Vtec Acura TL III

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DTC Troubleshooting

DTC TROUBLESHOOTING INDEX

Special Tools Required

1. Pressure gauge adapter 07NAJ-P07010A
2. A/T low pressure gauge w/panel 07406-0070300
3. A/T pressure hose 07406-0020201
4. A/T pressure hose, 2,210 mm 07MAJ-PY4011A
5. A/T pressure adapter 07MAJ-PY40120
6. 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 ).

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1. Check the engine oil level. Is the level OK? YES - Go to step 2 . NO - Adjust the engine oil to the proper level, then go to step 20 .
2. Turn the ignition switch ON (II).
3. Clear the DTC with the HDS.
4. Do the VTEC TEST in the INSPECTION MENU with the HDS. Is the result OK? YES - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the rocker arm oil pressure switch (VTEC oil pressure switch), the rocker arm oil control solenoid (VTEC solenoid valve), and the ECM/PCM. NO - Go to step 5 .
5. Turn the ignition switch OFF.
6. Disconnect the rocker arm oil pressure switch (VTEC oil pressure switch) 2P connector.
7. Turn the ignition switch ON (II).
8. Check the VTEC PRES SW in the DATA LIST with the HDS. Is ON indicated? YES - Go to step 14 . NO - Go to step 9 .
9. Turn the ignition switch OFF.
10. Remove the rocker arm oil pressure switch (VTEC oil pressure switch) (A) and install the special tools as shown, then attach the rocker arm oil pressure switch (VTEC oil pressure switch) (A) to the oil pressure gauge adapter (B). NOTE: Install the switch in the reverse order of removal with a new O-ring.
11. Start the engine.
12. Do the VTEC TEST in the INSPECTION MENU with the HDS.
13. Check the oil pressure. Does the oil pressure increase to 392 kPa (4.0 kgf/cm 2 , 56.9 psi)? YES - Replace the rocker arm oil pressure switch (VTEC oil pressure switch) (see «ROCKER ARM OIL PRESSURE SWITCH (VTEC OIL PRESSURE SWITCH) REMOVAL/INSTALLATION»(/acura/tl/iii-2003-2006/remont/testing-diagnostics/#vtec) ), then go to step 19 . NO - Inspect the VTEC system. If it is OK. Replace the rocker arm oil control solenoid (VTEC solenoid valve) (see «ROCKER ARM OIL CONTROL SOLENOID (VTEC SOLENOID VALVE) REPLACEMENT»(/acura/tl/iii-2003-2006/remont/testing-diagnostics/#vtec) ), then go to step 19 .
14. Turn the ignition switch OFF.
15. Jump the SCS line with the HDS.
16. Disconnect ECM/PCM connector E (31P).
17. Check for continuity between ECM/PCM connector terminal E23 and body ground. Is there continuity? YES - Repair short in the wire between the ECM/PCM (E23) and the rocker arm oil pressure switch (VTEC oil pressure switch), then go to step 18 . NO - Go to step 25 .
18. Reconnect all connectors.
19. Turn the ignition switch ON (II).
20. Reset the ECM/PCM with the HDS.
21. Do the ECM/PCM idle learn procedure (see «ECM/PCM IDLE LEARN PROCEDURE»(/acura/tl/iii-2003-2006/remont/testing-diagnostics/#idle-control-system__ecmpcm-idle-learn-procedure) ).
22. Do the VTEC TEST in the INSPECTION MENU with the HDS.
23. Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P2646 is indicated, check for poor connections or loose terminals at the rocker arm oil pressure switch (VTEC oil pressure switch), the rocker arm oil control solenoid (VTEC solenoid valve), and the ECM/PCM, then go to step 1 . If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting. NO - Go to step 24 .
24. Monitor the OBD STATUS for DTC P2646 in the DTCs MENU with the HDS. Does the screen indicate PASSED? YES - Troubleshooting is complete. NO - If the screen indicates FAILED, go to step 1 and recheck. If the screen indicates NOT COMPLETED, go to step 22 and recheck.
25. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM (see «HOW TO TROUBLESHOOT CIRCUITS AT THE ECM/PCM»(/acura/tl/iii-2003-2006/remont/auxiliary-emission-control-systems/#fuel-and-emissions-systems__how-to-troubleshoot-circuits-at-the) ).
26. Do the VTEC TEST in the INSPECTION MENU with the HDS.
27. Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P2646 is indicated, check for poor connections or loose terminals at the rocker arm oil pressure switch (VTEC oil pressure switch), the rocker arm oil control solenoid (VTEC solenoid valve), and the ECM/PCM then go to step 1 . If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting. NO - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(/acura/tl/iii-2003-2006/remont/testing-diagnostics/#pgm-fi-system) ).

Special Tools Required

1. Pressure gauge adapter 07NAJ-P07010A
2. A/T low pressure gauge w/panel 07406-0070300
3. A/T pressure hose 07406-0020201
4. A/T pressure hose, 2,210 mm 07MAJ-PY4011A
5. A/T pressure adapter 07MAJ-PY40120
6. 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 ).

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Scheme 456

1. Check the engine oil level. Is the level OK? YES - Go to step 2 . NO - Adjust the engine oil to the proper level, then go to step 20 .
2. Turn the ignition switch ON (II).
3. Clear the DTC with the HDS.
4. Do the VTEC TEST in the INSPECTION MENU with the HDS. Is the result OK? YES - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the rocker arm oil pressure switch (VTEC oil pressure switch), the rocker arm oil control solenoid (VTEC solenoid valve), and the ECM/PCM. NO - Go to step 5 .
5. Turn the ignition switch OFF.
6. Disconnect the rocker arm oil pressure switch (VTEC oil pressure switch) 2P connector.
7. Turn the ignition switch ON (II).
8. Check the VTEC PRES SW in the DATA LIST with the HDS. Is ON indicated? YES - Go to step 14 . NO - Go to step 9 .
9. Turn the ignition switch OFF.
10. Remove the rocker arm oil pressure switch (VTEC oil pressure switch) (A) and install the special tools as shown, then attach the rocker arm oil pressure switch (VTEC oil pressure switch) (A) to the oil pressure gauge adapter (B). NOTE: Install the switch in the reverse order of removal with a new O-ring.
11. Start the engine.
12. Do the VTEC TEST in the INSPECTION MENU with the HDS.
13. Check the oil pressure. Does the oil pressure increase to 392 kPa (4.0 kgf/cm 2 , 56.9 psi)? YES - Replace the rocker arm oil pressure switch (VTEC oil pressure switch) (see «ROCKER ARM OIL PRESSURE SWITCH (VTEC OIL PRESSURE SWITCH) REMOVAL/INSTALLATION»(/acura/tl/iii-2003-2006/remont/testing-diagnostics/#vtec) ), then go to step 19 . NO - Inspect the VTEC system. If it is OK. Replace the rocker arm oil control solenoid (VTEC solenoid valve) (see «ROCKER ARM OIL CONTROL SOLENOID (VTEC SOLENOID VALVE) REPLACEMENT»(/acura/tl/iii-2003-2006/remont/testing-diagnostics/#vtec) ), then go to step 19 .
14. Turn the ignition switch OFF.
15. Jump the SCS line with the HDS.
16. Disconnect ECM/PCM connector A (31P).
17. Check for continuity between ECM/PCM connector terminal A23 and body ground. Is there continuity? YES - Repair short in the wire between the ECM/PCM (A23) and the rocker arm oil pressure switch (VTEC oil pressure switch), then go to step 18 . NO - Go to step 25 .
18. Reconnect all connectors.
19. Turn the ignition switch ON (II).
20. Reset the ECM/PCM with the HDS.
21. Do the ECM/PCM idle learn procedure (see «ECM/PCM IDLE LEARN PROCEDURE»(/acura/tl/iii-2003-2006/remont/testing-diagnostics/#idle-control-system__ecmpcm-idle-learn-procedure) ).
22. Do the VTEC TEST in the INSPECTION MENU with the HDS.
23. Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P2646 is indicated, check for poor connections or loose terminals at the rocker arm oil pressure switch (VTEC oil pressure switch), the rocker arm oil control solenoid (VTEC solenoid valve), and the ECM/PCM, then go to step 1 . If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting. NO - Go to step 24 .
24. Monitor the OBD STATUS for DTC P2646 in the DTCs MENU with the HDS. Does the screen indicate PASSED? YES - Troubleshooting is complete. NO - If the screen indicates FAILED, go to step 1 and recheck. If the screen indicates NOT COMPLETED, go to step 22 and recheck.
25. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM (see «HOW TO TROUBLESHOOT CIRCUITS AT THE ECM/PCM»(/acura/tl/iii-2003-2006/remont/auxiliary-emission-control-systems/#fuel-and-emissions-systems__how-to-troubleshoot-circuits-at-the) ).
26. Do the VTEC TEST in the INSPECTION MENU with the HDS.
27. Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P2646 is indicated, check for poor connections or loose terminals at the rocker arm oil pressure switch (VTEC oil pressure switch), the rocker arm oil control solenoid (VTEC solenoid valve), and the ECM/PCM then go to step 1 . If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting. NO - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(/acura/tl/iii-2003-2006/remont/testing-diagnostics/#pgm-fi-system) ).

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

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1. Check the engine oil level. Is the level OK? YES - Go to step 2 . NO - Adjust the engine oil to the proper level, then go to step 14 .
2. Turn the ignition switch ON (II).
3. Clear the DTC with the HDS.
4. Do the VTEC TEST in the INSPECTION MENU with the HDS. Is the result OK? YES - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the rocker arm oil pressure switch (VTEC oil pressure switch), the rocker arm oil control solenoid (VTEC solenoid valve), and the ECM/PCM. NO - Go to step 5 .
5. Check the result of step 4 . Rocker arm oil pressure switch (VTEC Oil Pressure Switch) Failure Rocker arm oil pressure switch (VTEC Oil Pressure Switch) Open Rocker arm oil pressure switch (VTEC Oil Pressure Switch) SIG Line Open Rocker arm oil pressure switch (VTEC Oil Pressure Switch) GND Line Open Is the test result one of the above? YES - Go to step 6 . NO - Check for poor connections or loose terminals at the rocker arm oil pressure switch (VTEC oil pressure switch). If it is OK, replace the rocker arm oil control solenoid (VTEC solenoid valve) (see «ROCKER ARM OIL CONTROL SOLENOID (VTEC SOLENOID VALVE) REPLACEMENT»(/acura/tl/iii-2003-2006/remont/testing-diagnostics/#vtec) ), then go to step 14 .
6. Turn the ignition switch OFF.
7. Disconnect the rocker arm oil pressure switch (VTEC oil pressure switch) 2P connector.
8. At the rocker arm oil pressure switch (VTEC oil pressure switch), check for continuity between rocker arm oil pressure switch (VTEC oil pressure switch) 2P connector terminals No. 1 and No. 2. Is there continuity? YES - Go to step 9 . NO - Replace the rocker arm oil pressure switch (VTEC oil pressure switch) (see «ROCKER ARM OIL PRESSURE SWITCH (VTEC OIL PRESSURE SWITCH) REMOVAL/INSTALLATION»(/acura/tl/iii-2003-2006/remont/testing-diagnostics/#vtec) ), then go to step 13 .
9. Turn the ignition switch ON (II).
10. Measure voltage between rocker arm oil pressure switch (VTEC oil pressure switch) 2P connector terminal No. 1 and body ground. Is there battery voltage? YES -Repair open in the wire between the rocker arm oil pressure switch (VTEC oil pressure switch) and G101, then go to step 13 . NO - Go to step 11 .
11. Measure voltage between ECM/PCM connector terminal E23 and body ground. Is there battery voltage? YES - Repair open in the wire between the ECM/PCM (E23) and the rocker arm oil pressure switch (VTEC oil pressure switch), then go to step 12 . NO - Go to step 19 .
12. Turn the ignition switch OFF.
13. Reconnect all connectors.
14. Turn the ignition switch ON (II).
15. Reset the ECM/PCM with the HDS.
16. Do the ECM/PCM idle learn procedure (see «ECM/PCM IDLE LEARN PROCEDURE»(/acura/tl/iii-2003-2006/remont/testing-diagnostics/#idle-control-system__ecmpcm-idle-learn-procedure) ).
17. Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES -If DTC P2647 is indicated, check for poor connections or loose terminals at the rocker arm oil pressure switch (VTEC oil pressure switch) and the ECM/PCM, then go to step 1 . If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting. NO - Go to step 18 .
18. Monitor the OBD STATUS for DTC P2647 in the DTCs MENU with the HDS. Does the screen indicate PASSED? YES - Troubleshooting is complete. NO - If the screen indicates FAILED, go to step 1 and recheck. If the screen indicates NOT COMPLETED, go to step 16 and recheck.
19. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM (see «HOW TO TROUBLESHOOT CIRCUITS AT THE ECM/PCM»(/acura/tl/iii-2003-2006/remont/auxiliary-emission-control-systems/#fuel-and-emissions-systems__how-to-troubleshoot-circuits-at-the) ).
20. Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P2647 is indicated, check for poor connections or loose terminals at the rocker arm oil pressure switch (VTEC oil pressure switch) and the ECM/PCM, then go to step 1 . If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting. NO - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(/acura/tl/iii-2003-2006/remont/testing-diagnostics/#pgm-fi-system) ).

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

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1. Check the engine oil level. Is the level OK? YES - Go to step 2 . NO - Adjust the engine oil to the proper level, then go to step 14 .
2. Turn the ignition switch ON (II).
3. Clear the DTC with the HDS.
4. Do the VTEC TEST in the INSPECTION MENU with the HDS. Is the result OK? YES - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the rocker arm oil pressure switch (VTEC oil pressure switch) and the ECM/PCM. NO - Go to step 5 .
5. Check the result of step 4 . Rocker arm oil pressure switch (VTEC Oil Pressure Switch) Failure Rocker arm oil pressure switch (VTEC Oil Pressure Switch) Open Rocker arm oil pressure switch (VTEC Oil Pressure Switch) SIG Line Open Rocker arm oil pressure switch (VTEC Oil Pressure Switch) GND Line Open Is the test result one of the above? YES - Go to step 6 . NO - Check for poor connections or loose terminals at the rocker arm oil pressure switch (VTEC oil pressure switch). If it is OK, replace the rocker arm oil control solenoid (VTEC solenoid valve) (see «ROCKER ARM OIL CONTROL SOLENOID (VTEC SOLENOID VALVE) REPLACEMENT»(/acura/tl/iii-2003-2006/remont/testing-diagnostics/#vtec) ), then go to step 14 .
6. Turn the ignition switch OFF.
7. Disconnect the rocker arm oil pressure switch (VTEC oil pressure switch) 2P connector.
8. At the rocker arm oil pressure switch (VTEC oil pressure switch), check for continuity between rocker arm oil pressure switch (VTEC oil pressure switch) 2P connector terminals No. 1 and No. 2. Is there continuity? YES - Go to step 9 . NO - Replace the rocker arm oil pressure switch (VTEC oil pressure switch) (see «ROCKER ARM OIL PRESSURE SWITCH (VTEC OIL PRESSURE SWITCH) REMOVAL/INSTALLATION»(/acura/tl/iii-2003-2006/remont/testing-diagnostics/#vtec) ), then go to step 13 .
9. Turn the ignition switch ON (II).
10. Measure voltage between rocker arm oil pressure switch (VTEC oil pressure switch) 2P connector terminal No. 1 and body ground. Is there battery voltage? YES - Repair open in the wire between the rocker arm oil pressure switch (VTEC oil pressure switch) and G101, then go to step 13 . NO - Go to step 11 .
11. Measure voltage between ECM/PCM connector terminal A23 and body ground. Is there battery voltage? YES - Repair open in the wire between the ECM/PCM (A23) and the rocker arm oil pressure switch (VTEC oil pressure switch), then go to step 12 . NO - Go to step 19 .
12. Turn the ignition switch OFF.
13. Reconnect all connectors.
14. Turn the ignition switch ON (II).
15. Reset the ECM/PCM with the HDS.
16. Do the ECM/PCM idle learn procedure (see «ECM/PCM IDLE LEARN PROCEDURE»(/acura/tl/iii-2003-2006/remont/testing-diagnostics/#idle-control-system__ecmpcm-idle-learn-procedure) ).
17. Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P2647 is indicated, check for poor connections or loose terminals at the rocker arm oil pressure switch (VTEC oil pressure switch) and the ECM/PCM, then go to step 1 . If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting. NO - Go to step 18 .
18. Monitor the OBD STATUS for DTC P2647 in the DTCs MENU with the HDS. Does the screen indicate PASSED? YES - Troubleshooting is complete. NO - If the screen indicates FAILED, go to step 1 and recheck. If the screen indicates NOT COMPLETED, go to step 16 and recheck.
19. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM (see «HOW TO TROUBLESHOOT CIRCUITS AT THE ECM/PCM»(/acura/tl/iii-2003-2006/remont/auxiliary-emission-control-systems/#fuel-and-emissions-systems__how-to-troubleshoot-circuits-at-the) ).
20. Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P2647 is indicated, check for poor connections or loose terminals at the rocker arm oil pressure switch (VTEC oil pressure switch) and the ECM/PCM, then go to step 1 . If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting. NO - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(/acura/tl/iii-2003-2006/remont/testing-diagnostics/#pgm-fi-system) ).

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

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1. Turn the ignition switch ON (II).
2. Clear the DTC with the HDS.
3. Do the VTEC TEST in the INSPECTION MENU with the HDS. Is the result OK? YES - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the rocker arm oil control solenoid (VTEC solenoid valve) and the ECM/PCM. NO - Go to step 4 .
4. Turn the ignition switch OFF.
5. Disconnect the rocker arm oil control solenoid (VTEC solenoid valve) 1P connector.
6. Measure resistance between the rocker arm oil control solenoid (VTEC solenoid valve) 1P connector terminal and the solenoid valve body. Is there 14-30 ohm at room temperature? YES - Go to step 7 . NO - Go to step 10 .
7. Jump the SCS line with the HDS.
8. Disconnect ECM/PCM connector E (31P).
9. Check for continuity between ECM/PCM connector terminal E22 and body ground. Is there continuity? YES - Repair short in the wire between the ECM/PCM (E22) and the rocker arm oil control solenoid (VTEC solenoid valve), then go to step 11 . NO - Go to step 18 .
10. Replace the rocker arm oil control solenoid (VTEC solenoid valve) (see «ROCKER ARM OIL CONTROL SOLENOID (VTEC SOLENOID VALVE) REPLACEMENT»(/acura/tl/iii-2003-2006/remont/testing-diagnostics/#vtec) ).
11. Reconnect all connectors.
12. Turn the ignition switch ON (II).
13. Reset the ECM/PCM with the HDS.
14. Do the ECM/PCM idle learn procedure (see «ECM/PCM IDLE LEARN PROCEDURE»(/acura/tl/iii-2003-2006/remont/testing-diagnostics/#idle-control-system__ecmpcm-idle-learn-procedure) ).
15. Do the VTEC TEST in the INSPECTION MENU with the HDS.
16. Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P2648 is indicated, check for poor connections or loose terminals at the rocker arm oil control solenoid (VTEC solenoid valve) and the ECM/PCM, then go to step 1 . If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting. NO - Go to step 17 .
17. Monitor the OBD STATUS for DTC P2648 in the DTCs MENU with the HDS. Does the screen indicate PASSED? YES - Troubleshooting is complete. NO - If the screen indicates FAILED, go to step 1 and recheck. If the screen indicates NOT COMPLETED, go to step 15 and recheck.
18. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM (see «HOW TO TROUBLESHOOT CIRCUITS AT THE ECM/PCM»(/acura/tl/iii-2003-2006/remont/auxiliary-emission-control-systems/#fuel-and-emissions-systems__how-to-troubleshoot-circuits-at-the) ).
19. Do the VTEC TEST in the INSPECTION MENU with the HDS.
20. Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES -If DTC P2648 is indicated, check for poor connections or loose terminals at the rocker arm oil control solenoid (VTEC solenoid valve) and the ECM/PCM, then go to step 1 . If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting. NO -If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(/acura/tl/iii-2003-2006/remont/testing-diagnostics/#pgm-fi-system) ).

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

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Scheme 466

1. Turn the ignition switch ON (II).
2. Clear the DTC with the HDS.
3. Do the VTEC TEST in the INSPECTION MENU with the HDS. Is the result OK? YES - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the rocker arm oil control solenoid (VTEC solenoid valve) and the ECM/PCM. NO - Go to step 4 .
4. Turn the ignition switch OFF.
5. Disconnect the rocker arm oil control solenoid (VTEC solenoid valve) 1P connector.
6. Measure resistance between the rocker arm oil control solenoid (VTEC solenoid valve) 1P connector terminal and the solenoid valve body. Is there 14-30ohm at room temperature? YES - Go to step 7 . NO - Go to step 10 .
7. Jump the SCS line with the HDS.
8. Disconnect ECM/PCM connector A (31P).
9. Check for continuity between ECM/PCM connector terminal A22 and body ground. Is there continuity? YES - Repair short in the wire between the ECM/PCM (A22) and the rocker arm oil control solenoid (VTEC solenoid valve), then go to step 11 . NO - Go to step 18 .
10. Replace the rocker arm oil control solenoid (VTEC solenoid value) (see «ROCKER ARM OIL CONTROL SOLENOID (VTEC SOLENOID VALVE) REPLACEMENT»(/acura/tl/iii-2003-2006/remont/testing-diagnostics/#vtec) ).
11. Reconnect all connectors.
12. Turn the ignition switch ON (II).
13. Reset the ECM/PCM with the HDS.
14. Do the ECM/PCM idle learn procedure (see «ECM/PCM IDLE LEARN PROCEDURE»(/acura/tl/iii-2003-2006/remont/testing-diagnostics/#idle-control-system__ecmpcm-idle-learn-procedure) ).
15. Do the VTEC TEST in the INSPECTION MENU with the HDS.
16. Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P2648 is indicated, check for poor connections or loose terminals at the rocker arm oil control solenoid (VTEC solenoid valve) and the ECM/PCM, then go to step 1 . If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting. NO - Go to step 17 .
17. Monitor the OBD STATUS for DTC P2648 in the DTCs MENU with the HDS. Does the screen indicate PASSED? YES - Troubleshooting is complete. NO - If the screen indicates FAILED, go to step 1 and recheck. If the screen indicates NOT COMPLETED, go to step 15 and recheck.
18. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM (see «HOW TO TROUBLESHOOT CIRCUITS AT THE ECM/PCM»(/acura/tl/iii-2003-2006/remont/auxiliary-emission-control-systems/#fuel-and-emissions-systems__how-to-troubleshoot-circuits-at-the) ).
19. Do the VTEC TEST in the INSPECTION MENU with the HDS.
20. Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P2648 is indicated, check for poor connections or loose terminals at the rocker arm oil control solenoid (VTEC solenoid valve) and the ECM/PCM, then go to step 1 . If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting. NO - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(/acura/tl/iii-2003-2006/remont/testing-diagnostics/#pgm-fi-system) ).

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

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Scheme 469

1. Turn the ignition switch ON (II).
2. Clear the DTC with the HDS.
3. Start the engine. Hold the engine speed at 3,000 RPM without load (in Park or neutral) until the radiator fan comes on, then let it idle.
4. Check for Temporary DTCs or DTCs with the HDS. Is DTC P2649 indicated? YES - Go to step 5 . NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the rocker arm oil control solenoid (VTEC solenoid valve) and the ECM/PCM.
5. Turn the ignition switch OFF.
6. Disconnect the rocker arm oil control solenoid (VTEC solenoid valve) 1P connector.
7. Measure resistance between the rocker arm oil control solenoid (VTEC solenoid valve) 1P connector terminal and the solenoid valve body. Is there 14-30 ohm ? YES - Go to step 8 . NO - Go to step 12 .
8. Jump the SCS line with the HDS.
9. Disconnect ECM/PCM connector E (31P).
10. Connect the rocker arm oil control solenoid (VTEC solenoid valve) 1P connector terminal to body ground with a jumper wire.
11. Check for continuity between ECM/PCM connector terminal E22 and body ground. Is there continuity? YES - Go to step 20 . NO - Repair open in the wire between the ECM/PCM (E22) and the rocker arm oil control solenoid (VTEC solenoid valve), then go to step 13 .
12. Replace the rocker arm oil control solenoid (VTEC solenoid valve) (see «ROCKER ARM OIL CONTROL SOLENOID (VTEC SOLENOID VALVE) REPLACEMENT»(/acura/tl/iii-2003-2006/remont/testing-diagnostics/#vtec) ).
13. Reconnect all connectors.
14. Turn the ignition switch ON (II).
15. Reset the ECM/PCM with the HDS.
16. Do the ECM/PCM idle learn procedure (see «ECM/PCM IDLE LEARN PROCEDURE»(/acura/tl/iii-2003-2006/remont/testing-diagnostics/#idle-control-system__ecmpcm-idle-learn-procedure) ).
17. Start the engine. Hold the engine speed at 3,000 RPM without load (in Park or neutral) until the radiator fan comes on, then let it idle.
18. Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P2649 is indicated, check for poor connections or loose terminals at the rocker arm oil control solenoid (VTEC solenoid valve) and the ECM/PCM, then go to step 1 . If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting. NO - Go to step 19 .
19. Monitor the OBD STATUS for DTC P2649 in the DTCs MENU with the HDS. Does the screen indicate PASSED? YES - Troubleshooting is complete. NO - If the screen indicates FAILED, go to step 1 and recheck. If the screen indicates NOT COMPLETED, go to step 17 and recheck.
20. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM (see «HOW TO TROUBLESHOOT CIRCUITS AT THE ECM/PCM»(/acura/tl/iii-2003-2006/remont/auxiliary-emission-control-systems/#fuel-and-emissions-systems__how-to-troubleshoot-circuits-at-the) ).
21. Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P2649 is indicated, check for poor connections or loose terminals at the rocker arm oil control solenoid (VTEC solenoid valve) and the ECM/PCM, then go to step 1 . If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting. NO - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(/acura/tl/iii-2003-2006/remont/testing-diagnostics/#pgm-fi-system) ).

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

Scheme 470

Scheme 471

Scheme 472

1. Turn the ignition switch ON (II).
2. Clear the DTC with the HDS.
3. Start the engine. Hold the engine speed at 3,000 RPM without load (in Park or neutral) until the radiator fan comes on, then let it idle.
4. Check for Temporary DTCs or DTCs with the HDS. Is DTC P2649 indicated? YES - Go to step 5 . NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the rocker arm oil control solenoid (VTEC solenoid valve) and the ECM/PCM.
5. Turn the ignition switch OFF.
6. Disconnect the rocker arm oil control solenoid (VTEC solenoid valve) 1P connector.
7. Measure resistance between the rocker arm oil control solenoid (VTEC solenoid valve) 1P connector terminal and the solenoid valve body. Is there 14-30 ohm ? YES - Go to step 8 . NO - Go to step 12 .
8. Jump the SCS line with the HDS.
9. Disconnect ECM/PCM connector A (31P).
10. Connect the rocker arm oil control solenoid (VTEC solenoid valve) 1P connector terminal to body ground with a jumper wire.
11. Check for continuity between ECM/PCM connector terminal A22 and body ground. Is there continuity? YES - Go to step 20 . NO - Repair open in the wire between the ECM/PCM (A22) and the rocker arm oil control solenoid (VTEC solenoid valve), then go to step 13 .
12. Replace the rocker arm oil control solenoid (VTEC solenoid valve) (see «ROCKER ARM OIL CONTROL SOLENOID (VTEC SOLENOID VALVE) REPLACEMENT»(/acura/tl/iii-2003-2006/remont/testing-diagnostics/#vtec) ).
13. Reconnect all connectors.
14. Turn the ignition switch ON (II).
15. Reset the ECM/PCM with the HDS.
16. Do the ECM/PCM idle learn procedure (see «ECM/PCM IDLE LEARN PROCEDURE»(/acura/tl/iii-2003-2006/remont/testing-diagnostics/#idle-control-system__ecmpcm-idle-learn-procedure) ).
17. Start the engine. Hold the engine speed at 3,000 RPM without load (in Park or neutral) until the radiator fan comes on, then let it idle.
18. Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P2649 is indicated, check for poor connections or loose terminals at the rocker arm oil control solenoid (VTEC solenoid valve) and the ECM/PCM, then go to step 1 . If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting. NO - Go to step 19 .
19. Monitor the OBD STATUS for DTC P2649 in the DTCs MENU with the HDS. Does the screen indicate PASSED? YES - Troubleshooting is complete. NO - If the screen indicates FAILED, go to step 1 and recheck. If the screen indicates NOT COMPLETED, go to step 17 and recheck.
20. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM (see «HOW TO TROUBLESHOOT CIRCUITS AT THE ECM/PCM»(/acura/tl/iii-2003-2006/remont/auxiliary-emission-control-systems/#fuel-and-emissions-systems__how-to-troubleshoot-circuits-at-the) ).
21. Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P2649 is indicated, check for poor connections or loose terminals at the rocker arm oil control solenoid (VTEC solenoid valve) and the ECM/PCM, then go to step 1 . If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting. NO - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(/acura/tl/iii-2003-2006/remont/testing-diagnostics/#pgm-fi-system) ).

Scheme 473

Scheme 474

Scheme 475

1. Disconnect the rocker arm oil control solenoid (VTEC solenoid valve) connector.
2. Measure resistance between the rocker arm oil control solenoid (VTEC solenoid valve) 1P connector terminal (A) and body ground. If the resistance is as specified, go to step 3 . If the resistance is not as specified, replace the rocker arm oil control solenoid (VTEC solenoid valve).
3. Remove the rocker arm oil control solenoid (VTEC solenoid valve)/oil filter assembly (A) from the oil pump, and check the rocker arm oil control solenoid (VTEC solenoid valve) filter (B) for a restriction. If there is a restriction, replace the rocker arm oil control solenoid (VTEC solenoid valve) filter, the engine oil filter, and the engine oil.
4. If the filter is not restricted, remove the rocker arm oil control solenoid (VTEC solenoid valve) (A), and push the valve (B) with your finger to check its movement. If the valve moves freely, it is normal; check the engine oil pressure. If the valve binds or sticks, replace the rocker arm oil control solenoid (VTEC solenoid valve)/oil filter assembly.

Scheme 476

1. Disconnect the rocker arm oil control solenoid (VTEC solenoid valve) connector (A).
2. Remove the rocker arm oil control solenoid (VTEC solenoid valve) (B).
3. Install the parts in the reverse order of removal with a new O-ring (C).

Scheme 477

1. Disconnect the rocker arm oil pressure switch (VTEC oil pressure switch) connector (A), then remove the rocker arm oil pressure switch (VTEC oil pressure switch) (B).
2. Install the switch in the reverse order of removal with a new O-ring (C).

See also:
• GENERAL TROUBLESHOOTING INFORMATION
• ECM/PCM IDLE LEARN PROCEDURE
• HOW TO TROUBLESHOOT CIRCUITS AT THE ECM/PCM
• ECM/PCM REPLACEMENT
• DTC P2646