disconnect all ignition coil 3P connectors.
Check for continuity between No. 1 ignition coil 3P connector terminal No. 3 and body ground. Is there continuity? YES -Repair a short in the wire between the ignition coil and the under-hood fuse/relay box (ignition coil relay). Also replace the No. 9 IGN COIL + (15 A) fuse, then go to step 25 . NO -Check the under-hood fuse/relay box, and replace it if needed (see «DTC B1065: RELAY CONTROL MODULE LOST COMMUNICATION WITH DRIVER'S MPCS UNIT (DRLOCKSW MESSAGE)»(/acura/mdx/ii-2010-2013/remont/fuses-circuit-breakers/#under-hood-fuserelay-box__dtc-b1065-relay-control-module-lost) ), then go to step 25 .
Reconnect all connectors.
Disconnect the ignition coil 3P connector from the problem cylinder.
Turn the ignition switch to ON (II).
Measure the voltage between ignition coil 3P connector terminal No. 3 of the problem cylinder and body ground (see table). PROBLEM CYLINDER DTC No. 1 P0351 No. 2 P0352 No. 3 P0353 No. 4 P0354 No. 5 P0355 No. 6 P0356 Is there battery voltage? YES -Go to step 19. NO -Repair an open in the wire between the ignition coil and the under-hood fuse/relay box (ignition coil relay), then go to step 25 .
Turn the ignition switch to LOCK (0).
Check for continuity between ignition coil 3P connector terminal No. 2 of the problem cylinder and body ground (see table). PROBLEM CYLINDER DTC No. 1 P0351 No. 2 P0352 No. 3 P0353 No. 4 P0354 No. 5 P0355 No. 6 P0356 Is there continuity? YES -Go to step 21. NO -Repair an open in the wire between the ignition coil and G101, then go to step 25 .
Jump the SCS line with the HDS.
Disconnect PCM connector B (49P).
Check for continuity between body ground and the appropriate PCM connector terminal (see table). PROBLEM CYLINDER DTC PCM TERMINAL WIRE COLOR No. 1 P0351 B29 YEL/GRN No. 2 P0352 B30 BLU/RED No. 3 P0353 B22 WHT/BLU No. 4 P0354 B23 BRN No. 5 P0355 B11 BLK/RED No. 6 P0356 B12 BRN/WHT Is there continuity? YES -Repair a short in the wire between the PCM and the ignition coil, then go to step 26 . NO -Go to step 24.
Check for continuity between appropriate ignition coil 3P connector terminal No. 1 and the PCM connector terminal of the problem cylinder (see table). PROBLEM CYLINDER DTC PCM TERMINAL WIRE COLOR No. 1 P0351 B29 YEL/GRN No. 2 P0352 B30 BLU/RED No. 3 P0353 B22 WHT/BLU No. 4 P0354 B23 BRN No. 5 P0355 B11 BLK/RED No. 6 P0356 B12 BRN/WHT Is there continuity? YES -Go to step 31 . NO -Repair an open in the wire between the PCM and the ignition coil, then go to step 26 .
Turn the ignition switch to LOCK (0).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0351, P0352, P0353, P0354, P0355, and/or P0356 indicated? YES -Check for poor connections or loose terminals at the ignition coil(s) and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0351, P0352, P0353, P0354, P0355, and/or P0356 indicated? YES -Check for poor connections or loose terminals at the ignition coil(s) and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P0365: CMP Sensor Circuit No Signal

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 69

Scheme 69: DTC P0365: CMP Sensor Circuit No Signal

Scheme 70

Scheme 71

Scheme 72

Scheme 73

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0365 indicated? YES -Go to step 5. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the CMP sensor and the PCM.
Turn the ignition switch to LOCK (0).
Disconnect the CMP sensor 3P connector.
Turn the ignition switch to ON (II).
Measure the voltage between CMP sensor 3P connector terminal No. 3 and body ground. Is there battery voltage? YES -Go to step 9. NO -Repair an open in the wire between the CMP sensor and the under-hood fuse/relay box (PGM-FI main relay 1), then go to step 18 .
Measure the voltage between CMP sensor 3P connector terminal No. 1 and body ground. Is there about 5 V? YES -Go to step 10. NO -Go to step 11 .
Measure the voltage between CMP sensor 3P connector terminals No. 2 and No. 3. Is there battery voltage? YES -Go to step 16 . NO -Repair an open in the wire between the CMP sensor and G101, then go to step 18 .
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connector B (49P).
Check for continuity between PCM connector terminal. B46 and body ground. Is there continuity? YES -Repair a short in the wire between the PCM (B46) and the CMP sensor, then go to step 18 . NO -Go to step 15.
Check for continuity between CMP sensor 3P connector terminal No. 1 and PCM connector terminal B46. Is there continuity? YES -Go to step 23 . NO -Repair an open in the wire between the PCM (B46) and the CMP sensor, then go to step 18 .
Turn the ignition switch to LOCK (0).
Replace the CMP sensor (see «CMP SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0365 indicated? YES -Check for poor connections or loose terminals at the CMP sensor and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0365 indicated? YES -Check for poor connections or loose terminals at the CMP sensor and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ) then recheck. If the PCM was substituted, go to step 1 . NO -If the PCM was updated. Troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P0369: CMP Sensor Circuit Intermittent Interruption

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine, and let it idle for 10 seconds.
Monitor the OBD STATUS for DTC P0369 in the DTCs MENU with the HDS. Does the HDS indicate FAILED? YES -Go to step 7 . NO -If the HDS indicates PASSED, go to step 5. If the HDS indicates NOT COMPLETED, keep idling until the result comes on.
Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters: ENGINE SPEED VEHICLE SPEED
Monitor the OBD STATUS for DTC P0369 in the DTCs MENU with the HDS. Does the HDS indicate FAILED? YES -Go to step 7. NO -If the HDS indicates PASSED, intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the CMP sensor and the PCM. If the HDS indicates NOT COMPLETED, go to step 5 and recheck.
Check for poor connections or loose terminals at these locations: CMP sensor PCM Engine ground Body ground Are the connections and terminals OK? YES -Go to step 8. NO -Repair the connections or the terminals, then go to step 11 .
Check for damage to the front camshaft pulley (CMP pulse plate) (see «CMP SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ). Is the CMP pulse plate damaged? YES -Replace the front camshaft pulley (CMP pulse plate) (see «CMP SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ). Also, if needed, check the camshaft end play (see «CAMSHAFT INSPECTION»(/acura/mdx/ii-2010-2013/remont/mechanical/#cylinder-head) ), then go to step 11 . NO -Go to step 9.
Turn the ignition switch to LOCK (0).
Replace the CMP sensor (see «CMP SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ).
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Start the engine, and let it idle for 10 seconds.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0369 indicated? YES -Check for poor connections or loose terminals at the CMP sensor and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P050A: Cold Start Idle Air Control System Performance Problem

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Turn the ignition switch to ON (II).
Check for Pending or Confirmed DTCs with the HDS. Are any Pending or Confirmed DTCs other than P050A indicated? YES -Go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -Go to step 3.
Check for poor connections or a blockage in the intake air duct. Is it OK? YES -Go to step 4. NO -Reconnect or repair the intake air duct, then go to step 19 .
Check for damage to the air cleaner housing. Is it OK? YES -Go to step 5. NO -Replace the air cleaner housing (see «AIR CLEANER REMOVAL/INSTALLATION»(/acura/mdx/ii-2010-2013/remont/mechanical/#intake-air-system) ), then go to step 19 .
Check for dirt or debris in the air cleaner element. Is it dirty? YES -Replace the air cleaner element or remove the debris (see «AIR CLEANER REMOVAL/INSTALLATION»(/acura/mdx/ii-2010-2013/remont/mechanical/#intake-air-system) ), then go to step 19 . NO -Go to step 6.
Let the engine cool until the value of EGT SENSOR 1 is 131 °F (55 °C) or less.
Clear the DTC with the HDS.
Start the engine, and let it idle for 10 seconds or more.
Monitor the OBD STATUS for DTC P050A in the DTCs MENU with the HDS. Does the HDS indicate FAILED? YES -Go to step 10. NO -If the HDS indicates PASSED, intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the throttle body, the MAF sensor/IAT sensor, and PCM. If the HDS indicates EXECUTING, keep idling until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 6 .
Do the ETCS TEST in the INSPECTION MENU with the HDS. Is the THROTTLE ACTUATOR CONTROL VALVE normal? YES -Go to step 11. NO -Replace the throttle body (see «THROTTLE BODY REMOVAL/INSTALLATION»(/acura/mdx/ii-2010-2013/remont/mechanical/#intake-air-system__throttle-body-removalinstallation) ), then go to step 19 .
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
While holding the engine speed at 2, 500 rpm for 30 seconds, check the MAF SENSOR in the DATA LIST with the HDS. Is there about 9.8-11.9 gm/s? YES -Go to step 13. NO -Replace the MAF sensor/IAT sensor (see «MAF SENSOR/IAT SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ), then go to step 19 .
Turn the ignition switch to LOCK (0).
Allow the engine to cool to the ambient temperature.
Note the ambient temperature.
Turn the ignition switch to ON (II).
Quickly note the value of the IAT SENSOR in the DATA LIST with the HDS.
Compare the value of the IAT SENSOR and the ambient temperature. Does the value of the IAT SENSOR differ 5.4 °F (3 °C) or more from the ambient temperature? YES -Replace the MAF sensor/IAT sensor (see «MAF SENSOR/IAT SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ), then go to step 19. NO -Check for dirt, carbon, or damage in the throttle bore. If there is dirt or carbon, clean the throttle body (see «THROTTLE BODY TEST»(/acura/mdx/ii-2010-2013/remont/mechanical/#intake-air-system) ), then go to step 19. If there is damage to the throttle bore, replace the throttle body (see «THROTTLE BODY REMOVAL/INSTALLATION»(/acura/mdx/ii-2010-2013/remont/mechanical/#intake-air-system__throttle-body-removalinstallation) ), then go to step 19.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Let the engine cool until the value of ECT SENSOR 1 is 131 °F (55 °C) or less.
Start the engine, and let it idle for 10 seconds or more.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P050A indicated? YES -Check for poor connections or loose terminals at the throttle body, the MAF sensor/IAT sensor, and the PCM, then go to step 1 . NO -Go to step 25.
Monitor the OBD STATUS for DTC P050A in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 24 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the throttle body, the MAF sensor/IAT sensor, and the PCM, then go to step 1 . If the HDS indicates EXECUTING, keep idling until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 22 .

DTC P050B: Cold Start Ignition Timing Control System Performance Problem

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Turn the ignition switch to ON (II).
Check for Pending or Confirmed DTCs with the HDS. Are any Pending or Confirmed DTCs other than P050B indicated? YES -Go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -Go to step 3.
Check for poor connections or a blockage in the intake air duct. Is it OK? YES -Go to step 4. NO -Reconnect or repair the intake air duct, then go to step 21 .
Check for damage to the air cleaner housing. Is it OK? YES -Go to step 5. NO -Replace the air cleaner housing (see «AIR CLEANER REMOVAL/INSTALLATION»(/acura/mdx/ii-2010-2013/remont/mechanical/#intake-air-system) ), then go to step 21 .
Check for dirt or debris in the air cleaner element. Is it dirty? YES -Replace the air cleaner element or remove the debris (see «AIR CLEANER REMOVAL/INSTALLATION»(/acura/mdx/ii-2010-2013/remont/mechanical/#intake-air-system) ), then go to step 21 . NO -Go to step 6.
Let the engine cool until the value of ECT SENSOR 1 is 131 °F (55 °C) or less.
Clear the DTC with the HDS.
Start the engine, and let it idle for 10 seconds or more.
Monitor the OBD STATUS for DTC P050B in the DTCs MENU with the HDS. Does the HDS indicate FAILED? YES -Go to step 10. NO -If the HDS indicates PASSED, intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the CKP sensor, the throttle body, the MAF sensor/IAT sensor, ECT sensor 1, ECT sensor 2, and the PCM. If the HDS indicates EXECUTING, keep idling until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 6 .
Inspect the ignition timing (see «IGNITION TIMING INSPECTION»(/acura/mdx/ii-2010-2013/remont/ignition-system/#ignition-system) ). Is the ignition timing OK? YES -Go to step 12 . NO -Go to step 11.
Check for damage to the CKP sensor (see «CMP SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ) and the CKP pulse plate (see «CKP PULSE PLATE REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/mechanical/#engine-block) ). Is the CKP sensor and/or the CKP pulse plate damaged? YES -Replace the CKP sensor (see «CMP SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ) and/or the CKP pulse plate (see «CKP PULSE PLATE REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/mechanical/#engine-block) ), then go to step 21 . NO -Go to step 28 .
Do the ETCS TEST in the INSPECTION MENU with the HDS. Is the THROTTLE ACTUATOR CONTROL VALVE normal? YES -Go to step 13. NO -Replace the throttle body (see «THROTTLE BODY REMOVAL/INSTALLATION»(/acura/mdx/ii-2010-2013/remont/mechanical/#intake-air-system__throttle-body-removalinstallation) ), then go to step 21 .
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
While holding the engine speed at 2, 500 rpm for 30 seconds, check the MAF SENSOR in the DATA LIST with the HDS. Is there about 9.8-11.9 gm/s? YES -Go to step 15. NO -Replace the MAF sensor/IAT sensor (see «MAF SENSOR/IAT SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ), then go to step 21 .
Turn the ignition switch to LOCK (0).
Allow the sensors to cool to the ambient temperature.
Note the ambient temperature.
Turn the ignition switch to ON (II).
Quickly note the value of ECT SENSOR 1 and ECT SENSOR 2 in the DATA LIST with the HDS.
Compare the value of ECT SENSOR 1 and the ambient temperature, and the value of ECT SENSOR 2 and the ambient temperature individually. Does either sensor differ more than 5.4 °F (3 °C) from the ambient temperature? YES -Replace the sensor that differed more than 5.4 °F (3 °C) from the ambient temperature, then go to step 21. NO -Check and repair any problems with the following items. Repair or replace them if needed, then go to step 21. If all of the items are OK, go to step 28 . Engine compression and cylinder leakdown VTEC system Engine oil A/C system Power steering
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Let the engine cool until the value of ECT SENSOR 1 is 131 °F (55 °C) or less.
Start the engine, and let it idle for 10 seconds or more.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P050B indicated? YES -Check for poor connections or loose terminals at the CKP sensor, the throttle body, the MAF sensor/IAT sensor, ECT sensor 1, ECT sensor 2, and the PCM, then go to step 1 . NO -Go to step 27.
Monitor the OBD STATUS for DTC P050B in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 26 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the CKP sensor, the throttle body, the MAF sensor/IAT sensor, ECT sensor 1, ECT sensor 2, and the PCM, then go to step 1 . If the HDS indicates EXECUTING, keep idling until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 24 .
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Let the engine cool until the value of ECT SENSOR 1 is 131 °F (55 °C) or less.
Start the engine, and let it idle for 10 seconds or more.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P050B indicated? YES -Check for poor connections or loose terminals at the CKP sensor, the throttle body, the MAF sensor/IAT sensor, ECT sensor 1, ECT sensor 2, and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 30 . If the PCM was substituted, go to step 1 . NO -Go to step 33.
Monitor the OBD STATUS for DTC P050B in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs were indicated in step 32 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the CKP sensor, the throttle body, the MAF sensor/IAT sensor, ECT sensor 1, ECT sensor 2, and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 30 . If the PCM was substituted, go to step 1 . If the HDS indicates EXECUTING, keep idling until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 30 .

DTC P0560: PCM Power Source Circuit Unexpected Voltage

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 74

Scheme 74: DTC P0560: PCM Power Source Circuit Unexpected Voltage

Scheme 75

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine, and let it idle.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0560 indicated? YES -Go to step 5. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the No. 7 BACK UP FI ECU (7.5 A) fuse in the main under-hood fuse box and the PCM.
Turn the ignition switch to LOCK (0).
Check the No. 7 BACK UP FI ECU (7.5 A) fuse in the main under-hood fuse box. Is the fuse OK? YES -Go to step 7. NO -Go to step 10 .
Jump the SCS line with the HDS.
Disconnect PCM connector A (49P).
Measure the voltage between PCM connector terminal A23 and body ground. Is there battery voltage? YES -Go to step 19 . NO -Repair an open in the wire between the PCM (A23) and the No. 7 BACK UP FI ECU (7.5 A) fuse, then go to step 13 .
Jump the SCS line with the HDS.
Disconnect PCM connector A (49P).
Check for continuity between PCM connector terminal A23 and body ground. Is there continuity? YES -Repair a short in the wire between the PCM (A23) and the No. 7 BACK UP FI ECU (7.5 A) fuse. Also replace the No. 7 BACK UP FI ECU (7.5 A) fuse, then go to step 13. NO -Check the main under-hood fuse box, and replace it if needed (see «DTC B1065: RELAY CONTROL MODULE LOST COMMUNICATION WITH DRIVER'S MPCS UNIT (DRLOCKSW MESSAGE)»(/acura/mdx/ii-2010-2013/remont/fuses-circuit-breakers/#under-hood-fuserelay-box__dtc-b1065-relay-control-module-lost) ). Also replace the No. 7 BACK UP FI ECU (7.5 A) fuse, then go to step 13.
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Start the engine, and let it idle.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0560 indicated? YES -Check for poor connections or loose terminals at the No. 7 BACK UP FI ECU (7.5 A) fuse and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Start the engine, and let it idle.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0560 indicated? YES -Check for poor connections or loose terminals at the No. 7 BACK UP FI ECU (7.5 A) fuse and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 21 . If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P0562: Charging System Low Voltage

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ). If any high current load accessories are installed, this DTC can be set. If DTC P16BB and/or P16BC is stored at the same time as DTC P0562, troubleshoot DTC P16BB and/or P16BC first, then recheck for DTC P0562.

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine.
Check under these conditions: A/C on Temperature control at maximum cool Blower fan at maximum speed Rear window defogger on Headlights on high beam
Hold the engine speed at 2, 000 rpm (in P or N) for 1 minute.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0562 indicated? YES -Replace the alternator (see «TENSIONER PULLEY REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/charging-system/#charging-system) ), then go to step 7. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the alternator and the main under-hood fuse box, and check the battery performance (see «BATTERY TEST»(/acura/mdx/ii-2010-2013/remont/body-electrical/#battery) ).
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Start the engine.
Check under these conditions: A/C on Temperature control at maximum cool Blower fan at maximum speed Rear window defogger on Headlights on high beam
Hold the engine speed at 2, 000 rpm (in P or N) for 1 minute.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0562 indicated? YES -Check for poor connections or loose terminals at the alternator, the battery, and the main under-hood fuse box, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P0563: PCM Power Source Circuit Unexpected Voltage

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 76

Scheme 76: DTC P0563: PCM Power Source Circuit Unexpected Voltage

Scheme 77

Scheme 78

Scheme 79

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Turn the ignition switch to LOCK (0).
Wait 10 seconds.
Turn the ignition switch to ON (II).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0563 indicated? YES -Go to step 7. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the under-hood fuse/relay box, the No. 8 IGP (15 A) fuse, and the PCM.
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connector A (49P).
Measure the voltage between PCM connector terminal A6 and body ground. Is there battery voltage? YES -Go to step 13 . NO -Go to step 11.
Disconnect under-hood fuse/relay box connector E (14P).
Check for continuity between PCM connector terminal A6 and body ground. Is there continuity? YES -Repair a short in the wire between the PCM (A6) and the under-hood fuse/relay box, then go to step 19 . NO -Go to step 18 .
Reconnect PCM connector A (49P).
Disconnect PCM connector B (49P).
Measure the voltage between PCM connector terminal B3 and body ground. Is there battery voltage? YES -Go to step 16. NO -Go to step 18 .
Disconnect under-hood fuse/relay box connector H (9P).
Measure the voltage between PCM connector terminal B3 and body ground. Is there battery voltage? YES -Repair a short to power in the wire between the PCM (B3) and the under-hood fuse/relay box, then go to step 19 . NO -Go to step 18.
Test PGM-FI main relay 1 (built into the relay control module) (see «RELAY CONTROL MODULE TEST»(/acura/mdx/ii-2010-2013/remont/body-electrical/#relays__relay-control-module-test) ). Is PGM-FI main relay 1 OK? YES -Go to step 26 . NO -Replace the under-hood fuse/relay box (see «DTC B1065: RELAY CONTROL MODULE LOST COMMUNICATION WITH DRIVER'S MPCS UNIT (DRLOCKSW MESSAGE)»(/acura/mdx/ii-2010-2013/remont/fuses-circuit-breakers/#under-hood-fuserelay-box__dtc-b1065-relay-control-module-lost) ), then go to step 19.
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Turn the ignition switch to LOCK (0).
Wait 10 seconds.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0563 indicated? YES -Check for poor connections or loose terminals at the under-hood fuse/relay box and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0563 indicated? YES -Check for poor connections or loose terminals at the under-hood fuse/relay box and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P0602: PCM Programming Error

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ). This DTC is stored when a PCM update is not completed. Do not turn the ignition switch to ACC (I) or LOCK (0) while updating the PCM. If you do, the PCM can be damaged.

Do the PCM update procedure (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0602 indicated? YES -Replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). NO -The troubleshooting is complete.

DTC P060A: PCM Internal Control Module Malfunction

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P060A indicated? YES -Go to step 4. NO -Intermittent failure, the system is OK at this time.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P060A indicated? YES -If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P0615: Starter Cut Relay STRLD Circuit Malfunction

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ). If DTC P0705 and/or P0706 in the A/T system are stored at the same time as DTC P0615, troubleshoot DTC P0705 and/or P0706 first, then recheck for DTC P0615. If DTC P16BD and/or P16BE are stored at the same time as DTC P0615, troubleshoot DTC P16BD and/or P16BE first, then recheck for DTC P0615.

Scheme 80

Scheme 80: DTC P0615: Starter Cut Relay STRLD Circuit Malfunction

Scheme 81

Scheme 82

Scheme 83

Scheme 84

Scheme 85

Scheme 86

Scheme 87

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Turn the ignition switch to START (III), and hold it for 1 second or more.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0615 indicated? YES -Go to step 5. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at starter cut relay 1, transmission range switch and the PCM.
Try to start the engine. Does the engine start? YES -Go to step 6. NO -Go to step 13 .
Turn the ignition switch to LOCK (0).
Check the No. 1 STRLD (7.5 A) fuse in auxiliary under-dash fuse holder 1. Is the fuse OK? YES -Go to step 8. NO -Replace the fuse, then go to step 28 .
Jump the SCS line with the HDS.
Disconnect PCM connector A (49P).
Remove starter cut relay 1 (A) from the auxiliary under-dash relay block A.
Connect starter cut relay 1 4P connector terminal No. 2 to body ground with a jumper wire.
Check for continuity between PCM connector terminal A28 and body ground. Is there continuity? YES -Go to step 32 . NO -Repair an open in the wire between the PCM (A28) and starter cut relay 1, then go to step 27 .
Turn the ignition switch to LOCK (0).
Remove starter cut relay 1 (A) from the auxiliary under-dash relay block A.
Remove starter cut relay 2 (A) from the auxiliary under-dash relay block A.
Connect starter cut relay 1 4P connector terminal No. 4 to body ground with a jumper wire.
Turn the ignition switch to ON (II).
Check the STARTER RELAY CONTROL RETURN in the DATA LIST with the HDS while the ignition switch is in START (III). Is OFF indicated? YES -Go to step 19. NO -Go to step 23 .
Remove the jumper wire from starter cut relay 1 4P connector.
Turn the ignition switch to LOCK (0).
Disconnect the transmission range switch 10P connector.
At the switch side, check for continuity between transmission range switch 10P connector terminals No. 2 and No. 6 with the shift lever in N, and then in P. Is there continuity in each shift lever position? YES -Repair an open in the wire between the transmission rang switch and starter cut relay 1, starter cut relay 2, or G101, then go to step 27 . NO -Replace the transmission range switch (see «TRANSMISSION RANGE SWITCH REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/automatic-trans/#automatic-transmission) ), then go to step 27 .
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connector A (49P).
Check for continuity between PCM connector terminal A3 and body ground with the jumper wire still connected. Is there continuity? YES -Go to step 32 . NO -Repair an open in the wire between the PCM (A3) and starter cut relay 1, then go to step 27.
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0615 indicated? YES -Check for poor connections or loose terminals at starter cut relay 1 and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0615 indicated? YES -Check for poor connections or loose terminals at starter cut relay 1 and the PCM, then go to step 1 . If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P062F: PCM Internal Control Module Keep Alive Memory (KAM) Error

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Check for Pending or Confirmed DTCs with the HDS. Are any Pending or Confirmed DTCs indicated? YES -Go to step 4. NO -Intermittent failure, the system is OK at this time.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P062F indicated? YES -If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P0630: VIN Not Programmed or Mismatch

Turn the ignition switch to ON (II).
Check the VIN with the HDS. Does the HDS show the vehicle's VIN? YES -Go to step 5 . NO -Go to step 3.
Input the VIN to the PCM with the HDS. Does the HDS indicate COMPLETE? YES -Go to step 5 . NO -Go to step 4.
Check for DTCs with the HDS. Is DTC P062F indicated? YES -Go to the DTC P062F troubleshooting (see «DTC P062F: PCM INTERNAL CONTROL MODULE KEEP ALIVE MEMORY (KAM) ERROR»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__dtc-p062f-pcm-internal-control-module) ). NO -Go to step 9 .
Clear the DTC with the HDS.
Turn the ignition switch to LOCK (0).
Turn the ignition switch to ON (II), and wait 5 seconds.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0603 indicated? YES -Go to step 9. NO -Intermittent failure, the system is OK at this time. If any other Pending or Confirmed DTCs are indicated go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0630 indicated? YES -If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P0641: Sensor Reference Voltage A Malfunction

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 88

Scheme 88: DTC P0641: Sensor Reference Voltage A Malfunction

Scheme 89

Scheme 90

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0641 indicated? YES -Go to step 4. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the PCM and these parts: Throttle body Input shaft (mainshaft) speed sensor APP sensor
Turn the ignition switch to LOCK (0).
Disconnect the connectors from these parts: Throttle body Input shaft (mainshaft) speed sensor APP sensor
Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0641 indicated? YES -Go to step 10 . NO -Go to step 9.
Check for Pending or Confirmed DTCs with the HDS while connecting these parts, one at a time: Throttle body Input shaft (mainshaft) speed sensor APP sensor Is DTC P0641 indicated? YES -Replace the part that caused the DTC when it was reconnected, then go to step 14 . NO -Check for poor connections or loose terminals at the PCM and the following parts, then go to step 1 . Throttle body Input shaft (mainshaft) speed sensor APP sensor
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connectors A (49P), B (49P), and C (49P).
Check for continuity between body ground and PCM connector terminals A24, B18, and C12 individually. Is there continuity? YES -Repair a short in the wire between the PCM (A24, B18, or C12) and each part that was disconnected in step 5 , then go to step 14. NO -Go to step 20 .
Turn the ignition switch to LOCK (0).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0641 indicated? YES -Check for poor connections or loose terminals at the PCM and the following parts, then go to step 1 . Throttle body Input shaft (mainshaft) speed sensor APP sensor NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0641 indicated? YES -If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, check for poor connections or loose terminals at the PCM and the following parts, then go to step 1 . Throttle body Input shaft (mainshaft) speed sensor APP sensor NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P0651: Sensor Reference Voltage B Malfunction

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 91

Scheme 91: DTC P0651: Sensor Reference Voltage B Malfunction

Scheme 92

Scheme 93

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0651 indicated? YES -Go to step 4. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the PCM and these parts: MAP sensor Output shaft (countershaft) speed sensor IMT actuator EGR valve APP sensor FTP sensor
Turn the ignition switch to LOCK (0).
Disconnect the connectors from these parts: MAP sensor Output shaft (countershaft) speed sensor IMT actuator EGR valve APP sensor FTP sensor
Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0651 indicated? YES -Go to step 10 . NO -Go to step 9.
Check for Pending or Confirmed DTCs with the HDS while connecting these parts, one at a time: MAP sensor Output shaft (countershaft) speed sensor IMT actuator EGR valve APP sensor FTP sensor Is DTC P0651 indicated? YES -Replace the part that caused the DTC when it was reconnected, then go to step 14 . NO -Check for poor connections or loose terminals at the PCM and the following parts, then go to step 1 . MAP sensor Output shaft (countershaft) speed sensor IMT actuator EGR valve APP sensor FTP sensor
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connectors A (49P), B (49P), and C (49P).
Check for continuity between body ground and PCM connector terminals A25, B36, and C11 individually. Is there continuity? YES -Repair a short in the wire between the PCM (A25, B36, or C11) and each part that was disconnected in step 5 , then go to step 14. NO -Go to step 20 .
Turn the ignition switch to LOCK (0).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0651 indicated? YES -Check for poor connections or loose terminals at the PCM and the following parts, then go to step 1 . MAP sensor Output shaft (countershaft) speed sensor IMT actuator EGR valve APP sensor FTP sensor NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0651 indicated? YES -If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, check for poor connections or loose terminals at the PCM and the following parts, then go to step 1 . MAP sensor Output shaft (countershaft) speed sensor IMT actuator EGR valve APP sensor FTP sensor NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P0685: PCM Power Control Circuit/Internal Circuit Malfunction

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ). If the problem does not return after you clear the DTC, or it this DTC is stored intermittently, check for loose terminals at the IGP line connectors before replacing the PCM.

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine, and let it idle for 30 seconds.
Turn the ignition switch to LOCK (0).
Start the engine, and let it idle for 30 seconds.
Turn the ignition switch to LOCK (0).
Turn the ignition switch to ON (II).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P0685 indicated? YES -Go to step 9. NO -Intermittent failure, the system is OK at this time.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Start the engine, and let it idle for 30 seconds.
Turn the ignition switch to LOCK (0).
Start the engine, and let it idle for 30 seconds.
Turn the ignition switch to LOCK (0).
Turn the ignition switch to ON (II). Is DTC P0685 indicated? YES -If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 10 . If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P1109: BARO Sensor Circuit Out of Range High

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Reset the PCM with the HDS.
Start the engine.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P1109 indicated? YES -Go to step 4. NO -Intermittent failure, the system is OK at this time. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P1109 indicated? YES -If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P1116: ECT Sensor 1 Circuit Range/Performance Problem

Check for poor connections or loose terminals at ECT sensor 1 and ECT sensor 2. Are the connections and terminals OK? YES -Go to step 2. NO -Repair the connectors or terminals, then go to step 21 .
Turn the ignition switch to ON (II).
Check for Pending or Confirmed DTCs with the HDS. Are DTC P1116 and P2183 indicated at the same time? YES -Go to step 12 . NO -Go to step 4.
Start the engine, and let it idle for 10 minutes.
Check ECT SENSOR 1 in the DATA LIST with the HDS. Is about 109 °F (43 °C) or less indicated? YES -Replace ECT sensor 1 (see «ECT SENSOR 1 REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ), then go to step 21 . NO -Go to step 6.
Turn the ignition switch to LOCK (0).
Allow ECT sensor 1 to cool to the ambient temperature.
Note the ambient temperature.
Turn the ignition switch to ON (II).
Quickly note the value of ECT SENSOR 1 in the DATA LIST with the HDS.
Compare the value of ECT SENSOR 1 and the ambient temperature. Does the value of ECT SENSOR 1 differ 5.4 °F (3 °C) or more from the ambient temperature? YES -Replace ECT sensor 1 (see «ECT SENSOR 1 REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ), then go to step 21 . NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at ECT sensor 1, ECT sensor 2, and the PCM.
Start the engine, and let it idle for 10 minutes.
Check ECT SENSOR 1 in the DATA LIST with the HDS. Is about 109 °F (43 °C) or less indicated? YES -Replace ECT sensor 1 (see «ECT SENSOR 1 REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ), then go to step 21 . NO -Go to step 14.
Check ECT SENSOR 2 in the DATA LIST with the HDS. Is about 109 °F (43 °C) or less indicated? YES -Replace ECT sensor 2 (see «ECT SENSOR 2 REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ), then go to step 21 . NO -Go to step 15.
Turn the ignition switch to LOCK (0).
Allow the sensors to cool to the ambient temperature.
Note the ambient temperature.
Turn the ignition switch to ON (II).
Quickly note the value of ECT SENSOR 1 and ECT SENSOR 2 in the DATA LIST with the HDS.
Compare the value of ECT SENSOR 1 and the ambient temperature, and the value of ECT SENSOR 2 and the ambient temperature individually. Does one of the sensors differ more than 5.4 °F (3 °C) from the ambient temperature? YES -Replace the sensor that differed more than 5.4 °F (3 °C) from the ambient temperature, then go to step 21. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at ECT sensor 1, ECT sensor 2, and the PCM.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P1116 indicated? YES -Check for poor connections or loose terminals at ECT sensor 1, ECT sensor 2, and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P1128: MAP Sensor Signal Lower Than Expected

Turn the ignition switch to ON (II).
Check the MAP SENSOR in the DATA LIST with the HDS. Is less than 54.1 kPa (16.0 inHg, 406 mmHg) or 1.61 V held for more than 5 seconds? YES -Go to step 7 . NO -Go to step 3.
Clear the DTC with the HDS.
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
Test-drive under these conditions: Engine coolant temperature (ECT SENSOR 1) above 158°F (70°C) Engine speed about 1, 200 rpm or more Transmission in D Vehicle speed about 15 mph (24 km/h) or more under half throttle Drive 2 seconds or more
Monitor the OBD STATUS for DTC P1128 in the DTCs MENU with the HDS. Does the HDS indicate FAILED? YES -Go to step 7. NO -If the HDS indicates PASSED, intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the MAP sensor and the PCM. If the HDS indicates NOT COMPLETED, go to step 4 and recheck.
Turn the ignition switch to LOCK (0).
Replace the MAP sensor (see «MAP SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ).
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
Test-drive under these conditions: Engine coolant temperature (ECT SENSOR 1) above 158°F (70°C) Engine speed about 1, 200 rpm or more Transmission in D Vehicle speed about 15 mph (24 km/h) or more under half throttle Drive 2 seconds or more
Check for Pending or Confirmed DTCs with the HDS. Is DTC P1128 indicated? YES -Check for poor connections or loose terminals at the MAP sensor and the PCM, then go to step 1 . NO -Go to step 15.
Monitor the OBD STATUS for DTC P1128 in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 14 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the MAP sensor and the PCM, then go to step 1 . If the HDS indicates NOT COMPLETED, go to step 12 .

DTC P1129: MAP Sensor Signal Higher Than Expected

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Check for vacuum leaks at these parts: PCV valve PCV hose EVAP canister purge valve Throttle body Intake manifold Brake booster Brake booster hose Are there any vacuum leaks? YES -Repair or replace the part(s) with vacuum leaks, then go to step 9 . NO -Go to step 2.
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
Check the MAP SENSOR in the DATA LIST with the HDS. Is there more than 36.9 kPa (11.0 inHg, 277 mmHg) or 1.14 V held for more than 5 seconds? YES -Go to step 7 . NO -Go to step 4.
Clear the DTC with the HDS.
Test-drive under these conditions: Engine coolant temperature (ECT SENSOR 1) above 158°F (70°C) Engine speed between 1, 200-5, 900 rpm Transmission in D Drive at a steady speed between 55-75 mph (88-120 km/h) for 10 seconds, then decelerate (with the throttle fully closed) for 2 seconds.
Monitor the OBD STATUS for DTC P1129 in the DTCs MENU with the HDS. Does the HDS indicate FAILED? YES -Go to step 7. NO -If the HDS indicates PASSED, intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the MAP sensor and the PCM. If the HDS indicates NOT COMPLETED, go to step 5 and recheck.
Turn the ignition switch to LOCK (0).
Replace the MAP sensor (see «MAP SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ).
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
Test-drive under these conditions: Engine coolant temperature (ECT SENSOR 1) above 158°F (70°C) Engine speed between 1, 200-5, 900 rpm Transmission in D Drive at a steady speed between 55-75 mph (88-120 km/h) for 10 seconds, then decelerate (with the throttle fully closed) for 2 seconds.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P1129 indicated? YES -Check for poor connections or loose terminals at the MAP sensor and the PCM, then go to step 1 . NO -Go to step 15.
Monitor the OBD STATUS for DTC P1129 in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 14 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the MAP sensor and the PCM, then go to step 1 . If the HDS indicates NOT COMPLETED, go to step 12 .

DTC P1172: Rear A/F Sensor (Bank 1, Sensor 1) Circuit Out of Range High; DTC P1174: Front A/F Sensor (Bank 2, Sensor 1) Circuit Out of Range High

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
Monitor the OBD STATUS for P1172 and/or P1174* in the DTCs MENU with the HDS. Does the HDS indicate FAILED? YES -Go to step 5. NO -If the HDS indicates PASSED, intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM. If the HDS indicates EXECUTING, keep idling until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 3 and recheck.
Turn the ignition switch to LOCK (0).
Replace the A/F sensor (Sensor 1) (see «A/F SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__af-sensor-replacement) ).
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P1172 and/or P1174* indicated? YES -Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM, then go to step 1 . NO -Go to step 12.
Monitor the OBD STATUS for DTC P1172 and/or P1174* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 11 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM, then go to step 1 . If the HDS indicates EXECUTING, keep idling until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 10 .

DTC P1297: ELD Circuit Low Voltage

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 94

Scheme 94: DTC P1297: ELD Circuit Low Voltage

Turn the ignition switch to ON (II).
Check the ELD in the DATA LIST with the HDS. Is 72 A or more indicated? YES -Go to step 3. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the ELD and the PCM.
Turn the ignition switch to LOCK (0).
Disconnect the ELD 3P connector.
Turn the ignition switch to ON (II).
Check the ELD in the DATA LIST with the HDS. Is 72 A or more indicated? YES -Go to step 7. NO -Go to step 11 .
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connector A (49P).
Check for continuity between PCM connector terminal A10 and body ground. Is there continuity? YES -Repair a short in the wire between the PCM (A10) and the ELD, then go to step 13 . NO -Go to step 20 .
Turn the ignition switch to LOCK (0).
Replace the left side engine compartment wire harness (see «CONNECTOR TO HARNESS INDEX»(/acura/mdx/ii-2010-2013/remont/body-electrical/#connectors-and-harnesses__connector-to-harness-index) ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Start the engine.
Turn on the headlights.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P1297 indicated? YES -Check for poor connections or loose terminals at the ELD unit and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Start the engine.
Turn on the headlights.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P1297 indicated? YES -Check for poor connections or loose terminals at the ELD unit and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 22 . If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P1298: ELD Circuit High Voltage

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 95

Scheme 95: DTC P1298: ELD Circuit High Voltage

Scheme 96

Scheme 97

Start the engine, and let it idle.
Check the ELD in the DATA LIST with the HDS. Is 0.2 A or less indicated? YES -Go to step 3. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the ELD and the PCM.
Turn the ignition switch to LOCK (0).
Disconnect the ELD 3P connector.
Turn the ignition switch to ON (II).
Measure the voltage between ELD 3P connector terminal No. 1 and body ground. Is there battery voltage? YES -Go to step 7. NO -Repair an open in the wire between the No. 18 ACG (10 A) fuse in the under-dash fuse/relay box and the ELD, then go to step 13 .
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connector A (49P).
Check for continuity between PCM connector terminal A10 and ELD 3P connector terminal No. 3. Is there continuity? YES -Go to step 11. NO -Repair an open in the wire between the PCM (A10) and the ELD, then go to step 13 .
Check for continuity between ELD 3P connector terminal No. 2 and body ground. Is there continuity? YES -Go to step 12. NO -Repair an open in the wire between the ELD and G302, then go to step 13 .
Replace the left side engine compartment wire harness (see «CONNECTOR TO HARNESS INDEX»(/acura/mdx/ii-2010-2013/remont/body-electrical/#connectors-and-harnesses__connector-to-harness-index) ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P1298 indicated? YES -Go to step 18. NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P1298 indicated? YES -Check for poor connections or loose terminals at the ELD unit and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P1549: Charging System High Voltage

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine.
Check under these conditions: A/C off Headlights off Rear window defogger off
Hold the engine speed at 2, 000 rpm (in P or N) for 1 minute.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P1549 indicated? YES -Replace the alternator (see «TENSIONER PULLEY REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/charging-system/#charging-system) ), then go to step 7. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the alternator and the main under-hood fuse box.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Start the engine.
Check under these conditions: A/C off Headlights off Rear window defogger off
Hold the engine speed at 2, 000 rpm (in P or N) for 1 minute.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P1549 indicated? YES -Check for poor connections or loose terminals at the alternator and the main under-hood fuse box, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P16BB: Alternator B Terminal Circuit Low Voltage

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine.
Check under these conditions: A/C on Temperature control at maximum cool Blower fan at maximum speed Rear window defogger on Headlights on high beam
Hold the engine speed at 2, 000 rpm (in P or N) for 1 minute.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P16BB indicated? YES -Go to step 7. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the alternator and the main under-hood fuse box, and check the battery performance (see «BATTERY TEST»(/acura/mdx/ii-2010-2013/remont/body-electrical/#battery) ).
Check for poor connections or loose terminals at the alternator and the main under-hood fuse box Are the connections and terminals OK? YES -Go to step 8. NO -Repair the connections or terminals, then go to step 9 .
Check for an open in the wire between the alternator and the main under-hood fuse box at the starter subharness. Is the harness OK? YES -Replace the alternator (see «TENSIONER PULLEY REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/charging-system/#charging-system) ), then go to step 9. NO -Repair an open in the wire between the alternator and the main under-hood fuse box, then go to step 9.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Start the engine.
Check under these conditions: A/C on Temperature control at maximum cool Blower fan at maximum speed Rear window defogger on Headlights on high beam
Hold the engine speed at 2, 000 rpm (in P or N) for 1 minute.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P16BB indicated? YES -Check for poor connections or loose terminals at the alternator and the main under-hood fuse box, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P16BC: Alternator FR Terminal Circuit/IGP Circuit Low Voltage

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 98

Scheme 98: DTC P16BC: Alternator FR Terminal Circuit/IGP Circuit Low Voltage

Scheme 99

Scheme 100

Check for poor connections or loose terminals at the alternator 4P connector. Are the connections and terminals OK? YES -Go to step 2. NO -Repair the connections or terminals, then go to step 18 .
Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine.
Check under these conditions: A/C on Temperature control at maximum cool Blower fan at maximum speed Rear window defogger on Headlights on high beam
Hold the engine speed 2, 000 rpm (in P or N) for 1 minute.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P16BC indicated? YES -Go to step 8. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the alternator.
Turn the ignition switch to LOCK (0).
Disconnect the alternator 4P connector.
Turn the ignition switch to ON (II).
Measure the voltage between alternator 4P connector terminal No. 1 and body ground. Is there battery voltage? YES -Go to step 12. NO -Repair an open in the wire between the alternator (IG1 line) and the No. 18 ACG (10 A) fuse in the under-dash fuse/relay box, then go to step 17 .
Measure the voltage between alternator 4P connector terminal No. 4 and body ground. Is there about 5 V? YES -Replace the alternator (see «TENSIONER PULLEY REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/charging-system/#charging-system) ), then go to step 17 . NO -Go to step 13.
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connector C (44P).
Check for continuity between alternator 4P connector terminal No. 4 and PCM connector terminal C44. Is there continuity? YES -Go to step 26 . NO -Repair an open in the wire between the PCM (C44) and the alternator, then go to step 18 .
Turn the ignition switch to LOCK (0).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Start the engine.
Check under these conditions: A/C on Temperature control at maximum cool Blower fan at maximum speed Rear window defogger on Headlights on high beam
Hold the engine speed 2, 000 rpm (in P or N) for 1 minute.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P16BC indicated? YES -Check for poor connections or loose terminals at the alternator and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Start the engine.
Check under these conditions: A/C on Temperature control at maximum cool Blower fan at maximum speed Rear window defogger on Headlights on high beam
Hold the engine speed 2, 000 rpm (in P or N) for 1 minute.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P16BC indicated? YES -Check for poor connections or loose terminals at the alternator and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 28 . If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P16BD: Starter Cut Relay 2 Malfunction

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 101

Scheme 101: DTC P16BD: Starter Cut Relay 2 Malfunction

Scheme 102

Scheme 103

Scheme 104

Turn the ignition switch to ON (II).
Clear the DTC with the HDS, and wait 5 seconds.
Check the STARTER CUT RELAY in the DATA LIST with the HDS. Is 2.2 V or less indicated? YES -Go to step 4. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at starter cut relay 1, starter cut relay 2, and the PCM.
Try to start the engine. Does the engine start? YES -Go to step 5. NO -Go to step 11 .
Turn the ignition switch to LOCK (0).
Check the No. 1 STRLD (7.5 A) fuse in auxiliary under-dash fuse holder 1. Is the fuse OK? YES -Replace starter cut relay 2, then go to step 20 . NO -Go to step 7.
Remove the blown fuse from auxiliary under-dash fuse holder 1.
Jump the SCS line with the HDS.
Disconnect PCM connector A (49P).
Check for continuity between PCM connector terminal A28 and body ground. Is there continuity? YES -Repair a short in the wire between the PCM (A28) and auxiliary under-dash fuse holder 1, Also replace the No. 1 STRLD (7.5 A) fuse, then go to step 19 . NO -Replace the No. 1 STRLD (7.5 A) fuse, then go to step 19 .
Remove starter cut relay 1 (A) from the auxiliary under-dash relay block A.
Check the STARTER CUT RELAY in the DATA LIST with the HDS. Is 2.2 V or less Indicated? YES -Go to step 13. NO -Replace starter cut relay 1, then go to step 20 .
Remove starter cut relay 2 (A) from the auxiliary under-dash relay block A.
Check the STARTER CUT RELAY in the DATA LIST with the HDS. Is 2.2 V or less indicated? YES -Go to step 15. NO -Replace starter cut relay 2, then go to step 20 .
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connector A (49P).
Check for continuity between starter cut relay 1 4P connector terminal No. 2 and body ground. Is there continuity? YES -Repair a short in the wire between starter cut relay 1 and auxiliary under-dash fuse holder 1, then go to step 19. NO -Go to step 24 .
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P16BD indicated? YES -Check for poor connections or loose terminals at starter cut relay 1, starter cut relay 2, and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P16BD indicated? YES -Check for poor connections or loose terminals at starter cut relay 1, starter cut relay 2, and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P16BE: Starter Cut Relay 1 Malfunction

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 105

Scheme 105: DTC P16BE: Starter Cut Relay 1 Malfunction

Scheme 106

Turn the ignition switch to ON (II).
Clear the DTC with the HDS, and wait 5 seconds.
Check the STARTER CUT RELAY in the DATA LIST with the HDS. Is 3.2 V or more indicated? YES -Go to step 4. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at starter cut relay 1, starter cut relay 2, and the PCM.
Remove starter cut relay 1 (A) from the auxiliary under-dash relay block A.
Check the STARTER CUT RELAY in the DATA LIST with the HDS. Is 3.2 V or more indicated? YES -Go to step 6. NO -Replace starter cut relay 1, then go to step 7 .
Measure the voltage between starter cut relay 1 4P connector terminal No. 2 and body ground. Is there 3.2V or more? YES -Repair a short to power in the wire between starter cut relay 1, starter cut relay 2, and the PCM, then go to step 7. NO -Go to step 11 .
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P16BE indicated? YES -Check for poor connections or loose terminals at starter cut relay 1, starter cut relay 2, and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Turn the ignition switch to LOCK (0).
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P16BE indicated? YES -Check for poor connections or loose terminals at starter cut relay 1, starter cut relay 2, and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P16BF: Starter Cut Relay STRLY Circuit Malfunction

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 107

Scheme 107: DTC P16BF: Starter Cut Relay STRLY Circuit Malfunction

Scheme 108

Scheme 109

Scheme 110

Turn the ignition switch to ON (II).
Clear the DTC with the HDS, and wait 5 seconds.
Check the STARTER RELAY CONTROL RETURN in the DATA LIST with the HDS. Is OFF Indicated? YES -Go to step 4. NO -Go to step 14 .
Turn the ignition switch to START (III), and hold it for 5 seconds or more.
Check the STARTER RELAY CONTROL RETURN in the DATA LIST with the HDS while the ignition switch is in START (III). Is OFF indicated? YES -Go to step 6. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at starter cut relay 1, starter cut relay 2, and the PCM.
Turn the ignition switch to LOCK (0).
Remove the IG2 cut relay, and the ACC cut relay from their soket (see «DASHBOARD»(/acura/mdx/ii-2010-2013/remont/body-electrical/#relay-and-control-unit-locations) ).
Test the IG2 cut relay, and the ACC cut relay (see «POWER RELAY TEST»(/acura/mdx/ii-2010-2013/remont/body-electrical/#relays__power-relay-test) ). Are the relays OK? YES -Go to step 9. NO -Replace the IG2 cut relay, and/or ACC cut relay, then go to step 24 .
Remove starter cut relay 1 (A) and starter cut relay 2 (B) from the auxiliary under-dash relay block A.
Test starter cut relay 1 and starter cut relay 2 (see «POWER RELAY TEST»(/acura/mdx/ii-2010-2013/remont/body-electrical/#relays__power-relay-test) ). Are the relays OK? YES -Go to step 11. NO -Replace starter cut relay 1 and/or starter cut relay 2, then go to step 24 .
Jump the SCS line with the HDS.
Disconnect PCM connector A (49P).
Check for continuity between PCM connector terminal A3 and body ground. Is there continuity? YES -Repair a short in the wire between the PCM (A3) and starter cut relay 1, starter cut relay 2, or the IG2 cut relay, then go to step 24 . NO -Go to step 30 .
Turn the ignition switch to LOCK (0).
Remove the IG2 cut relay, and the ACC cut relay from their soket (see «DASHBOARD»(/acura/mdx/ii-2010-2013/remont/body-electrical/#relay-and-control-unit-locations) ).
Test the IG2 cut relay, and the ACC cut relay (see «POWER RELAY TEST»(/acura/mdx/ii-2010-2013/remont/body-electrical/#relays__power-relay-test) ). Are the relays OK? YES -Go to step 17. NO -Replace the IG2 cut relay, and/or ACC cut relay, then go to step 30 .
Remove starter cut relay 1 (A) and starter cut relay 2 (B) from the under-dash relay block A.
Test starter cut relay land starter cut relay 2 (see «POWER RELAY TEST»(/acura/mdx/ii-2010-2013/remont/body-electrical/#relays__power-relay-test) ). Are the relays OK? YES -Go to step 19. NO -Replace starter cut relay 1 and/or starter cut relay 2, then go to step 24 .
Jump the SCS line with the HDS.
Disconnect PCM connector A (49P).
Turn the ignition switch to ON (II).
Measure the voltage between PCM connector terminal A3 and body ground. Is there 1.0 V or more? YES -Repair a short to power in the wire between the PCM (A3) and starter cut relay 1 or starter cut relay 2, then go to step 23. NO -Go to step 29 .
Turn the ignition switch to LOCK (0).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P16BF indicated? YES -Check for poor connections or loose terminals at starter cut relay 1, starter cut relay 2, and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Turn the ignition switch to LOCK (0).
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P16BF indicated? YES -Check for poor connections or loose terminals at starter cut relay 1, starter cut relay 2, and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P2183: ECT Sensor 2 Circuit Range/Performance Problem

Check for poor connections or loose terminals at ECT sensor 1 and ECT sensor 2. Are the connections and terminals OK? YES -Go to step 2. NO -Repair the connections or terminals, then go to step 21 .
Turn the ignition switch to ON (II).
Check for Pending or Confirmed DTCs with the HDS. Are DTC P1116 and P2183 indicated at the same time? YES -Go to step 12 . NO -Go to step 4.
Start the engine, and let it idle for 10 minutes.
Check ECT SENSOR 2 in the DATA LIST with the HDS. Is about 116 °F (47 °C) or less indicated? YES -Replace ECT sensor 2 (see «ECT SENSOR 2 REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ), then go to step 21 . NO -Go to step 6.
Turn the ignition switch to LOCK (0).
Allow ECT sensor 2 to cool to the ambient temperature.
Note the ambient temperature.
Turn the ignition switch to ON (II).
Quickly note the value of ECT SENSOR 2 quickly in the DATA LIST with the HDS.
Compare the value of ECT SENSOR 2 and the ambient temperature. Does ECT SENSOR 2 differ 5.4 °F (3 °C) or more from the ambient temperature? YES -Replace ECT sensor 2 (see «ECT SENSOR 2 REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ), then go to step 21 . NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at ECT sensor 1, ECT sensor 2, and the PCM.
Start the engine, and let it idle for 10 minutes.
Check ECT SENSOR 1 in the DATA LIST with the HDS. Is about 109 °F (43 °C) or less indicated? YES -Replace ECT sensor 1 (see «ECT SENSOR 1 REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ), then go to step 21 . NO -Go to step 14.
Check ECT SENSOR 2 in the DATA LIST with the HDS. Is about 109 °F (43 °C) or less indicated? YES -Replace ECT sensor 2 (see «ECT SENSOR 2 REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ), then go to step 21 . NO -Go to step 15.
Turn the ignition switch to LOCK (0).
Allow the sensors to cool to the ambient temperature.
Note the ambient temperature.
Turn the ignition switch to ON (II).
Quickly note the value of ECT SENSOR 1 and ECT SENSOR 2 quickly in the DATA LIST with the HDS.
Compare the value of ECT SENSOR 1 and the ambient temperature, and the value of ECT SENSOR 2 and the ambient temperature individually. Does one of the sensors differ more than 5.4 °F (3 °C) from the ambient temperature? YES -Replace the sensor that differed more than 5.4 °F (3 °C) from the ambient temperature, then go to step 21. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at ECT sensor 1, ECT sensor 2, and the PCM.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2183 indicated? YES -Check for poor connections or loose terminals at ECT sensor 1, ECT sensor 2, and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P2184: ECT Sensor 2 Circuit Low Voltage

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 111

Scheme 111: DTC P2184: ECT Sensor 2 Circuit Low Voltage

Turn the ignition switch to ON (II).
Check ECT SENSOR 2 in the DATA LIST with the HDS. Is about 356 °F (180 °C) or more, or 0.08 V or less indicated? YES -Go to step 3. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at ECT sensor 2 and the PCM.
Turn the ignition switch to LOCK (0).
Disconnect the ECT sensor 2 2P connector.
Turn the ignition switch to ON (II).
Check ECT SENSOR 2 in the DATA LIST with the HDS. Is about 356 °F (180 °C) or more, or 0.08 V or less indicated? YES -Go to step 7. NO -Go to step 11 .
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connector A (49P).
Check for continuity between ECT sensor 2 2P connector terminal No. 1 and body ground. Is there continuity? YES -Repair a short in the wire between ECT sensor 2 and the PCM (A21), then go to step 13 . NO -Go to step 18 .
Turn the ignition switch to LOCK (0).
Replace ECT sensor 2 (see «ECT SENSOR 2 REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2184 indicated? YES -Check for poor connections or loose terminals at ECT sensor 2 and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2184 indicated? YES -Check for poor connections or loose terminals at ECT sensor 2 and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P2185: ECT Sensor 2 Circuit High Voltage

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 112

Scheme 112: DTC P2185: ECT Sensor 2 Circuit High Voltage

Scheme 113

Scheme 114

Scheme 115

Turn the ignition switch to ON (II).
Check ECT SENSOR 2 in the DATA LIST with the HDS. Is about -40 °F (-40 °C) or less, or 4.92 V or more indicated? YES -Go to step 3. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at ECT sensor 2 and the PCM.
Turn the ignition switch to LOCK (0).
Disconnect the ECT sensor 2 2P connector.
Connect ECT sensor 2 2P connector terminals No. 1 and No. 2 with a jumper wire.
Turn the ignition switch to ON (II).
Check ECT SENSOR 2 in the DATA LIST with the HDS. Is about -40 °F (-40 °C) or less, or 4.92 V or more indicated? YES -Go to step 8. NO -Go to step 20 .
Turn the ignition switch to LOCK (0).
Remove the jumper wire from the ECT sensor 2 2P connector.
Turn the ignition switch to ON (II).
Measure the voltage between ECT sensor 2 2P connector terminal No. 1 and body ground. Is there about 5 V? YES -Go to step 12. NO -Go to step 16 .
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connector A (49P).
Check for continuity between PCM connector terminal A27 and ECT sensor 2 2P connector terminal No. 2. Is there continuity? YES -Go to step 27 . NO -Repair an open in the wire between the PCM (A27) and ECT sensor 2, then go to step 22 .
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connector A (49P).
Check for continuity between PCM connector terminal A21 and ECT sensor 2 2P connector terminal No. 1. Is there continuity? YES -Go to step 27 . NO -Repair an open in the wire between the PCM (A21) and ECT sensor 2, then go to step 22 .
Turn the ignition switch to LOCK (0).
Replace ECT sensor 2 (see «ECT SENSOR 2 REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2185 indicated? YES -Check for poor connections or loose terminals at ECT sensor 2 and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2185 indicated? YES -Check for poor connections or loose terminals at ECT sensor 2 and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P2195: Rear A/F Sensor (Bank 1, Sensor 1) Signal Stuck Lean; DTC P2197: Front A/F Sensor (Bank 2, Sensor 1) Signal Stuck Lean

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ). Information marked with an asterisk (*) applies to the front bank (Bank 2). If the vehicle was out of fuel and the engine stalled before this DTC was stored, refuel, and clear the DTC with the HDS. If DTC P2101, P2118, P2135, P2138, P2176, or a combination of P2122 and P2127, P2122 and P2138 or P2127 and P2138 are stored at the same time as DTC P2195 (P2197)*, troubleshoot those DTCs first, then recheck for DTC P2195 (P2197)*.

Check for dirt or debris in the MAF sensor/IAT sensor. Is it dirty? YES -Remove the debris. If needed, replace the MAF sensor/IAT sensor (see «MAF SENSOR/IAT SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) ). NO -Go to step 2.
Check the installation of the A/F sensor (Sensor 1). Is the A/F sensor loose or disconnected from the exhaust pipe? YES -Go to step 7 . NO -Go to step 3.
Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine, and let it idle for 2 minutes.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2195 and/or P2197* indicated? YES -Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM, then go to step 14 . NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Turn the ignition switch to LOCK (0).
Reinstall the A/F sensor (Sensor 1) (see «A/F SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__af-sensor-replacement) ).
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2195 and/or P2197* indicated? YES -Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM, then go to step 1 . NO -Go to step 13.
Monitor the OBD STATUS for DTC P2195 and/or P2197* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 12 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM, then go to step 1 . If the HDS indicates NOT COMPLETED, keep idling until a result comes on.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Start the engine, and let it idle for 2 minutes.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2195 and/or P2197* indicated? YES -Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 15 . If the PCM was substituted, go to step 1 . NO -Go to step 17.
Monitor the OBD STATUS for DTC P2195 and/or P2197* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs were indicated in step 16 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), go to step 15 . If the PCM was substituted, go to step 1 . If the HDS indicates NOT COMPLETED, keep idling until a result comes on.

DTC P2227: BARO Sensor Circuit Range/Performance Problem

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ). If DTC P0107, P0108, P1128, and/or P1129 are stored at the same time as DTC P2227, troubleshoot those DTCs first, then recheck for DTC P2227.

Turn the ignition switch to ON (II), and wait 2 seconds.
Check the BARO SENSOR in the DATA LIST with the HDS. Is about 101 kPa (29.9 inHg, 760 mmHg), or about 2.9 V at sea level indicated? YES -Go to step 3. NO -Go to step 7 .
Clear the DTC with the HDS.
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
Test-drive under these conditions: Engine coolant temperature (ECT SENSOR 1) above 158°F (70°C) Transmission in D Throttle position between 13 deg and 26 deg for at least 3 seconds
Monitor the OBD STATUS for DTC P2227 in the DTCs MENU with the HDS. Does the HDS indicate FAILED? YES -Go to step 7. NO -If the HDS indicates PASSED, intermittent failure, the system is OK at this time. If the HDS indicates NOT COMPLETED, go to step 4 and recheck.
Check the intake air system for clogging or restriction (foreign material, dirty air cleaner element, etc). Is the intake air system clogged or restricted? YES -Remove the clog or restriction, then go to step 9 . NO -Go to step 8.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
Test-drive under these conditions: Engine coolant temperature (ECT SENSOR 1) above 158°F (70°C) Transmission in D Throttle position between 13 deg and 26 deg for at least 3 seconds
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2227 indicated? YES -Check for poor connections or loose terminals at the PCM. If the PCM was updated, substitute a known-good PCM, then go to step 9 . If the PCM was substituted, go to step 1 . NO -Go to step 12.
Monitor the OBD STATUS for DTC P2227 in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs were indicated in step 11 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 9 . If the PCM was substituted, go to step 1 . If the HDS indicates NOT COMPLETED, go to step 9 .

DTC P2228: BARO Sensor Circuit Low Voltage

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ). Check the label on the PCM to see if it was made by Keihin or Continental. Refer to the General Troubleshooting Information for more details (see LEARN PROCEDURE (WITHOUT THE HDS) ).

Turn the ignition switch to ON (II).
Check the BARO SENSOR in the DATA LIST with the HDS. Is about 43 kPa (12.7 inHg, 323 mmHg), or 1.31 V or less indicated? (Keihin PCM). Is about 35 kPa (10.3 inHg, 260 mmHg), or 1.08 V or less indicated? (Continental PCM). YES -Go to step 3. NO -Intermittent failure, the system is OK at this time.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2228 indicated? YES -Check for poor connections or loose terminals at the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P2229: BARO Sensor Circuit High Voltage

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ). Check the label on the PCM to see if it was made by Keihin or Continental. Refer to the General Troubleshooting Information for more details (see LEARN PROCEDURE (WITHOUT THE HDS) ).

Turn the ignition switch to ON (II).
Check the BARO SENSOR in the DATA LIST with the HDS. Is about 160 kPa (47.2 inHg, 1, 200 mmHg), or 4.49 V or more indicated? (Keihin PCM). Is about 120 kPa (35.4 inHg, 900 mmHg), or 4.95 V or more indicated? (Continental PCM). YES -Go to step 3. NO -Intermittent failure, the system is OK at this time.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2229 indicated? YES -Check for poor connections or loose terminals at the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P2237: Rear A/F Sensor (Bank 1, Sensor 1) IP Circuit High Voltage; DTC P2240: Front A/F Sensor (Bank 2, Sensor 1) IP Circuit High Voltage

Scheme 116

Scheme 116: DTC P2237: Rear A/F Sensor (Bank 1, Sensor 1) IP Circuit High Voltage; DTC P2240: Front A/F Sensor (

Scheme 117

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle 2 minutes.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2237 and/or P2240* indicated? YES -Go to step 5. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM.
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect the A/F sensor (Sensor 1) 6P connector.
Disconnect PCM connector B (49P).
Check for continuity between A/F sensor (Sensor 1) 6P connector terminal No. 5 to and PCM connector terminal B31 (B32)*. Is there continuity? YES -Go to step 10. NO -Repair an open in the wire between the PCM (B31 (B32)') and the A/F sensor (Sensor 1), then go to step 15 .
Reconnect PCM connector B (49P).
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle 2 minutes.
Measure the voltage between A/F sensor (Sensor 1) 6P connector terminal No. 5 and body ground. Is there about 0.2 V or less? YES -Go to step 21 . NO -Go to step 13.
Turn the ignition switch to LOCK (0).
Replace the A/F sensor (Sensor 1) (see «A/F SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__af-sensor-replacement) ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2237 and/or P2240* indicated? YES -Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM, then go to step 1 . NO -Go to step 20.
Monitor the OBD STATUS for DTC P2237 and/or P2240* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 19 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM, then go to step 1 . If the HDS indicates NOT COMPLETED, keep idling until a result comes on.
Turn the ignition switch to LOCK (0).
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Start the engine, and let it idle.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2237 and/or P2240* Indicated? YES -Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 24 . If the PCM was substituted, go to step 1 . NO -Go to step 26.
Monitor the OBD STATUS for DTC P2237 and/or P2240* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs were indicated in step 25 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 24 . If the PCM was substituted, go to step 1 . If the HDS indicates NOT COMPLETED, keep idling until a result comes on.

DTC P2238: Rear A/F Sensor (Bank 1, Sensor 1) IP Circuit Low Voltage; DTC P2241: Front A/F Sensor (Bank 2, Sensor 1) IP Circuit Low Voltage

Scheme 118

Scheme 118: DTC P2238: Rear A/F Sensor (Bank 1, Sensor 1) IP Circuit Low Voltage; DTC P2241: Front A/F Sensor (B

Scheme 119

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle 2 minutes.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2238 and/or P2241* indicated? YES -Go to step 5. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM.
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect the A/F sensor (Sensor 1) 6P connector.
Disconnect PCM connector B (49P).
Check for continuity between PCM connector terminal B31 (B32)* and body ground. Is there continuity? YES -Repair a short in the wire between the PCM (B31 (B32)*) and the A/F sensor (Sensor 1), then go to step 15 . NO -Go to step 10.
Reconnect PCM connector B (49P).
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle 2 minutes.
Measure the voltage between A/F sensor (Sensor 1) 6P connector terminal No. 5 and body ground. Is there about 0.2 V or less? YES -Go to step 21 . NO -Go to step 13.
Turn the ignition switch to LOCK (0).
Replace the A/F sensor (Sensor 1) (see «A/F SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__af-sensor-replacement) ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2238 and/or P2241* indicated? YES -Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM, then go to step 1 . NO -Go to step 20.
Monitor the OBD STATUS for DTC P2238 and/or P2241* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 19 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM, then go to step 1 . If the HDS indicates NOT COMPLETED, keep idling until a result comes on.
Turn the ignition switch to LOCK (0).
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Start the engine, and let it idle.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2238 and/or P2241* indicated? YES -Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 24 . If the PCM was substituted, go to step 1 . NO -Go to step 26.
Monitor the OBD STATUS for DTC P2238 and/or P2241* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs were indicated in step 25 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 24 . If the PCM was substituted, go to step 1 . If the HDS indicates NOT COMPLETED, keep idling until a result comes on.

DTC P2243: Rear A/F Sensor (Bank 1, Sensor 1) VCENT Circuit High Voltage; DTC P2247: Front A/F Sensor (Bank 2, Sensor 1) VCENT Circuit High Voltage

Scheme 120

Scheme 120: DTC P2243: Rear A/F Sensor (Bank 1, Sensor 1) VCENT Circuit High Voltage; DTC P2247: Front A/F Senso

Scheme 121

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle 2 minutes.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2243 and/or P2247* indicated? YES -Go to step 5. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM.
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect the A/F sensor (Sensor 1) 6P connector.
Disconnect PCM connector B (49P).
Check for continuity between A/F sensor (Sensor 1) 8P connector terminal No. 6 and PCM connector terminal B15(B24)*. Is there continuity? YES -Go to step 10. NO -Repair an open in the wire between the PCM (B15 (B24)*) and the A/F sensor (Sensor 1), then go to step 15 .
Reconnect PCM connector B (49P).
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle 2 minutes.
Measure the voltage between A/F sensor (Sensor 1) 6P connector terminal No. 6 and body ground. Is there about 0.2 V or less? YES -Go to step 21 . NO -Go to step 13.
Turn the ignition switch to LOCK (0).
Replace the A/F sensor (Sensor 1) (see «A/F SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__af-sensor-replacement) ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2243 and/or P2247* indicated? YES -Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM, then go to step 1 . NO -Go to step 20.
Monitor the OBD STATUS for DTC P2243 and/or P2247* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 19 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM, then go to step 1 . If the HDS indicates NOT COMPLETED, keep idling until a result comes on.
Turn the ignition switch to LOCK (0).
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Start the engine, and let it idle.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2243 and/or P2247* indicated? YES -Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 24 . If the PCM was substituted, go to step 1 . NO -Go to step 26.
Monitor the OBD STATUS for DTC P2243 and/or P2247* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs were indicated in step 25 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 24 . If the PCM was substituted, go to step 1 . If the HDS indicates NOT COMPLETED, keep idling until a result comes on.

DTC P2245: Rear A/F Sensor (Bank 1, Sensor 1) VCENT Circuit Low Voltage; DTC P2249: Front A/F Sensor (Bank 2, Sensor 1) VCENT Circuit Low Voltage

Scheme 122

Scheme 122: DTC P2245: Rear A/F Sensor (Bank 1, Sensor 1) VCENT Circuit Low Voltage; DTC P2249: Front A/F Sensor

Scheme 123

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle 2 minutes.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2245 and/or P2249* indicated? YES -Go to step 5. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM.
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect the A/F sensor (Sensor 1) 6P connector.
Disconnect PCM connector B (49P).
Check for continuity between PCM connector terminal B15 (B24)* and body ground. Is there continuity? YES -Repair a short in the wire between the PCM (B15 (B24)*) and the A/F sensor (Sensor 1), then go to step 15 . NO -Go to step 10.
Reconnect PCM connector B (49P).
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle 2 minutes.
Measure the voltage between A/F sensor (Sensor 1) 6P connector terminal No. 6 and body ground. Is there about 0.2 V or less? YES -Go to step 21 . NO -Go to step 13.
Turn the ignition switch to LOCK (0).
Replace the A/F sensor (Sensor 1) (see «A/F SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__af-sensor-replacement) ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2245 and/or P2249* indicated? YES -Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM, then go to step 1 . NO -Go to step 20.
Monitor the OBD STATUS for DTC P2245 and/or P2249* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 19 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM, then go to step 1 . If the HDS indicates NOT COMPLETED, keep idling until a result comes on.
Turn the ignition switch to LOCK (0).
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Start the engine, and let it idle.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2245 and/or P2249* indicated? YES -Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 24 . If the PCM was substituted, go to step 1 . NO -Go to step 26.
Monitor the OBD STATUS for DTC P2245 and/or P2249* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs were indicated in step 25 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 24 . If the PCM was substituted, go to step 1 . If the HDS indicates NOT COMPLETED, keep idling until a result comes on.

DTC P2251: Rear A/F Sensor (Bank 1, Sensor 1) VS Circuit High Voltage; DTC P2254: Front A/F Sensor (Bank 2, Sensor 1) VS Circuit High Voltage

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ). If DTC P2251 and/or P2254* is stored at the same time as DTC P0134 and/or P0154*, troubleshoot DTC P2251 and/or P2254* first, then recheck for P0134 and/or P0154*. Information marked with an asterisk (*) applies to the front bank (Bank 2).

Scheme 124

Scheme 124: DTC P2251: Rear A/F Sensor (Bank 1, Sensor 1) VS Circuit High Voltage; DTC P2254: Front A/F Sensor (

Scheme 125

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle 2 minutes.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2251 and/or P2254* indicated? YES -Go to step 5. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM.
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect the A/F sensor (Sensor 1) 6P connector.
Disconnect PCM connector B (49P).
Check for continuity between A/F sensor (Sensor 1) 6P connector terminal No. 4 and PCM connector terminal B13 (B14)*. Is there continuity? YES -Go to step 10. NO -Repair an open in the wire between the PCM (B13 (B14)*) and the A/F sensor (Sensor 1), then go to step 15 .
Reconnect PCM connector B (49P).
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle 2 minutes.
Measure the voltage between A/F sensor (Sensor 1) 6P connector terminal No. 4 and body ground. Is there about 0.2 V or less? YES -Go to step 21 . NO -Go to step 13.
Turn the ignition switch to LOCK (0).
Replace the A/F sensor (Sensor 1) (see «A/F SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__af-sensor-replacement) ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2251 and/or P2254* indicated? YES -Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM, then go to step 1 . NO -Go to step 20.
Monitor the OBD STATUS for DTC P2251 and/or P2254* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 19 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM, then go to step 1 . If the HDS indicates NOT COMPLETED, keep idling until a result comes on.
Turn the ignition switch to LOCK (0).
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Start the engine, and let it idle.
Check for Pending or Confirmed DTCs with the HDS. If DTC P2251 and/or P2254* indicated? YES -Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 24 . If the PCM was substituted, go to step 1 . NO -Go to step 26.
Monitor the OBD STATUS for DTC P2251 and/or P2254* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs were indicated in step 25 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 24 . If the PCM was substituted, go to step 1 . If the HDS indicates NOT COMPLETED, keep idling until a result comes on.

DTC P2252: Rear A/F Sensor (Bank 1, Sensor 1) VS Circuit Low Voltage; DTC P2255: Front A/F Sensor (Bank 2, Sensor 1) VS Circuit Low Voltage

Scheme 126

Scheme 126: DTC P2252: Rear A/F Sensor (Bank 1, Sensor 1) VS Circuit Low Voltage; DTC P2255: Front A/F Sensor (B

Scheme 127

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle 2 minutes.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2252 and/or P2255* indicated? YES -Go to step 5. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM.
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect the A/F sensor (Sensor 1) 6P connector.
Disconnect PCM connector B (49P).
Check for continuity between PCM connector terminal B13 (B14)* and body ground. Is there continuity? YES -Repair a short in the wire between the PCM (B13 (B14)*) and the A/F sensor (Sensor 1), then go to step 15 . NO -Go to step 10.
Reconnect PCM connector B (49P).
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle 2 minutes.
Measure the voltage between A/F sensor (Sensor 1) 6P connector terminal No. 4 and body ground. Is there about 0.2 V or less? YES -Go to step 21 . NO -Go to step 13.
Turn the ignition switch to LOCK (0).
Replace the A/F sensor (Sensor 1) (see «A/F SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__af-sensor-replacement) ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the H DS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2252 and/or P2255* indicated? YES -Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM, then go to step 1 . NO -Go to step 20.
Monitor the OBD STATUS for DTC P2252 and/or P2255* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 19 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM, then go to step 1 . If the HDS indicates NOT COMPLETED, keep idling until a result comes on.
Turn the ignition switch to LOCK (0).
Reconnect all connectors.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Start the engine, and let it idle.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2252 and/or P2255* indicated? YES -Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 24 . If the PCM was substituted, go to step 1 . NO -Go to step 26.
Monitor the OBD STATUS for DTC P2252 and/or P2255* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs were indicated in step 25 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then go to step 24 . If the PCM was substituted, go to step 1 . If the HDS indicates NOT COMPLETED, keep idling until a result comes on.

DTC P2270: Rear Secondary HO2S (Bank 1, Sensor 2) Circuit Signal Stuck Lean; DTC P2272: Front Secondary HO2S (Bank 2, Sensor 2) Circuit Signal Stuck Lean

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
Test-drive under these conditions: Engine coolant temperature (ECT SENSOR 1) above 158°F (70°C) Transmission in D Engine speed between 1, 500-3, 000 rpm Drive 35 seconds or more
Monitor the OBD STATUS for DTC P2270 and/or P2272* in the DTCs MENU with the HDS. Does the HDS indicate FAILED? YES -Go to step 6. NO -If the HDS indicates PASSED, intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM. If the HDS indicates EXECUTING, keep driving until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 3 and recheck.
Turn the ignition switch to LOCK (0).
Replace the secondary HO2S (Sensor 2) (see «SECONDARY HO2S REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__secondary-ho2s-replacement) ).
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
Test-drive under these conditions: Engine coolant temperature (ECT SENSOR 1) above 158°F (70°C) Transmission in D Engine speed between 1, 500-3, 000 rpm Drive 35 seconds or more
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2270 and/or P2272* indicated? YES -Check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM, then go to step 1 . NO -Go to step 14.
Monitor the OBD STATUS for DTC P2270 and/or P2272* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 13 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM, then go to step 1 . If the HDS indicates EXECUTING, keep driving until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 12 .

DTC P2610: PCM Ignition Off Internal Timer Malfunction

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2610 indicated? YES -Go to step 4. NO -Intermittent failure, the system is OK at this time. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2610 indicated? YES -If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC P2A00: Rear A/F Sensor (Bank 1, Sensor 1) Circuit Range/Performance Problem; DTC P2A03: Front A/F Sensor (Bank 2, Sensor 1) Circuit Range/Performance Problem

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
Test-drive under these conditions: Engine coolant temperature (ECT SENSOR 1) above 158°F (70°C) Transmission in D Vehicle speed between 25-55 mph (40-88 km/h) for 5 minutes. Drive at a steady speed between 55-75 mph (88-120 km/h) for 10 seconds, then decelerate (with the throttle fully closed) for 6 seconds.
Monitor the OBD STATUS for DTC P2A00 and/or P2A03* in the DTCs MENU with the HDS. Does the HDS indicate FAILED? YES -Go to step 6. NO -If the HDS indicates PASSED, intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM. If it is EXECUTING, keep driving until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 3 and recheck.
Turn the ignition switch to LOCK (0).
Replace the A/F sensor (Sensor 1) (see «A/F SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__af-sensor-replacement) ).
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Test-drive under these conditions: Engine coolant temperature (ECT SENSOR 1) above 158°F (70°C) Transmission in D Vehicle speed between 25-55 mph (40-88 km/h) for 5 minutes. Drive at a steady speed between 55-75 mph (88-120 km/h) for 10 seconds, then decelerate (with the throttle fully closed) for 6 seconds.
Check for Pending or Confirmed DTCs with the HDS. Is DTC P2A00 and/or P2A03* indicated? YES -Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM, then go to step 1 . NO -Go to step 13.
Monitor the OBD STATUS for DTC P2A00 and/or P2A03* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 12 , go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM, then go to step 1 . If the HDS indicates EXECUTING, keep driving until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 11 .

DTC U0029: F-CAN A Malfunction (BUS-OFF (PCM))

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Check for Pending or Confirmed DTCs with the HDS. Is DTC U0029 indicated? YES -Go to step 4. NO -Intermittent failure, the system is OK at this time.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC U0029 indicated? YES -If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC U0047: F-CAN B Malfunction (BUS-OFF (PCM))

Note. For vehicles without the adaptive cruise control (ACC) - if this DTC is stored, do not try to repair the vehicle. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Check for Pending or Confirmed DTCs with the HDS. Is DTC U0047 indicated? YES -Go to step 4. NO -Intermittent failure, the system is OK at this time. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .
Watch the adaptive cruise control (ACC) indicator. Does the ACC indicator (amber) stay on? YES -Check for ACC system DTC, and do the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO -Go to step 5.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC U0047 indicated? YES -Check for poor connections or loose terminals at the ACC unit and the PCM. If the PCM was updated, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the PCM was substituted, go to step 1 . NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC U0104: F-CAN A Malfunction (PCM-Adaptive Cruise Control (ACC) Unit)

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 128

Scheme 128: DTC U0104: F-CAN A Malfunction (PCM-Adaptive Cruise Control (ACC) Unit)

Scheme 129

Turn the ignition switch to ON (II).
Check for Pending or Confirmed DTCs with the HDS. Are DTC U0029 and U0104 Indicated at the same time? YES -Go to the troubleshooting for DTC U0029 (see «DTC U0029: F-CAN A Malfunction (BUS-OFF (PCM))»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__dtc-u0029-f-can-a-malfunction-bus-off) ). NO -Go to step 3.
Clear the DTC with the HDS.
Check for Pending or Confirmed DTCs with the HDS. Is DTC U0104 indicated? YES -Go to step 5. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the ACC unit and the PCM.
Check for communication to the DRIVING SUPPORT SYSTEM with the HDS Does the HDS communicate with the ACC unit? YES -Go to step 6. NO -Go to the «DLC CIRCUIT TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__dlc-circuit-troubleshooting)
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect the ACC unit 20P connector.
Disconnect PCM connector A (49P).
Check for continuity between PCM connector terminal A48 and ACC unit 20P connector terminal No. 10. Is there continuity? YES -Go to step 11. NO -Repair an open in the wire between the PCM (A48) and the ACC unit, then go to step 12 .
Check for continuity between PCM connector terminal A49 and ACC unit 20P connector terminal No. 20. Is there continuity? YES -Substitute a known-good ACC unit (see «ADAPTIVE CRUISE CONTROL (ACC) UNIT REMOVAL/INSTALLATION»(/acura/mdx/ii-2010-2013/remont/cruise-control-systems/#adaptive-cruise-control-acc) ), then go to step 12 and recheck. If DTC U0104 is not indicated after substitution, replace the original ACC unit (see «ADAPTIVE CRUISE CONTROL (ACC) UNIT REMOVAL/INSTALLATION»(/acura/mdx/ii-2010-2013/remont/cruise-control-systems/#adaptive-cruise-control-acc) ), then go to step 12. NO -Repair an open in the wire between the PCM (A49) and the ACC unit, then go to step 12.
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC U0104 indicated? YES -Check for poor connections or loose terminals at the ACC unit and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC U0114: F-CAN A Malfunction (PCM-SH-AWD Control Unit)

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 130

Scheme 130: DTC U0114: F-CAN A Malfunction (PCM-SH-AWD Control Unit)

Scheme 131

Turn the ignition switch to ON (II).
Check for Pending or Confirmed DTCs with the HDS. Are DTC U0029 and U0114 indicated at the same time? YES -Go to troubleshooting for DTC U0029 (see «DTC U0029: F-CAN A Malfunction (BUS-OFF (PCM))»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__dtc-u0029-f-can-a-malfunction-bus-off) ). NO -Go to step 3.
Clear the DTC with the HDS.
Check for Pending or Confirmed DTCs with the HDS. Is DTC U0114 indicated? YES -Go to step 5. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the SH-AWD control unit and the PCM.
Check for communication to the SH-AWD system with the HDS. Does the HDS communicate with the SH-AWD control unit? YES -Go to step 6. NO -Go to the SH-AWD symptom troubleshooting for SH-AWD indicator does not go off, and no DTCs are stored (see «DTC 91-1: SH-AWD CONTROL UNIT PROGRAMMING ERROR»(/acura/mdx/ii-2010-2013/remont/differentials-drive-axles/#rear-differential__dtc-91-1-sh-awd-control-unit-programming) ).
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect SH-AWD control unit connector A (20P).
Disconnect PCM connector A (49P).
Check for continuity between PCM connector terminal A48 and SH-AWD control unit connector A (20P) terminal No. 10. Is there continuity? YES -Go to step 11. NO -Repair an open in the wire between the PCM (A48) and the SH-AWD control unit, then go to step 12 .
Check for continuity between PCM connector terminal A49 and SH-AWD control unit connector A (20P) terminal No. 20. Is there continuity? YES -Update the SH-AWD control unit if it does not have the latest software (see «SH-AWD® CONTROL UNIT UPDATE»(/acura/mdx/ii-2010-2013/remont/differentials-drive-axles/#rear-differential) ), or substitute a known-good SH-AWD control unit (see «SH-AWD® CONTROL UNIT REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/differentials-drive-axles/#rear-differential) ), then go to step 12 and recheck. If DTC U0114 is not indicated after substitution, replace the original SH-AWD control unit (see «SH-AWD® CONTROL UNIT REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/differentials-drive-axles/#rear-differential) ), then go to step 12. NO -Repair an open in the wire between the PCM (A49) and the SH-AWD control unit, then go to step 12.
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC U0114 indicated? YES -Check for poor connections or loose terminals at the SH-AWD control unit and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC U0122: F-CAN A Malfunction (PCM-VSA Modulator-Control Unit)

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 132

Scheme 132: DTC U0122: F-CAN A Malfunction (PCM-VSA Modulator-Control Unit)

Scheme 133

Turn the ignition switch to ON (II).
Check for Pending or Confirmed DTCs with the HDS. Are DTC U0029 and U0122 indicated at the same time? YES -Go to troubleshooting for DTC U0029 (see «DTC U0029: F-CAN A Malfunction (BUS-OFF (PCM))»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__dtc-u0029-f-can-a-malfunction-bus-off) ). NO -Go to step 3.
Clear the DTC with the HDS.
Check for Pending or Confirmed DTCs with the HDS. Is DTC U0122 indicated? YES -Go to step 5. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the VSA modulator-control unit and the PCM.
Check for communication to the VSA with the HDS. Does the HDS communicate with the VSA modulator-control unit? YES -Go to step 6. NO -Go to the VSA symptom troubleshooting for the ABS indicator, the brake system indicator, and the VSA indicator that will not go off (see «ABS INDICATOR, BRAKE SYSTEM INDICATOR, VSA INDICATOR, AND TRAILER STABILITY ASSIST WARNING DO NOT GO OFF»(/acura/mdx/ii-2010-2013/remont/anti-locktraction-control/#vsa-system-components) ).
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect the VSA modulator-control unit 46P connector.
Disconnect PCM connector A (49P).
Check for continuity between PCM connector terminal A48 and VSA modulator-control unit 46P connector terminal No. 39. Is there continuity? YES -Go to step 11. NO -Repair an open in the wire between the PCM (A48) and the VSA modulator-control unit, then go to step 12 .
Check for continuity between PCM connector terminal A49 and VSA modulator-control unit 46P connector terminal No. 38. Is there continuity? YES -Update the VSA modulator-control unit if it does not have the latest software (see «VSA MODULATOR-CONTROL UNIT UPDATE»(/acura/mdx/ii-2010-2013/remont/anti-locktraction-control/#vsa-system-components__vsa-modulator-control-unit-update) ), or substitute a known-good VSA modulator-control unit (see «VSA MODULATOR-CONTROL UNIT REMOVAL AND INSTALLATION»(/acura/mdx/ii-2010-2013/remont/anti-locktraction-control/#vsa-system-components__vsa-modulator-control-unit-removal-and-installation) ), then go to step 12 and recheck. If DTC U0122 is not indicated after substitution, replace the original VSA modulator-control unit (see «VSA MODULATOR-CONTROL UNIT REMOVAL AND INSTALLATION»(/acura/mdx/ii-2010-2013/remont/anti-locktraction-control/#vsa-system-components__vsa-modulator-control-unit-removal-and-installation) ), then go to step 12. NO -Repair an open in the wire between the PCM (A49) and the VSA modulator-control unit, then go to step 12.
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC U0122 indicated? YES -Check for poor connections or loose terminals at the VSA modulator-control unit and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

DTC U0155: F-CAN A Malfunction (PCM-Gauge Control Module)

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 134

Scheme 134: DTC U0155: F-CAN A Malfunction (PCM-Gauge Control Module)

Scheme 135

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Check for Pending or Confirmed DTCs with the HDS. Is DTC U0155 indicated? YES -Go to step 4. NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the gauge control module and the PCM.
Check for body electrical DTCs in the DTCs MENU with the HDS. Is DTC B1168, B1169, and/or B1178 indicated? YES -Go to step 5. NO -Do the gauge control module input test (see «GAUGE CONTROL MODULE INPUT TEST»(/acura/mdx/ii-2010-2013/remont/gauges-instrument-panels/#gauges__gauge-control-module-input-test) ).
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Remove the gauge control module (see «GAUGE CONTROL MODULE REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/gauges-instrument-panels/#gauges__gauge-control-module-replacement) ).
Disconnect gauge control module connector A (12P).
Disconnect PCM connector A (49P).
Check for continuity between PCM connector terminal A48 and gauge control module connector A (12P) terminal No. 12. Is there continuity? YES -Go to step 11. NO -Repair an open in the wire between the PCM (A48) and the gauge control module, then go to step 12 .
Check for continuity between PCM connector terminal A49 and gauge control module connector A (12P) terminal No. 6. Is there continuity? YES -Substitute a known-good gauge control module (see «GAUGE CONTROL MODULE REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/gauges-instrument-panels/#gauges__gauge-control-module-replacement) ), then go to step 12 and recheck. If DTC U0155 is not indicated, replace the original gauge control module (see «GAUGE CONTROL MODULE REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/gauges-instrument-panels/#gauges__gauge-control-module-replacement) ), then go to step 12. NO -Repair an open in the wire between the PCM (A49) and the gauge control module, then go to step 12.
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC U0155 indicated? YES -Check for poor connections or loose terminals at the gauge control module and the PCM, then go to step 1 . NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

Do the PCM update procedure for the PGM-FI and A/T systems (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ).
Check for Pending or Confirmed DTCs with the HDS. Is DTC U0300 indicated? YES -Replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) .

Scheme 136

Scheme 136: F-CAN Circuit Troubleshooting

Scheme 137

Scheme 138

Scheme 139

Scheme 140

Scheme 141

Scheme 142

Scheme 143

Scheme 144

Scheme 145

Scheme 146

Scheme 147

Scheme 148

Scheme 149

Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connector A (49P).
Measure the resistance between PCM connector terminals A48 and A49, then compare your reading to the model/trim level listed the table below. VEHICLES WITH ACTIVE DAMPER Other Systems Resistance Adaptive cruise control (ACC) (USA model) About 44-55 ohms Adaptive cruise control (ACC) (Canada model) About 45-56 ohms VEHICLES WITHOUT ACTIVE DAMPER Other Systems Resistance Adaptive cruise control (ACC) (USA model) About 46-57 ohms Adaptive cruise control (ACC) (Canada model) About 46-57 ohms Without adaptive cruise control (ACC) About 48-59 ohms Is the resistance OK? YES -Go to step 20 . NO -Go to step 5.
Disconnect these connectors: Gauge control module connector A (12P) (see «GAUGE CONTROL MODULE REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/gauges-instrument-panels/#gauges__gauge-control-module-replacement) ). VSA modulator-control unit 46P connector (see «VSA MODULATOR-CONTROL UNIT REMOVAL AND INSTALLATION»(/acura/mdx/ii-2010-2013/remont/anti-locktraction-control/#vsa-system-components__vsa-modulator-control-unit-removal-and-installation) ). Yaw rate-lateral/longitudinal acceleration sensor 4P connector (see «YAW RATE-LATERAL/LONGITUDINAL ACCELERATION SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/anti-locktraction-control/#vsa-system-components__yaw-rate-laterallongitudinal-acceleration-sensor-replacement) ). Steering angle sensor 5P connector (see «STEERING ANGLE SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/anti-locktraction-control/#vsa-system-components__steering-angle-sensor-replacement) ). SRS unit connector A (39P) (see «SRS UNIT REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/airbag/#srs-supplemental-restraint-system) ). TPMS control unit 20P connector (see «TPMS CONTROL UNIT REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/wheel-tire-system/#tpms-tire-pressure-monitoring-system__tpms-control-unit-replacement) ). Active damper control unit connector B (14P) (with active damper) (see «ACTIVE DAMPER CONTROL UNIT REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/wheel-tire-system/#active-damper-system) ). SH-AWD control unit connector A (20P) (see «SH-AWD® CONTROL UNIT REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/differentials-drive-axles/#rear-differential) ). ACC unit 20P connector (with ACC) (see «ADAPTIVE CRUISE CONTROL (ACC) UNIT REMOVAL/INSTALLATION»(/acura/mdx/ii-2010-2013/remont/cruise-control-systems/#adaptive-cruise-control-acc) ). E-pretensioner unit connector B (14P) (with ACC) (see «E-PRETENSIONER UNIT REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/airbag/#srs-supplemental-restraint-system) ). AcuraLink control unit connector A (32P) (USA model with AcuraLink) (see «ACURALINK CONTROL UNIT (XM RECEIVER) REMOVAL/INSTALLATION»(/acura/mdx/ii-2010-2013/remont/entertainment-systems/#audio-system) ).
Check for continuity between PCM connector terminals A48 and A49. Is there continuity? YES -Repair a short in the wires between PCM connector terminals A48 and A49. NO -Go to step 7.
Check for continuity between PCM connector terminal A48 and gauge control module connector A (12P) terminal No. 12. Is there continuity? YES -Go to step 8. NO -Repair an open in the wire between the PCM (A48) and the gauge control module.
Check for continuity between PCM connector terminal A48 and VSA modulator-control unit 46P connector terminal No. 39. Is there continuity? YES -Go to step 9. NO -Repair an open in the wire between the PCM (A48) and the VSA modulator-control unit.
Check for continuity between PCM connector terminal A48 and SH-AWD control unit connector A (20P) terminal No. 10. Is there continuity? YES - With ACC: Go to step 10. Without ACC: Go to step 11 . NO -Repair an open in the wire between the PCM (A48) and the SH-AWD control unit.
Check for continuity between PCM connector terminal A48 and ACC unit 20P connector terminal No. 10. Is there continuity? YES -Go to step 11. NO -Repair an open in the wire between the PCM (A48) and the ACC unit.
Check for continuity between PCM connector terminal A49 and gauge control module connector A (12P) terminal No. 6. Is there continuity? YES -Go to step 12. NO -Repair an open in the wire between the PCM (A49) and the gauge control module.
Check for continuity between PCM connector terminal A49 and VSA modulator-control unit 46P connector terminal No. 38. Is there continuity? YES -Go to step 13. NO -Repair an open in the wire between the PCM (A49) and the VSA modulator-control unit.
Check for continuity between PCM connector terminal A49 and SH-AWD control unit connector A (20P) terminal No. 20. Is there continuity? YES - With ACC: Go to step 14. Without ACC: Go to step 15 . NO -Repair an open in the wire between the PCM (A49) and the SH-AWD control unit.
Check for continuity between PCM connector terminal A49 and ACC unit 20P connector terminal No. 20. Is there continuity? YES -Go to step 15. NO -Repair an open in the wire between the PCM (A49) and the ACC unit.
Reconnect the VSA modulator-control unit 46P connector.
Measure the resistance between PCM connector terminals A48 and A49. Is there about 108-132 ohms? YES -Go to step 17. NO -Substitute a known-good VSA modulator-control unit (see «VSA MODULATOR-CONTROL UNIT REMOVAL AND INSTALLATION»(/acura/mdx/ii-2010-2013/remont/anti-locktraction-control/#vsa-system-components__vsa-modulator-control-unit-removal-and-installation) ), then reconnect PCM connector A. If the HDS identifies the vehicle, replace the original VSA modulator-control unit (see «VSA MODULATOR-CONTROL UNIT REMOVAL AND INSTALLATION»(/acura/mdx/ii-2010-2013/remont/anti-locktraction-control/#vsa-system-components__vsa-modulator-control-unit-removal-and-installation) ).
Disconnect the VSA modulator-control unit 46P connector.
Reconnect SH-AWD control unit connector A (20P).
Measure the resistance between PCM connector terminals A48 and A49. Is there about 108-132 ohms? YES -Go to step 20. NO -Substitute a known-good SH-AWD control unit (see «SH-AWD® CONTROL UNIT REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/differentials-drive-axles/#rear-differential) ), then reconnect PCM connector A. If the HDS identifies the vehicle, replace the original SH-AWD control unit (see «SH-AWD® CONTROL UNIT REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/differentials-drive-axles/#rear-differential) ).
Disconnect these connectors: Gauge control module connector A (12P) (see «GAUGE CONTROL MODULE REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/gauges-instrument-panels/#gauges__gauge-control-module-replacement) ). VSA modulator-control unit 46P connector (see «VSA MODULATOR-CONTROL UNIT REMOVAL AND INSTALLATION»(/acura/mdx/ii-2010-2013/remont/anti-locktraction-control/#vsa-system-components__vsa-modulator-control-unit-removal-and-installation) ). Yaw rate-lateral/longitudinal acceleration sensor 4P connector (see «YAW RATE-LATERAL/LONGITUDINAL ACCELERATION SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/anti-locktraction-control/#vsa-system-components__yaw-rate-laterallongitudinal-acceleration-sensor-replacement) ). Steering angle sensor 5P connector (see «STEERING ANGLE SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/anti-locktraction-control/#vsa-system-components__steering-angle-sensor-replacement) ). SRS unit connector A (39P) (see «SRS UNIT REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/airbag/#srs-supplemental-restraint-system) ). TPMS control unit 20P connector (see «TPMS CONTROL UNIT REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/wheel-tire-system/#tpms-tire-pressure-monitoring-system__tpms-control-unit-replacement) ). Active damper control unit connector B (14P) (with active damper) (see «ACTIVE DAMPER CONTROL UNIT REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/wheel-tire-system/#active-damper-system) ). SH-AWD control unit connector A (20P) (see «SH-AWD® CONTROL UNIT REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/differentials-drive-axles/#rear-differential) ). ACC unit 20P connector (with ACC) (see «ADAPTIVE CRUISE CONTROL (ACC) UNIT REMOVAL/INSTALLATION»(/acura/mdx/ii-2010-2013/remont/cruise-control-systems/#adaptive-cruise-control-acc) ). E-pretensioner unit connector B (14P) (with ACC) (see «E-PRETENSIONER UNIT REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/airbag/#srs-supplemental-restraint-system) ). AcuraLink control unit connector A (32P) (USA model with AcuraLink) (see «ACURALINK CONTROL UNIT (XM RECEIVER) REMOVAL/INSTALLATION»(/acura/mdx/ii-2010-2013/remont/entertainment-systems/#audio-system) ).
Check for continuity between PCM connector terminal A48 and body ground. Is there continuity? YES -Repair a short in the wire between the PCM (A48) and the gauge control module, the VSA modulator-control unit, the SRS unit, the TPMS control unit, the yaw rate-lateral/longitudinal acceleration sensor, the steering angle sensor, the SH-AWD control unit, the active damper control unit (with active damper), the AcuraLink control unit (with AcuraLink), the ACC unit (with ACC), the E-pretensioner unit (with ACC), or the DLC. NO -Go to step 22.
Check for continuity between PCM connector terminal A49 and body ground. Is there continuity? YES -Repair a short in the wire between the PCM (A49) and the gauge control module, the VSA modulator-control unit, the SRS unit, the TPMS control unit, the yaw rate-lateral/longitudinal acceleration sensor, the steering angle sensor, the SH-AWD control unit, the active damper control unit (with active damper), the AcuraLink control unit (with AcuraLink), the ACC unit (with ACC), the E-pretensioner unit (ACC), or the DLC. NO -Go to step 23.
Reconnect all connectors.
Connect the HDS to the DLC (see «GENERAL TROUBLESHOOTING INFORMATION»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems) ).
Disconnect gauge control module connector A (12P).
Turn the ignition switch to ON (II), and read the HDS. Does the HDS identify the vehicle? YES -Replace the gauge control module (see «GAUGE CONTROL MODULE REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/gauges-instrument-panels/#gauges__gauge-control-module-replacement) ). NO -Go to step 27.
Turn the ignition switch to LOCK (0).
Reconnect gauge control module connector A (12P).
Disconnect the VSA modulator-control unit 46P connector.
Turn the ignition switch to ON (II), and read the HDS. Does the HDS identify the vehicle? YES -Replace the VSA modulator-control unit (see «VSA MODULATOR-CONTROL UNIT REMOVAL AND INSTALLATION»(/acura/mdx/ii-2010-2013/remont/anti-locktraction-control/#vsa-system-components__vsa-modulator-control-unit-removal-and-installation) ). NO -Go to step 31.
Turn the ignition switch to LOCK (0).
Reconnect the VSA modulator-control unit 46P connector.
Disconnect SRS unit connector A (39P).
Turn the ignition switch to ON (II), and read the HDS. Does the HDS identify the vehicle? YES -Replace the SRS unit (see «SRS UNIT REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/airbag/#srs-supplemental-restraint-system) ). NO -Go to step 35.
Turn the ignition switch to LOCK (0).
Reconnect SRS unit connector A (39P).
Disconnect the TPMS control unit 20P connector.
Turn the ignition switch to ON (II), and read the HDS. Does the HDS identify the vehicle? YES -Replace TPMS control unit (see «TPMS CONTROL UNIT REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/wheel-tire-system/#tpms-tire-pressure-monitoring-system__tpms-control-unit-replacement) ). NO -Go to step 39.
Turn the ignition switch to LOCK (0).
Reconnect the TPMS control unit 20P connector.
Disconnect the yaw rate-lateral/longitudinal acceleration sensor 4P connector.
Turn the ignition switch to ON (II), and read the HDS. Does the HDS identify the vehicle? YES -Replace the yaw rate-lateral/longitudinal acceleration sensor (see «YAW RATE-LATERAL/LONGITUDINAL ACCELERATION SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/anti-locktraction-control/#vsa-system-components__yaw-rate-laterallongitudinal-acceleration-sensor-replacement) ). NO -Go to step 43.
Turn the ignition switch to LOCK (0).
Reconnect the yaw rate-lateral/longitudinal acceleration sensor 4P connector.
Disconnect the steering angle sensor 5P connector.
Turn the ignition switch to ON (II), and read the HDS. Does the HDS identify the vehicle? YES -Replace the steering angle sensor (see «STEERING ANGLE SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/anti-locktraction-control/#vsa-system-components__steering-angle-sensor-replacement) ). NO - With active damper: Go to step 47. Without active damper: Go to step 51 .
Turn the ignition switch to LOCK (0).
Reconnect the steering angle sensor 5P connector.
Disconnect active damper control unit connector B (14P).
Turn the ignition switch to ON (II), and read the HDS. Does the HDS identify the vehicle? YES -Replace the active damper control unit (see «ACTIVE DAMPER CONTROL UNIT REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/wheel-tire-system/#active-damper-system) ). NO -Go to step 51.
Turn the ignition switch to LOCK 0).
Reconnect the steering angle sensor 5P connector or active damper control unit connector B (14P).
Disconnect SH-AWD control unit connector A (20P)
Turn the ignition switch to ON (II), and read the HDS. Does the HDS identify the vehicle? YES -Replace the SH-AWD control unit (see «SH-AWD® CONTROL UNIT REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/differentials-drive-axles/#rear-differential) ). NO - With ACC: Go to step 55. Without ACC: Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the HDS identifies the vehicle with a known-good PCM, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ).
Turn the ignition switch to LOCK (0).
Reconnect SH-AWD control unit connector A (20P).
Disconnect the ACC unit 20P connector.
Turn the ignition switch to ON (II), and read the HDS. Does the HDS identify the vehicle? YES -Replace the ACC unit (see «ADAPTIVE CRUISE CONTROL (ACC) UNIT REMOVAL/INSTALLATION»(/acura/mdx/ii-2010-2013/remont/cruise-control-systems/#adaptive-cruise-control-acc) ). NO -Go to step 59.
Turn the ignition switch to LOCK (0).
Reconnect the ACC unit 20P connector.
Disconnect E-pretensioner unit connector B (14P).
Turn the ignition switch to ON (II), and read the HDS. Does the HDS identify the vehicle? YES -Replace the E-pretensioner unit (see «E-PRETENSIONER UNIT REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/airbag/#srs-supplemental-restraint-system) ). NO - With AcuraLink: Go to step 63. Without AcuraLink: Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the HDS identifies the vehicle with a known-good PCM, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ).
Turn the ignition switch to LOCK (0).
Reconnect E-pretensioner unit connector B (14P).
Disconnect AcuraLink control unit connector A (32P).
Turn the ignition switch to ON (II), and read the HDS. Does the HDS identify the vehicle? YES -Replace the AcuraLink control unit (see «ACURALINK CONTROL UNIT (XM RECEIVER) REMOVAL/INSTALLATION»(/acura/mdx/ii-2010-2013/remont/entertainment-systems/#audio-system) ). NO -Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the HDS identifies the vehicle with a known-good PCM, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ).

Scheme 150

Scheme 150: MIL Circuit Troubleshooting

Turn the ignition switch to ON (II).
Do the gauge control module self-diagnostic function (see «SELF-DIAGNOSTIC FUNCTION»(/acura/mdx/ii-2010-2013/remont/gauges-instrument-panels/#gauges__self-diagnostic-function) ). Does the MIL indicator flash? YES -Go to step 3. NO -Substitute a known-good gauge control module (see «GAUGE CONTROL MODULE REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/gauges-instrument-panels/#gauges__gauge-control-module-replacement) ), then recheck. If the symptom/indication goes away with a known-good gauge control module, replace the original gauge control module (see «GAUGE CONTROL MODULE REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/gauges-instrument-panels/#gauges__gauge-control-module-replacement) ).
Connect the HDS to the DLC (see «GENERAL TROUBLESHOOTING INFORMATION»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems) ).
Check the SCS in the DATA LIST with the HDS. Is a short indicated? YES -Go to step 5. NO -Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the symptom/indication goes away and the PCM was updated, troubleshooting is complete. If the symptom/indication goes away and the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ).
Turn the ignition switch to LOCK (0).
Disconnect PCM connector A (49P), then disconnect the HDS.
Check for continuity between PCM connector terminal A32 and body ground. Is there continuity? YES -Repair a short in the wire between the PCM (A32), the Headlight leveling control unit (with headlight leveling control), and the DLC. NO -Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a, known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the symptom/indication goes away and the PCM was updated, troubleshooting is complete. If the symptom/indication goes away and the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ).

DLC Circuit Troubleshooting

Note. If you suspect the HDS or the HDS DLC cable may be the source of the communication problem, verify that they are working properly by connecting them to a known-good, like vehicle and system, and checking for communication problems.

Scheme 151

Scheme 151: DLC Circuit Troubleshooting

Scheme 152

Scheme 153

Scheme 154

Scheme 155

Scheme 156

Scheme 157

Scheme 158

Scheme 159

Scheme 160

Scheme 161

Scheme 162

Scheme 163

Scheme 164

Scheme 165

Scheme 166

Scheme 167

Scheme 168

Scheme 169

Scheme 170

Scheme 171

Scheme 172

Scheme 173

Turn the ignition switch to LOCK (0).
Connect the HDS to the DLC (see «GENERAL TROUBLESHOOTING INFORMATION»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems) ).
Turn the ignition switch to ON (II), and read the HDS. Does the HDS identify the vehicle? YES -Go to step 4. NO -Go to step 27 .
Check for Pending or Confirmed DTCs in the PGM-FI system with the HDS. Are any Pending or Confirmed DTCs indicated? YES -Go to the indicated «DTC'S TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) . NO - If the HDS does not communicate with the SRS, go to step 5. If the HDS does not communicate with the VSA system, go to step 7 . If the HDS does not communicate with the IMMOBI (immobilizer) system, go to step 9 . If the HDS does not communicate with the SH-AWD system, go to step 11 . If the HDS does not communicate with the TPMS, go to step 13 . If the HDS does not communicate with the active damper system, go to step 15 . If the HDS does not communicate with the ACC system, go to step 17 . If the HDS does not communicate with the BODY ELECTRICAL system, go to step 19 .
Turn the ignition switch to LOCK (0).
Turn the ignition switch to ON (II), and watch the SRS indicator. Does the SRS indicator come on and go off? YES -Go to step 21 . NO -Go to the SRS symptom troubleshooting for an SRS indicator that stays on with no stored DTCs (see «SRS INDICATOR STAYS ON, BUT NO DTCS ARE STORED, OR CANNOT BE READ»(/acura/mdx/ii-2010-2013/remont/airbag/#srs-supplemental-restraint-system__srs-indicator-stays-on-but-no) ).
Turn the ignition switch to LOCK (0).
Turn the ignition switch to ON (II), and watch the VSA indicator. Does the VSA indicator come on and go off? YES -Go to step 21 . NO -Go to the VSA symptom troubleshooting for an ABS indicator, brake system indicator, and VSA indicator that do not go off (see «ABS INDICATOR, BRAKE SYSTEM INDICATOR, VSA INDICATOR, AND TRAILER STABILITY ASSIST WARNING DO NOT GO OFF»(/acura/mdx/ii-2010-2013/remont/anti-locktraction-control/#vsa-system-components) ).
Turn the ignition switch to LOCK (0).
Turn the ignition switch to ON (II), and watch the immobilizer indicator. Does the immobilizer indicator stay on or flash? YES -Go to the immobilizer system's troubleshooting (see «SYMPTOM TROUBLESHOOTING INFORMATION»(/acura/mdx/ii-2010-2013/remont/door-locks-anti-theft-systems/#immobilizer-system) ). NO -Go to step 21 .
Turn the ignition switch to LOCK (0).
Turn the ignition switch to ON (II), and watch the SH-AWD indicator. Does the SH-AWD indicator come on and go off? YES -Go to step 21 . NO -Go to the SH-AWD symptom troubleshooting for an SH-AWD indicator that does not go off with no stored DTCs (see «DTC 91-1: SH-AWD CONTROL UNIT PROGRAMMING ERROR»(/acura/mdx/ii-2010-2013/remont/differentials-drive-axles/#rear-differential__dtc-91-1-sh-awd-control-unit-programming) ).
Turn the ignition switch to LOCK (0).
Turn the ignition switch to ON (II), and watch the TPMS indicator. Does the TPMS indicator come on and go off? YES -Go to step 21 . NO -Go to the TPMS symptom troubleshooting for a TPMS indicator that does not go off with no stored DTCs (see «TPMS INDICATOR DOES NOT GO OFF, AND NO DTCS ARE STORED»(/acura/mdx/ii-2010-2013/remont/wheel-tire-system/#tpms-tire-pressure-monitoring-system__tpms-indicator-does-not-go-off) ).
Turn the ignition switch to LOCK(0).
Turn the ignition switch to ON (II), and watch the active damper system indicator. Does the active damper system indicator come on and go off? YES -Go to step 21 . NO -Go to the active damper system symptom troubleshooting for an active damper system indicator that does not go off with no stored DTCs (see «SYMPTOM TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/wheel-tire-system/#active-damper-system) ).
Turn the ignition switch to LOCK (0).
Turn the ignition switch to ON (II), and watch the ACC indicator. Does the ACC Indicator come on and go off? YES -Go to step 19. NO -Go to the ACC symptom troubleshooting for an ACC indicator that does not go off (see «ADAPTIVE CRUISE CONTROL (ACC) INDICATOR (AMBER) DOES NOT GO OFF»(/acura/mdx/ii-2010-2013/remont/cruise-control-systems/#adaptive-cruise-control-acc) ).
Do the gauge control module self-diagnostic function (see «SELF-DIAGNOSTIC FUNCTION»(/acura/mdx/ii-2010-2013/remont/gauges-instrument-panels/#gauges__self-diagnostic-function) ).
Check the gauge display. Is B-CAN....ERROR indicated? YES -Check for B-CAN system DTCs (see «TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE 1 AND TEST MODE 2 (WITHOUT THE HDS)»(/acura/mdx/ii-2010-2013/remont/communication-devices/#multiplex-integrated-control-system__troubleshooting-b-can-system-diagnosis-test) ). NO -Go to step 21.
Turn the ignition switch to LOCK (0), then do the battery terminal disconnection procedure (see «USING THE GR8 BATTERY DIAGNOSTIC STATION»(/acura/mdx/ii-2010-2013/remont/body-electrical/#battery) ), and wait at least 3 minutes before continuing.
Disconnect the HDS from the DLC.
Check for continuity between DLC terminal No. 7 and body ground. Is there continuity? YES -Go to step 24. NO -Go to step 25 .
Continue to check for continuity between DLC terminal No. 7 and body ground, while disconnecting these connectors, one at a time: SRS unit connector A (39P) VSA modulator-control unit 46P connector Immobilizer-keyless control unit 7P connector Audio unit connector A (17P) (without navigation) SH-AWD control unit connector A (20P) Active damper control unit connector B (14P) (with active damper) TPMS control unit 20P connector Audio-navigation unit connector A (24P) (with navigation) ACC unit 20P connector (with ACC) MICU connector P (30P) Does continuity go away when one of the above parts is disconnected? YES -Replace the part that caused an open when it was disconnected. NO -Repair a short in the wire between the DLC (K-line) and the SRS unit, the VSA modulator-control unit, the immobilizer-keyless control unit, the audio unit, the SH-AWD control unit, the active damper control unit, the TPMS control unit, the ACC unit, the audio-navigation unit, or the MICU.
Connect DLC terminal No. 7 to body ground with a jumper wire.
Check for continuity between body ground and these connector terminals: Connector Terminal SRS unit connector A (39P) No. 18 (ORN) VSA modulator-control unit 46P connector No. 15 (ORN) Immobilizer-keyless control unit 7P connector No. 5 (ORN) Audio unit connector A (17P) No. 6 (ORN) SH-AWD control unit connector A (20P) No. 5 (ORN) Active damper control unit connector B (14P) No. 3 (ORN) TPMS control unit 20P connector No. 7 (ORN) MICU connector P (30P) No. 6 (ORN) ACC unit 20P connector No. 8 (ORN) Audio-navigation unit connector A (24P) No. 3 (ORN) Is there continuity between the DLC terminal and each of the terminals in the chart? YES -Replace the part that does not communicate with the HDS. NO -Repair an open in the wire between the DLC (K-line) and the appropriate connector.
Check for B-CAN system DTCs without the HDS (see «GENERAL TROUBLESHOOTING INFORMATION»(/acura/mdx/ii-2010-2013/remont/communication-devices/#multiplex-integrated-control-system) ). Is DTC B1168, B1169, and/or B1178 indicated? YES -Go to step 38 . NO -Go to step 28.
Turn the ignition switch to LOCK (0).
Disconnect the HDS from the DLC.
Measure the voltage between DLC terminal No. 16 and body ground. Is there battery voltage? YES -Go to step 31. NO -Repair an open in the wire between DLC terminal No. 16 and the No. 7 BACK UP (10 A) fuse in the under-dash fuse/relay box.
Measure the voltage between DLC terminals No. 4 and No. 16. Is there battery voltage? YES -Go to step 32. NO -Repair an open in the wire between DLC terminal No. 4 and G503.
Connect the HDS to the DLC (see «GENERAL TROUBLESHOOTING INFORMATION»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems) ).
Jump the SCS line with the HDS.
Disconnect PCM connector A (49P).
Disconnect the HDS from the DLC.
Check for continuity between PCM connector terminal A48 and DLC terminal No. 6. Is there continuity? YES -Go to step 37. NO -Repair an open in the wire between the PCM (A48) and DLC terminal No. 6.
Check for continuity between PCM connector terminal A49 and DLC terminal No. 14. Is there continuity? YES -Reconnect all connectors, then update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the symptom/indication goes away and the PCM was updated, troubleshooting is complete. If the symptom/indication goes away and the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). NO -Repair an open in the wire between the PCM (A49) and DLC terminal No. 14.
Try to start the engine. Does the engine start and idle smoothly? YES -Go to «F-CAN CIRCUIT TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system) NO -Go to step 39.
Turn the ignition switch to LOCK (0).
Check the No. 3 IG1 MAIN (50 A) fuse in the main under-hood fuse box. Is the fuse OK? YES -Repair an open in the wire between the No. 3 IG1 MAIN (50 A) fuse and the ignition switch. If the wire is OK, go to step 41. NO -Repair a short in the wire between the No. 3 IG1 MAIN (50 A) fuse and the main under-hood fuse box. Also replace the No. 3 IG1 MAIN (50 A) fuse.
Inspect the No. 8 IGP (15 A) fuse in the under-hood fuse/relay box. Is the fuse OK? YES -Go to step 48 . NO -Go to step 42.
Remove the blown No. 8 IGP (15 A) fuse from the under-hood fuse/relay box.
Jump the SCS line with the HDS.
Disconnect PCM connector B (49P).
While disconnecting each of the parts or connectors below, one at a time, check for continuity between PCM connector terminal B3 and body ground. PGM-FI main relay 2 Each injector 2P connector Camshaft position (CMP) sensor 3P connector Crankshaft position (CKP) sensor 3P connector MAF sensor/IAT sensor 5P connector Under-hood fuse/relay box connector H (9P) Does continuity go away when one of the above parts is disconnected? YES -Replace the part that made the short to body ground go away when disconnected. Reconnect all connectors, then update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the symptom/indication goes away and the PCM was updated, troubleshooting is complete. If the symptom/indication goes away and the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). Also replace the No. 8 IGP (15 A) fuse. NO -Go to step 46.
Disconnect these parts or connectors: PGM-FI main relay 2 Each injector 2P connector Camshaft position (CMP) sensor 3P connector Crankshaft position (CKP) sensor 3P connector MAF sensor/IAT sensor 5P connector Under-hood fuse/relay box connector H (9P)
Check for continuity between PCM connector terminal B3 and body ground. Is there continuity? YES -Repair a short in the wire between the PCM (B3) and each part. Also replace the No. 8 IGP (15 A) fuse. NO -Replace the under-hood fuse/relay box. Also replace the No. 8 IGP (15A) fuse.
Inspect the No. 19 FUEL PUMP (20 A) fuse in the under-dash fuse/relay box. Is the fuse OK? YES -Go to step 60 . NO -Go to step 49.
Remove the blown No. 19 FUEL PUMP (20 A) fuse from the under-dash fuse/relay box.
Remove the left kick panel (see «TRIM REMOVAL/INSTALLATION - DOOR AREAS»(/acura/mdx/ii-2010-2013/remont/exteriorinterior-trim/#interior-trim__trim-removalinstallation-door-areas) ), then remove PGM-FI main relay 2 (G) from the under-dash fuse/relay box.
Test PGM-FI main relay 2 (see «POWER RELAY TEST»(/acura/mdx/ii-2010-2013/remont/body-electrical/#relays__power-relay-test) ). Is the relay OK? YES -Go to step 52. NO -Replace PGM-FI main relay 2. Also replace the No. 19 FUEL PUMP (20 A) fuse.
Check for continuity between PGM-FI main relay 2 4P connector terminal No. 1 and body ground. Is there continuity? YES -Go to step 53. NO -Go to step 56 .
Jump the SCS line with the HDS.
Disconnect PCM connector B (49P).
Check for continuity between PCM connector terminal B42 and body ground. Is there continuity? YES -Repair a short in the wire between the No. 19 FUEL PUMP (20 A) fuse and the PCM (B42), between the No. 19 FUEL PUMP (20 A) fuse and PGM-FI main relay 2, or between the No. 19 FUEL PUMP (20 A) fuse and the immobilizer control unit. Also replace the No. 19 FUEL PUMP (20 A) fuse. NO -Replace the No. 19 FUEL PUMP (20 A) fuse in the under-dash fuse/relay box, reconnect all connectors, and update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the symptom/indication goes away and the PCM was updated, troubleshooting is complete. If the symptom/indication goes away and the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ).
Remove the cargo floor lid (see «TRIM REMOVAL/INSTALLATION - CARGO AREA»(/acura/mdx/ii-2010-2013/remont/exteriorinterior-trim/#interior-trim__trim-removalinstallation-cargo-area) ).
On models with active damper, remove the active damper control unit (see «ACTIVE DAMPER CONTROL UNIT REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/wheel-tire-system/#active-damper-system) ).
Disconnect the fuel pump control module 10P connector.
Check for continuity between fuel pump control module 10P connector terminal No. 3 and body ground. Is there continuity? YES -Repair a short in the wire between the fuel pump control module and PGM-FI main relay 2. Also replace the No. 19 FUEL PUMP (20 A) fuse in the under-dash fuse/relay box. NO -Replace the No. 19 FUEL PUMP (20 A) fuse, then substitute a known-good fuel pump control module (see «FUEL PUMP CONTROL MODULE REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/fuel-system/#fuel-supply-system) ), and recheck. If the symptom/indication goes away with a known-good fuel pump control module, replace the original fuel pump control module (see «FUEL PUMP CONTROL MODULE REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/fuel-system/#fuel-supply-system) ).
Jump the SCS line with the HDS.
Disconnect PCM connectors A (49P) and B (49P).
Turn the ignition switch to ON (II).
Measure the voltage between PCM connector terminal B42 and body ground. Is there battery voltage? YES -Go to step 64. NO -Repair an open in the wire between the No. 19 FUEL PUMP (20 A) fuse and the PCM (B42).
Measure the voltage between PCM connector terminal A6 and body ground. Is there battery voltage? YES -Go to step 68 . NO -Go to step 65.
Turn the ignition switch to LOCK (0).
Disconnect under-hood fuse/relay box connector E (14P).
Check for continuity between PCM connector terminal A6 and under-hood fuse/relay box connector E (14P) terminal No. 5. Is there continuity? YES -Test PGM-FI main relay 1 (built into the relay control module) (see «RELAY CONTROL MODULE TEST»(/acura/mdx/ii-2010-2013/remont/body-electrical/#relays__relay-control-module-test) ). If PGM-FI main relay 1 is OK, reconnect all connectors, then update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the symptom/indication goes away and the PCM was updated, troubleshooting is complete. If the symptom/indication goes away and the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). NO -Repair an open in the wire between the PCM (A6) and the under-hood fuse/relay box.
Turn the ignition switch to LOCK (0).
Disconnect under-hood fuse/relay box connector H (9P).
Check for continuity between PCM connector terminal B3 and under-hood fuse/relay box connector H (9P) terminal No. 1. Is there continuity? YES -Go to step 71. NO -Repair an open in the wire between the PCM (B3) and the under-hood fuse/relay box.
Test PGM-FI main relay 1 (built into the relay control module) (see «RELAY CONTROL MODULE TEST»(/acura/mdx/ii-2010-2013/remont/body-electrical/#relays__relay-control-module-test) ). Is PGM-FI main relay 1 OK? YES -Go to step 72. NO -Replace the under-hood fuse/relay box (see «DTC B1065: RELAY CONTROL MODULE LOST COMMUNICATION WITH DRIVER'S MPCS UNIT (DRLOCKSW MESSAGE)»(/acura/mdx/ii-2010-2013/remont/fuses-circuit-breakers/#under-hood-fuserelay-box__dtc-b1065-relay-control-module-lost) ).
Disconnect PCM connector C (49P).
Check for continuity between body ground and PCM connector terminals B1, B40, B41, C1, and C41 individually. Is there continuity? YES -Go to step 74. NO -Repair an open in the wire between the PCM (B1, B40, B41, C1, C41) and body ground (G101).
Check for continuity between PCM connector terminal B36 and body ground. Is there continuity? YES -Go to step 75. NO -Go to step 76 .
Continue to check for continuity between PCM connector terminal B36 and body ground, while disconnecting these parts, one at a time: MAP sensor 3P connector Output shaft (countershaft) speed sensor 3P connector Does continuity go away when one of the above parts is disconnected? YES -Replace the part that caused an open when it was disconnected. NO -Repair a short in the wire between the PCM (B36) and the MAP sensor or the output shaft (countershaft) speed sensor.
Check for continuity between PCM connector terminal C12 and body ground. Is there continuity? YES -Go to step 77. NO -Go to step 78 .
Continue to check for continuity between PCM connector terminal C12 and body ground, while disconnecting the input shaft (mainshaft) speed sensor 3P connector. Is there continuity? YES -Repair a short in the wire between the PCM (C12) and the input shaft (mainshaft) speed sensor. NO -Replace the input shaft (mainshaft) speed sensor (see «INPUT SHAFT (MAINSHAFT) SPEED SENSOR REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/automatic-trans/#automatic-transmission) ).
Check for continuity between PCM connector terminal A24 and body ground. Is there continuity? YES -Go to step 79. NO -Go to step 80 .
Continue to check for continuity between PCM connector terminal A24 and body ground, while disconnecting the APP sensor 6P connector. Is there continuity? YES -Repair a short in the wire between the PCM (A24) and the APP sensor. NO -Replace the accelerator pedal module (see «ACCELERATOR PEDAL MODULE REMOVAL/INSTALLATION»(/acura/mdx/ii-2010-2013/remont/engine-control-systems/#electronic-throttle-control-system) ).
Check for continuity between PCM connector terminal A25 and body ground. Is there continuity? YES -Go to step 81. NO -Go to step 82 .
Continue to check for continuity between PCM connector terminal A25 and body ground, while disconnecting these connectors one at a time. APP sensor 6P connector FTP sensor 3P connector Does continuity go away when one of the above parts is disconnected? YES -Replace the part that caused an open when it was disconnected. NO -Repair a short in the wire between the PCM (A25) and the APP sensor or the FTP sensor.
Check for continuity between PCM connector terminal B18 and body ground. Is there continuity? YES -Go to step 83. NO -Go to step 84 .
Continue to check for continuity between PCM connector terminal B18 and body ground, while disconnecting the throttle body 6P connector. Is there continuity? YES -Repair a short in the wire between the PCM (B18) and the throttle body. NO -Replace the throttle body (see «THROTTLE BODY REMOVAL/INSTALLATION»(/acura/mdx/ii-2010-2013/remont/mechanical/#intake-air-system__throttle-body-removalinstallation) ).
Check for continuity between PCM connector terminal C11 and body ground. Is there continuity? YES -Go to step 85. NO -Reconnect all connectors, then update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), then recheck. If the symptom/indication goes away and the PCM was updated, troubleshooting is complete. If the symptom/indication goes away and the PCM was substituted, replace the original PCM (see «PCM REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ).
Continue to check for continuity between PCM connector terminal C11 and body ground, while disconnecting these parts, one at a time: IMT actuator 5P connector EGR valve 5P connector Does continuity go away when one of the above parts is disconnected? YES -Replace the part that caused an open when it was disconnected. NO -Repair a short in the wire between the PCM (C11) and the IMT actuator or the EGR valve.

Scheme 174

Scheme 174: Injector Replacement

Scheme 175

Relieve the fuel pressure (see «FUEL PRESSURE RELIEVING»(/acura/mdx/ii-2010-2013/remont/fuel-system/#fuel-supply-system__fuel-pressure-relieving) ).
Remove the intake manifold (see «INTAKE MANIFOLD REMOVAL AND INSTALLATION»(/acura/mdx/ii-2010-2013/remont/mechanical/#intake-manifold-and-exhaust-system) ).
Disconnect the quick-connect fitting (A) (see «FUEL LINE/QUICK-CONNECT FITTING REMOVAL»(/acura/mdx/ii-2010-2013/remont/fuel-system/#fuel-supply-system__fuel-linequick-connect-fitting-removal) ).
Remove the fuel joint hose mounting bolt (B).
Disconnect the connectors (C) from the injectors.
Remove the fuel rail mounting bolts (D) from the fuel rails (E).
Remove the fuel rail and the injectors from the injector base.
Remove the injector clips (F) from the fuel rail.
Remove the injectors from the fuel rails.
Coat the new O-rings (black) (A) with clean engine oil, and insert the injectors (B) into the fuel rails (C).
Install the injector clips (D).
Coat the new injector O-rings (brown) (E) with clean engine oil.
Install the fuel rails and injectors in the injector base (F).
Install the fuel rail mounting bolts, and connect the connectors on the injectors.
Install the fuel joint hose mounting bolt.
Connect the quick-connect fitting (see «FUEL LINE/QUICK-CONNECT FITTING INSTALLATION»(/acura/mdx/ii-2010-2013/remont/fuel-system/#fuel-supply-system__fuel-linequick-connect-fitting-installation) ).
Turn the ignition switch to ON (II), but do not operate the starter. After the fuel pump runs for about 2 seconds, the fuel rail will be pressurized. Repeat this two or three times, then check for fuel leaks.
Install the intake manifold with a new gasket (see «INTAKE MANIFOLD REMOVAL AND INSTALLATION»(/acura/mdx/ii-2010-2013/remont/mechanical/#intake-manifold-and-exhaust-system) ).

Scheme 176

Scheme 176: MAP Sensor Replacement

Remove the engine cover (see step 6 under «ENGINE REMOVAL»(/acura/mdx/ii-2010-2013/remont/mechanical/#engine-assembly__engine-removal) ).
Disconnect the MAP sensor 3P connector (A).
Remove the screw (B).
Remove the MAP sensor (C).
Install the parts in the reverse order of removal with a new O-ring (D).

Scheme 177

Scheme 177: MAF Sensor/IAT Sensor Replacement

Disconnect the MAF sensor/IAT sensor 5P connector (A).
Remove the screws (B).
Remove the MAF sensor/IAT sensor (C).
Install the parts in the reverse order of removal with a new O-ring (D).

Scheme 178

Scheme 178: ECT Sensor 1 Replacement

Drain the engine coolant (see «COOLANT CHECK»(/acura/mdx/ii-2010-2013/remont/cooling-fan/#engine-cooling-system) ).
Remove the engine cover (see step 6 under «ENGINE REMOVAL»(/acura/mdx/ii-2010-2013/remont/mechanical/#engine-assembly__engine-removal) ).
Remove the main under-hood fuse box.
Disconnect the ECT sensor 1 2P connector (A).
Remove ECT sensor 1 (B).
Install the parts in the reverse order of removal with a new O-ring (C), then refill the radiator with engine coolant (see «COOLANT CHECK»(/acura/mdx/ii-2010-2013/remont/cooling-fan/#engine-cooling-system) ).

Scheme 179

Scheme 179: ECT Sensor 2 Replacement

Drain the engine coolant (see «COOLANT CHECK»(/acura/mdx/ii-2010-2013/remont/cooling-fan/#engine-cooling-system) ).
Remove the splash shield (see «SPLASH SHIELD REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/exterior-body-panels/#fenderwell__splash-shield-replacement) ).
Disconnect the ECT sensor 2 2P connector (A).
Remove ECT sensor 2 (B).
Install the parts in the reverse order of removal with a new O-ring (C), then refill the radiator with engine coolant (see «COOLANT CHECK»(/acura/mdx/ii-2010-2013/remont/cooling-fan/#engine-cooling-system) ).

A/F Sensor Replacement

Special Tools Required

O2 Sensor Socket Wrench Snap-on SWR2 or O2 Sensor Wrench Snap-on YA8875, commercially available

Scheme 180

Scheme 180: Front Bank (Bank 2)

Disconnect the front A/F sensor 6P connector (A), then remove the A/F sensor (B).
Install the parts in the reverse order of removal.

Scheme 181

Scheme 181: Rear Bank (Bank 1)

Disconnect the rear A/F sensor 6P connector (A), then remove the rear A/F sensor (B).
Install the parts in the reverse order of removal.

Secondary HO2S Replacement

Special Tools Required

O2 Sensor Socket Wrench Snap-on SWR2 or O2 Sensor Wrench Snap-on YA8875, commercially available

Scheme 182

Scheme 182: Front Bank (Bank2)

Scheme 183

Disconnect the front secondary HO2S 4P connector (A), and remove the harness clamps (B).
Raise the vehicle on a lift.
Remove the harness clamp (A), then remove the front secondary HO2S (B).
Install the parts in the reverse order of removal.

Scheme 184

Scheme 184: Rear Bank (Bank 1)

Raise the vehicle on a lift.
Disconnect the rear secondary HO2S 4P connector (A), and remove the harness clamps (B).
Remove the rear secondary HO2S (C).
Install the parts in the reverse order of removal.

Scheme 185

Scheme 185: CMP Sensor Replacement

Scheme 186

Remove the timing belt (see «TIMING BELT INSPECTION»(/acura/mdx/ii-2010-2013/remont/mechanical/#cylinder-head) ).
Remove the front camshaft pulley (CMP pulse plate) (A).
Disconnect the CMP sensor 3P connector (B), then remove the back cover (C).
Remove the CMP sensor (A) from the back cover.
Install the parts in the reverse order of removal. Install the timing belt (see «TIMING BELT INSTALLATION»(/acura/mdx/ii-2010-2013/remont/mechanical/#cylinder-head__timing-belt-installation) ).
Do the CKP pattern clear/CKP pattern learn procedure (see «HDS CLEAR COMMAND»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__hds-clear-command) ).

Scheme 187

Scheme 187: CKP Sensor Replacement

Raise the vehicle on a lift. NOTE: Make sure the vehicle is level, because engine oil will drip out when you remove the sensor.
Remove the CKP sensor cover (A).
Disconnect the CKP sensor 3P connector (B).
Remove the CKP sensor (C).
Install the parts in the reverse order of removal with a new O-ring (D).
Do the CKP pattern clear/CKP pattern learn procedure (see «HDS CLEAR COMMAND»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__hds-clear-command) ).
Check the engine oil level, and add more oil if needed.

Scheme 188

Scheme 188: Knock Sensor Replacement

Remove the intake manifold (see «INTAKE MANIFOLD REMOVAL AND INSTALLATION»(/acura/mdx/ii-2010-2013/remont/mechanical/#intake-manifold-and-exhaust-system) ).
Remove the injector base (see «INJECTOR BASE REMOVAL AND INSTALLATION»(/acura/mdx/ii-2010-2013/remont/mechanical/#intake-manifold-and-exhaust-system) ).
Disconnect the knock sensor 1P connector (A).
Remove the knock sensor (B).
Install the parts in the reverse order of removal.

PCM Update

Special Tools Required

Honda Diagnostic System (HDS) tablet tester
Honda Interface Module (HIM) and an iN workstation with the latest HDS software version
HDS pocket tester
GNA600 and an iN workstation with the latest HDS software version
MVCI unit with the latest control module (CM) update software installed

Any one of the above updating tools can be used.

Note. Make sure the HDS/iN workstation or the MVCI has the latest HDS software version. Before you update the PCM, make sure the battery in the vehicle is fully charged, and connect a jumper battery (not a battery charger) to maintain system voltage. Never turn the ignition switch to ACC (I) or to LOCK(0) during the update. If there is a problem with the update, leave the ignition switch is ON (II). To prevent PCM damage, do not operate anything electrical (headlights, audio system, brakes, A/C, power windows, door locks, etc.) during the update. To ensure the latest program is installed, do a PCM update whenever the PCM is substituted or replaced. You cannot update a PCM with a program it already has. It will only accept a new program. High temperature in the engine compartment might cause the PCM to become too hot to run the update. If the engine has been running before this procedure, open the hood and cool the engine compartment. If you need to diagnose the Honda interface module (HIM) because the HIM's red (#3) light came on or was flashing during the update, leave the ignition switch in ON (II) when you disconnect the HIM from the data link connector (DLC). This will prevents PCM damage.

Scheme 189

Turn the ignition switch to ON (II), but do not start the engine.
Connect the HDS to the data link connector (DLC) (A) located under the driver's side of the dashboard.
Make sure the HDS communicates with the PCM and other vehicle systems. If it doesn't, go to the «DLC CIRCUIT TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__dlc-circuit-troubleshooting) . If you are returning from DLC circuit troubleshooting, skip steps 4 and 5 , and clean the throttle body (see «THROTTLE BODY TEST»(/acura/mdx/ii-2010-2013/remont/mechanical/#intake-air-system) ) after updating the PCM.
Select the INSPECTION MENU with HDS.
Select the ETCS TEST, then select the TP POSITION CHECK, and follow the HDS screen prompts. NOTE: If the TP POSITION CHECK indicates FAILED, continue this procedure.
Exit the HDS, then select the update mode, and follow the screen prompts to update the PCM.
If the software in the PCM is the latest, disconnect the updating tool from the DLC, and go back to the procedure that you were doing. If the software in the PCM is not the latest, follow the instructions on the screen. If prompted to choose the PGM-FI system or the A/T system, make sure you update both. NOTE: If the PCM update system requires you to cool the PCM, follow the instructions on screen. If you run in to a problem during the update procedure (programming takes over 15 minutes, status bar goes over 100 %, D or immobilizer indicator flashes, HDS tablet freezes, etc.), follow these steps to minimize the chance of damaging the PCM: Leave the ignition switch is in ON (II). Connect a jumper battery (do not connect a battery charger). Shut down the HDS. Disconnect the HDS from the DLC. Reboot the HDS. Reconnect the HDS to the DLC, and try the update procedure again.
If the TP POSITION CHECK failed in step 5 , clean the throttle body (see «THROTTLE BODY TEST»(/acura/mdx/ii-2010-2013/remont/mechanical/#intake-air-system) ).
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Do the CKP pattern clear/CKP pattern learn procedure (see «HDS CLEAR COMMAND»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__hds-clear-command) ).

PCM Replacement

Special Tools Required

Honda Diagnostic System (HDS) tablet tester
Honda Interface Module (HIM) and an iN workstation with the latest HDS software version
HDS pocket tester
GNA600 and an iN workstation with the latest HDS software version
MVCI unit with the latest control module (CM) update software installed

Any one of the above updating tools can be used.

Note. Make sure the HDS/iN workstation or the MVCI has the latest HDS software version. If you are replacing the PCM after substituting a known-good PCM, reinstall the original PCM, then do this procedure. During the procedure, if any READ DATA, WRITE DATA, or other data checks fail, note the failure, then continue.

Scheme 190

Scheme 191

Scheme 192

Scheme 193

Connect the HDS to the data link connector (DLC) (A) located under the driver's side of the dashboard.
Turn the ignition switch to ON (II).
Make sure the HDS communicates with the PCM and other vehicle systems. If it doesn't, go to the «DLC CIRCUIT TROUBLESHOOTING»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__dlc-circuit-troubleshooting) . If you are returning from DLC circuit troubleshooting, skip steps 4 through 9 , 20 through 26 , and 29 through 31 , and do this after replacing the PCM; Replace the engine oil (see «OIL PRESSURE TEST»(/acura/mdx/ii-2010-2013/remont/lubrication-system/#engine-lubrication__oil-pressure-test) ) and the engine oil filter (see «ENGINE OIL FILTER REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/lubrication-system/#engine-lubrication__engine-oil-filter-replacement) ). Replace the ATF (see «ATF REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/automatic-trans/#automatic-transmission__atf-replacement) ). Clean the throttle body (see «THROTTLE BODY TEST»(/acura/mdx/ii-2010-2013/remont/mechanical/#intake-air-system) ).
Select the PGM-FI system with the HDS.
Select the INSPECTION MENU with the HDS.
Select the ETCS TEST, then select the TP POSITION CHECK, and follow the screen prompts. NOTE: If the TP POSITION CHECK indicates FAILED, continue with this procedure.
Select the REPLACE PCM MENU, then select READ DATA and follow the screen prompts. NOTE: Doing this step copies (READS) the engine oil life data from the original PCM so you can later download (WRITES) it into the new PCM. If the READ DATA indicates FAILED, continue with this procedure.
Select the A/T system with the HDS.
Select the REPLACE TCM/PCM MENU, then select READ DATA and follow the screen prompts. NOTE: Doing this step copies (READS) the ATF life data from the original PCM so you can later download (WRITES) it into the new PCM. If the READ DATA indicates FAILED, continue with this procedure.
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Remove the auxiliary under-hood fuse/relay box (A) from the stay (B), then remove the bolt (C).
Remove the bracket (D), then free the A/C discharge line (E) from the clip (F) and remove the A/C suction line mounting bracket bolt (G). Keihin PCM Continental PCM
Remove the cover (H), then disconnect PCM connectors A, B, and C. NOTE: PCM connectors A, B, and C have symbols (A=[], B=delta , C=o) embossed on them for identification.
Keihin PCM: Remove the bolts (I), then remove the PCM (J).
Continental PCM: Remove the nuts (K), then remove the PCM (J).
Continental PCM: Remove the spacers (L).
Install the parts in the reverse order of removal.
Turn the ignition switch to ON (II).
Manually input the VIN to the PCM with the HDS. NOTE: DTC P0630 VIN Not Programmed or Mismatch may be stored because the VIN has not been programmed into the PCM; ignore it, and continue this procedure.
If the READ DATA (engine oil life) failed in step 7 , go to step 24 . Otherwise, go to step 22.
Select the PGM-FI system with the HDS.
Select the REPLACE PCM MENU, then select WRITE DATA and follow the screen prompts. NOTE: If the WRITE DATA indicates FAILED, continue with this procedure.
If the READ DATA (ATF life) failed in step 9 , go to step 27 . Otherwise go to step 25.
Select the A/T SYSTEM with the HDS.
Select the REPLACE TCM/PCM MENU, then select WRITE DATA and follow the screen prompts. NOTE: If the WRITE DATA indicates FAILED, continue with this procedure.
Select IMMOBI SYSTEM with the HDS.
Enter the immobilizer PCM code that you got from the iN, and use the PCM replacement procedure in the IMMOBI MENU of the HDS; it allows you to start the engine.
If the TP POSITION CHECK failed in step 6 , clean the throttle body (see «THROTTLE BODY TEST»(/acura/mdx/ii-2010-2013/remont/mechanical/#intake-air-system) ), then go to step 30.
If the READ DATA failed in step 7 or the WRITE DATA failed in step 23 , replace the engine oil (see «OIL PRESSURE TEST»(/acura/mdx/ii-2010-2013/remont/lubrication-system/#engine-lubrication__oil-pressure-test) ) and engine oil filter (see «ENGINE OIL FILTER REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/lubrication-system/#engine-lubrication__engine-oil-filter-replacement) ), then go to step 31.
If the READ DATA failed in step 9 or the WRITE DATA failed in step 26 , replace the ATF (see «ATF REPLACEMENT»(/acura/mdx/ii-2010-2013/remont/automatic-trans/#automatic-transmission__atf-replacement) ), then go to step 32.
Select PGM-FI system and reset the PCM with the HDS.
Update the PCM if it does not have the latest software (see «PCM UPDATE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-update) ).
Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
Do the CKP pattern clear/CKP pattern learn procedure (see «HDS CLEAR COMMAND»(/acura/mdx/ii-2010-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__hds-clear-command) ).

Pgm-Fi System Acura MDX II рестайлинг

Scheme 1

Scheme 2

DTC P0101: MAF Sensor Circuit Range/Performance Problem

DTC P0102: MAF Sensor Circuit Low Voltage

Scheme 3

Scheme 4

Scheme 5

Scheme 6

DTC P0103: MAF Sensor Circuit High Voltage

Scheme 7

Scheme 8

DTC P0107: MAP Sensor Circuit Low Voltage

Scheme 9

Scheme 10

Scheme 11

DTC P0108: MAP Sensor Circuit High Voltage

Scheme 12

Scheme 13

Scheme 14

Scheme 15

DTC P0111: IAT Sensor Circuit Range/Performance Problem

DTC P0112: IAT Sensor Circuit Low Voltage

Scheme 16

DTC P0113: IAT Sensor Circuit High Voltage

Scheme 17

Scheme 18

Scheme 19

Scheme 20

DTC P0116: ECT Sensor 1 Circuit Range/Performance Problem

DTC P0117: ECT Sensor 1 Circuit Low Voltage

Scheme 21

DTC P0118: ECT Sensor 1 Circuit High Voltage

Scheme 22

Scheme 23

Scheme 24

Scheme 25

DTC P0125: ECT Sensor 1 Malfunction/Slow Response

DTC P0128: Cooling System Malfunction

DTC P0133: Rear A/F Sensor (Bank 1, Sensor 1) Malfunction/Slow Response; DTC P0153: Front A/F Sensor (Bank 2, Sensor 1) Malfunction/Slow Response

DTC P0134: Rear A/F Sensor (Bank 1, Sensor 1) Heater System Malfunction; DTC P0154: Front A/F Sensor (Bank 2, Sensor 1) Heater System Malfunction

Scheme 26

Scheme 27

DTC P0135: Rear A/F Sensor (Bank 1, Sensor 1) Heater Circuit Malfunction; DTC P0155: Front A/F Sensor (Bank 2, Sensor 1) Heater Circuit Malfunction

Scheme 28

Scheme 29

Scheme 30

Scheme 31

Scheme 32

Scheme 33

Scheme 34

DTC P0137: Rear Secondary HO2S (Bank 1, Sensor 2) Circuit Low Voltage; DTC P0157: Front Secondary HO2S (Bank 2, Sensor 2) Circuit Low Voltage

Scheme 35

Scheme 36

Scheme 37

DTC P0138: Rear Secondary HO2S (Bank 1, Sensor 2) Circuit High Voltage; DTC P0158: Front Secondary HO2S (Bank 2, Sensor 2) Circuit High Voltage

Scheme 38

Scheme 39

Scheme 40

DTC P0139: Rear Secondary HO2S (Bank 1, Sensor 2) Slow Response; DTC P0159: Front Secondary HO2S (Bank 2, Sensor 2) Slow Response

DTC P0141: Rear Secondary HO2S (Bank 1, Sensor 2) Heater Circuit Malfunction; DTC P0161: Front Secondary HO2S (Bank 2, Sensor 2) Heater Circuit Malfunction

Scheme 41

Scheme 42

Scheme 43

Scheme 44

Scheme 45

Scheme 46

DTC P0171: Rear Bank (Bank 1) Fuel System Too Lean; DTC P0172: Rear Bank (Bank 1) Fuel System Too Rich; DTC P0174: Front Bank (Bank 2) Fuel System Too Lean; DTC P0175: Front Bank (Bank 2) Fuel System Too Rich

DTC P0301: No. 1 Cylinder Misfire Detected; DTC P0302: No. 2 Cylinder Misfire Detected; DTC P0303: No. 3 Cylinder Misfire Detected; DTC P0304: No. 4 Cylinder Misfire Detected; DTC P0305: No. 5 Cylinder Misfire Detected; DTC P0306: No. 6 Cylinder Misfire Detected

Scheme 47

Scheme 48

Scheme 49

Scheme 50

Scheme 51

Scheme 52

DTC P0325: Knock Sensor Circuit Malfunction

Scheme 53

Scheme 54

Scheme 55

Scheme 56