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Home/Acura/MDX/Acura MDX II facelift (2010-2013)/Repair manual/Testing & Diagnostics/Idle Control System: Overview
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Idle Control System: Overview Acura MDX II facelift

Testing & Diagnostics 10 illustrations ~2246 words

Scheme 268

Scheme 268: Component Location Index
Scheme 268: Component Location Index

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

  1. Turn the ignition switch to ON (II).
  2. Clear the DTC with the HDS.
  3. 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 20 seconds.
  4. Check for these conditions in the DATA LIST with the HDS: ECT SENSOR 1 above 158°F (70°C) IAT SENSOR above 19°F (-7°C) VEHICLE SPEED is 0 mph (0 km/h) ST FUEL TRIM between 0.8-1.21 FSS is CLOSED
  5. Monitor the OBD STATUS for DTC P0506 in the DTCs MENU with the HDS. Does the HDS indicate FAILED? YES -Go to step 6. NO -If the HDS indicates PASSED, go to step 15 . If the HDS indicates EXECUTING, keep idling until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 4 and recheck.
  6. Remove the intake air duct from the throttle body (see «THROTTLE BODY REMOVAL/INSTALLATION»(ref-510444-S04768306062012102300000) ).
  7. Check for dirt, carbon, or damage in the throttle bore. Is there dirt, carbon, or damage in the throttle bore? YES -If there is dirt or carbon, clean the throttle body (see «THROTTLE BODY TEST»(ref-510444-S09246197812012102300000) ). Also check for damage to the air cleaner element (see «AIR CLEANER REMOVAL/INSTALLATION»(ref-510444-S34860790982012102300000) ), then go to step 9 . If there is damage in the throttle bore, go to step 8. NO -Check the A/C system or the power steering system, then go to step 9 .
  8. Replace the throttle body (see «THROTTLE BODY REMOVAL/INSTALLATION»(ref-510444-S04768306062012102300000) ).
  9. Reset the PCM with the HDS.
  10. Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(ref-510456-S37172493852012102300000) ).
  11. 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 20 seconds.
  12. Check for these conditions in the DATA LIST with the HDS: ECT SENSOR 1 above 158°F (70°C) IAT SENSOR above 19°F (-7°C) VEHICLE SPEED is 0 mph (0 km/h) ST FUEL TRIM between 0.8-1.21 FSS is CLOSED
  13. Check for Pending or Confirmed DTCs with the HDS. Is DTC P0506 indicated? YES -Go to step 1 and recheck. NO -Go to step 14.
  14. Monitor the OBD STATUS for DTC P0506 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 «DTCS TROUBLESHOOTING»(ref-510456-S31556451382012102300000) . NO -If the HDS indicates FAILED, check the A/C system and/or the power steering system, 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 12 .
  15. Remove the intake air duct from the throttle body (see «THROTTLE BODY REMOVAL/INSTALLATION»(ref-510444-S04768306062012102300000) ).
  16. Check for dirt, carbon, or damage in the throttle bore. Is there dirt, carbon, or damage in the throttle bore? YES -If there is dirt or carbon, clean the throttle body (see «THROTTLE BODY TEST»(ref-510444-S09246197812012102300000) ). Also check for damage to the air cleaner element (see «AIR CLEANER REMOVAL/INSTALLATION»(ref-510444-S34860790982012102300000) ), then go to step 9 . If there is damage in the throttle bore, go to step 8 . NO -Go to step 17.
  17. Recheck with different load conditions (turn on the headlights, the blower motor, the rear window defogger and/or the A/C, change the gear position, etc.).
  18. Monitor the OBD STATUS for DTC P0506 in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -Intermittent failure, the system is OK at this time. NO -If the HDS indicates FAILED, check the A/C system and/or the power steering system, then go to step 1 and recheck. If the HDS indicates EXECUTING, keep idling until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 12 .

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

  1. Turn the ignition switch to ON (II).
  2. Clear the DTC with the HDS.
  3. 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 20 seconds.
  4. Monitor the OBD STATUS for DTC P0507 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. If the HDS indicates EXECUTING, keep idling until a result comes on. If the HDS indicates OUT OF CONDITION, recheck with different load conditions (turn on the headlights, the blower motor, or the A/C, change the gear position, etc.), then go to step 3 .
  5. Check for vacuum leaks at these parts: PCV valve PCV hose EVAP canister purge valve Throttle body Intake manifold Brake booster hose Brake booster Are there any leaks? YES -Repair or replace the leaking part(s), then go to step 6. NO -Go to step 6.
  6. Turn the ignition switch to ON (II).
  7. Reset the PCM with the HDS.
  8. Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(ref-510456-S37172493852012102300000) ).
  9. 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 20 seconds.
  10. Check for Pending or Confirmed DTCs with the HDS. Is DTC P0507 indicated? YES -Check for poor connections or loose terminals at the throttle body and the PCM, then go to step 1 . NO -Go to step 11.
  11. Monitor the OBD STATUS for DTC P0507 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 10 , go to the indicated «DTCS TROUBLESHOOTING»(ref-510456-S31556451382012102300000) . NO -If the HDS indicates FAILED, check for poor connections or loose terminals at the throttle body 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, recheck with different load conditions (turn on the headlights, the blower motor, or the A/C, change the gear position, etc.), then go to step 9 .

Scheme 269

Scheme 269: A/C Signal Circuit Troubleshooting
Scheme 269: A/C Signal Circuit Troubleshooting
  1. Start the engine.
  2. Turn the blower switch on.
  3. Turn the A/C switch on.
  4. Check the A/C CLUTCH in the DATA LIST with the HDS. Does it indicate ON? YES -Go to step 5. NO -Check the A/C system (see «GENERAL TROUBLESHOOTING INFORMATION»(ref-510445-S28568143282012102300000) ).
  5. Check the A/C system operation. Does the A/C system operate? YES -The air conditioning system circuit is OK. NO -Go to step 6.
  6. Turn the ignition switch to LOCK (0).
  7. Turn the ignition switch to ON (II).
  8. Activate the A/C CLUTCH in the INSPECTION MENU with the HDS. Is there a clicking noise from the A/C compressor clutch? YES -Do the A/C system test (see «A/C SYSTEM TEST»(ref-510445-S01839066082012102300000) ). NO -Go to step 9.
  9. Turn the ignition switch to LOCK (0).
  10. Jump the SCS line with the HDS.
  11. Disconnect PCM connector A (49P).
  12. Turn the ignition switch to ON (II).
  13. Momentarily connect PCM connector terminal A13 to body ground with a jumper wire several times. Is there a clicking noise from the A/C compressor clutch? YES -Update the PCM if it does not have the latest software (see «KNOCK SENSOR REPLACEMENT»(ref-510432-S21235871652012102300000) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(ref-510452-S32404884522012102300000) ), 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»(ref-510432-S18664843072012102300000) ). NO -Check for poor connections or loose terminals at the A/C compressor clutch relay and the PCM. If the connections are OK, check the A/C compressor clutch relay (see «POWER RELAY TEST»(ref-510453-S09972764482012102300000) ). If needed, repair an open in the wire between the PCM (A13) and the A/C compressor clutch relay and the other A/C system parts.

Scheme 270

Scheme 270: Alternator FR Signal Circuit Troubleshooting
Scheme 270: Alternator FR Signal Circuit Troubleshooting
  1. Start the engine, and let it idle.
  2. Monitor the ALTERNATOR in the DATA LIST with the HDS.
  3. Check if the indicated percentage varies when the headlight switch is turned on. Does the percentage vary? YES -The alternator signal circuit is OK. NO -Go to step 4.
  4. Turn the headlight switch OFF and ignition switch to LOCK (0).
  5. Jump the SCS line with the HDS.
  6. Disconnect the alternator 4P connector.
  7. Disconnect PCM connector C (49P).
  8. Check for continuity between body ground and PCM connector terminal C44. Is there continuity? YES -Repair a short in the wire between the PCM (C44) and the alternator. NO -Update the PCM if it does not have the latest software (see «KNOCK SENSOR REPLACEMENT»(ref-510432-S21235871652012102300000) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(ref-510452-S32404884522012102300000) ), 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»(ref-510432-S18664843072012102300000) ).

Scheme 271

Scheme 271: PSP Switch Signal Circuit Troubleshooting
Scheme 271: PSP Switch Signal Circuit Troubleshooting

Scheme 272

Scheme 272
Scheme 272

Scheme 273

Scheme 273
Scheme 273

Scheme 274

Scheme 274
Scheme 274
  1. Start the engine, and let it idle.
  2. Align the steering wheel straight ahead.
  3. Check the PSP SWITCH in the DATA LIST with the HDS. Does it indicate ON? YES -Go to step 4. NO -Go to step 14 .
  4. Turn the steering wheel to the full lock position.
  5. Check the PSP SWITCH in the DATA LIST with the HDS. Does it change to OFF? YES -The PSP switch signal circuit is OK. NO -Go to step 6.
  6. Turn the ignition switch to LOCK (0).
  7. Disconnect the PSP switch 2P connector.
  8. Start the engine.
  9. Check the PSP SWITCH in the DATA LIST with the HDS. Does it change to OFF? YES -Replace the PSP switch (see «POWER STEERING HOSE, LINE, AND PRESSURE SWITCH REPLACEMENT»(ref-510441-S02280842712012102300000) ). NO -Go to step 10.
  10. Turn the ignition switch to LOCK (0).
  11. Jump the SCS line with the HDS.
  12. Disconnect PCM connector A (49P).
  13. Check for continuity between PSP switch 2P connector terminal No. 1 and body ground. Is there continuity? YES -Repair a short in the wire between the PCM (A38) and the PSP switch. NO -Update the PCM if it does not have the latest software (see «KNOCK SENSOR REPLACEMENT»(ref-510432-S21235871652012102300000) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(ref-510452-S32404884522012102300000) ), 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»(ref-510432-S18664843072012102300000) ).
  14. Turn the ignition switch to LOCK (0).
  15. Disconnect the PSP switch 2P connector.
  16. Connect PSP switch 2P connector terminals No. 1 and No. 2 with a jumper wire, then start the engine.
  17. Check the PSP SWITCH in the DATA LIST with the HDS. Does it change to ON? YES -Replace the PSP switch (see «POWER STEERING HOSE, LINE, AND PRESSURE SWITCH REPLACEMENT»(ref-510441-S02280842712012102300000) ). NO -Go to step 18.
  18. Turn the ignition switch to LOCK (0).
  19. Remove the jumper wire from the PSP switch 2P connector.
  20. Jump the SCS line with the HDS.
  21. Disconnect PCM connector A (49P).
  22. Check for continuity between PCM connector terminal A38 and PSP switch 2P connector terminal No. 1. Is there continuity? YES -Go to step 23. NO -Repair an open in the wire between the PSP switch and the PCM (A38).
  23. Check for continuity between PSP switch 2P connector terminal No. 2 and body ground. Is there continuity? YES -Update the PCM if it does not have the latest software (see «KNOCK SENSOR REPLACEMENT»(ref-510432-S21235871652012102300000) ), or substitute a known-good PCM (see «SUBSTITUTING THE PCM»(ref-510452-S32404884522012102300000) ), 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»(ref-510432-S18664843072012102300000) ). NO -Repair an open in the wire between the PSP switch and G202.

Scheme 275

Scheme 275: Brake Pedal Position Switch Signal Circuit Troubleshooting
Scheme 275: Brake Pedal Position Switch Signal Circuit Troubleshooting

Scheme 276

Scheme 276
Scheme 276

Scheme 277

Scheme 277
Scheme 277
  1. Turn the ignition switch to ON (II).
  2. Check the BRAKE SWITCH in the DATA LIST with the HDS. Does it indicate OFF? YES -Go to step 3. NO -Inspect the brake pedal position switch (see «BRAKE PEDAL AND BRAKE PEDAL POSITION SWITCH ADJUSTMENT»(ref-510434-S42856325872012102300000) ).
  3. Press the brake pedal, and check the BRAKE SWITCH in the DATA LIST with the HDS. Does it change to ON? YES -The brake pedal position switch signal circuit (BKSW line) is OK. NO -Go to step 4.
  4. Turn the ignition switch to LOCK (0).
  5. Jump the SCS line with the HDS.
  6. Disconnect the brake pedal position switch 4P connector.
  7. Disconnect PCM connector A (49P).
  8. Check for continuity between PCM connector terminal A8 and body ground. Is there continuity? YES -Repair a short in the wire between the PCM (A8) and the brake pedal position switch. Also replace the No. 11 +B STOP & HORN(15A)fuse. NO -Go to step 9.
  9. Connect brake pedal position switch 4P connector terminal No. 2 to body ground with a jumper wire.
  10. Check for continuity between PCM connector terminal A8 and body ground. Is there continuity? YES -Repair an open or short in the wire between the brake pedal position switch and the No. 11 +B STOP & HORN (15 A) fuse in the main under-hood fuse box. If the circuit is OK, inspect the brake pedal position switch (see «BRAKE PEDAL AND BRAKE PEDAL POSITION SWITCH ADJUSTMENT»(ref-510434-S42856325872012102300000) ). NO -Repair an open in the wire between the PCM (A8) and the brake pedal position switch.

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