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Idle Control System: Overview Acura TL III facelift

Engine Control Systems 10 illustrations ~2092 words

Scheme 1

Scheme 1: Component Location Index
Scheme 1: 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 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 for 20 seconds or more.
  4. Check this data in the DATA LIST with the HDS: Engine coolant temperature (ECT SENSOR 1) above 158°F (70°C) IAT SENSOR above 32°F (0°C) VSS is 0 mph (0 km/ h) ST FUEL TRIM between 0.73 and 1.47 FSS is CLOSED
  5. Monitor the OBD STATUS for DTC P0506 in the DTCs MENU with the HDS. Does the screen indicate FAILED? YES -Go to step 6. NO -If the screen indicates PASSED, go to step 15 . If the screen indicates EXECUTING, keep idling until a result comes on. If the screen indicates OUT OF CONDITION, go to step 4 and recheck.
  6. Remove the intake air duct from the throttle body.
  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 CLEANING»(ref-291515-S02262611142008072900000) ). Also check for damage at the air cleaner element (see «AIR CLEANER ELEMENT INSPECTION/REPLACEMENT»(ref-291515-S00946676432008072900000) ), then go to step 9 . If there is damage in the throttle bore, go to step 8. NO -Check the A/C system or power steering system, then go to step 17 .
  8. Replace the throttle body (see «THROTTLE BODY REMOVAL/INSTALLATION»(ref-291515-S25118284682008072900000) ).
  9. Reset the ECM/PCM with the HDS.
  10. Do the ECM/PCM idle learn procedure (see «ECM/PCM IDLE LEARN PROCEDURE»(ref-291528-S20095377152008072900000) ).
  11. 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 for 20 seconds or more.
  12. Check this data in the DATA LIST with the HDS: Engine coolant temperature (ECT SENSOR 1) above 158°F (70°C) IAT SENSOR above 32°F (0°C) VSS is 0 mph (0 km/ h) ST FUEL TRIM between 0.73 and 1.47 FSS is CLOSED
  13. Check for Temporary DTCs or 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 screen indicate PASSED? YES -Troubleshooting is complete. If any other Temporary DTCs or DTCs were indicated in step 13 , go to the indicated «DTC'S TROUBLESHOOTING»(ref-291528-S37433600862008072900000) . NO -If the screen indicates FAILED, check the A/C system and/ or power steering system, then go to step 1 . If the screen indicates EXECUTING, keep idling until a result comes on. If the screen indicates OUT OF CONDITION, go to step 12 .
  15. Remove the intake air duct from the throttle body.
  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 CLEANING»(ref-291515-S02262611142008072900000) ). Also check for damage at the air cleaner element (see «AIR CLEANER ELEMENT INSPECTION/REPLACEMENT»(ref-291515-S00946676432008072900000) ), 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, blower motor, rear window defogger and/ or A/C, changing the gear position, etc.).
  18. Monitor the OBD STATUS for DTC P0506 in the DTCs MENU with the HDS. Does the screen indicate PASSED? YES -Intermittent failure, the system is OK at this time. NO -If the screen indicates FAILED, check the A/C system and/ or power steering system, then go to step 1 . If the screen indicates EXECUTING, keep idling until a result comes on. If the screen 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 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 for 20 seconds or more.
  4. Monitor the OBD STATUS for DTC P0507 in the DTCs MENU with the HDS. Does the screen indicate FAILED? YES -Go to step 5. NO -If the screen indicates PASSED, intermittent failure, the system is OK at this time. If the screen indicates EXECUTING, keep idling until a result comes on. If the screen indicates OUT OF CONDITION, recheck with different load conditions (electrical, A/C, 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 ON (II).
  7. Reset the ECM/PCM with the HDS.
  8. Do the ECM/PCM idle learn procedure (see «ECM/PCM IDLE LEARN PROCEDURE»(ref-291528-S20095377152008072900000) ).
  9. 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 for 20 seconds or more.
  10. Check for Temporary DTCs or DTCs with the HDS. Is DTC P0507 indicated? YES -Check for poor connections or loose terminals at the throttle body and the ECM/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 screen indicate PASSED? YES -Troubleshooting is complete. If any other Temporary DTCs or DTCs were indicated in step 10 , go to the indicated «DTC'S TROUBLESHOOTING»(ref-291528-S37433600862008072900000) . NO -If the screen indicates FAILED, check for poor connections or loose terminals at the throttle body and the ECM/PCM, then go to step 1 . If the screen indicates EXECUTING, keep idling until a result comes on. If the screen indicates OUT OF CONDITION, recheck with different load conditions (turn on the headlights, blower motor, or A/C; change the gear position, etc.), then go to step 9 .

Scheme 2

Scheme 2: A/C Signal Circuit Troubleshooting
Scheme 2: 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 -Do the A/C pressure switch circuit troubleshooting (see «RADIATOR AND A/C CONDENSER FAN HIGH SPEED CIRCUIT TROUBLESHOOTING»(ref-291516-S37442866842008072900000) ).
  5. Check the A/C system. Does the A/C system operate? YES -The air conditioning system circuit is OK. NO -Go to step 6.
  6. Turn the ignition switch OFF.
  7. Turn the ignition switch 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-291516-S41360963432008072900000) ). NO -Go to step 9.
  9. Momentarily connect under-hood fuse/ relay box 16P connector terminal No. 15 to body ground with a jumper wire several times. Is there a clicking noise from the A/C compressor clutch? YES -Repair open in the wire between the ECM/PCM (E27) and the A/C clutch relay. NO -Update the ECM/PCM if it does not have the latest software (see «UPDATING THE ECM/PCM»(ref-291525-S06490175862008072900000) ), or substitute a known-good ECM/PCM (see «SUBSTITUTING THE ECM/PCM»(ref-291525-S00620566452008072900000) ), then recheck. If the symptom/ indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(ref-291526-S06435096812008072900000) ).

Scheme 3

Scheme 3: Alternator FR Signal Circuit Troubleshooting
Scheme 3: 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 changes 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 and ignition switch OFF.
  5. Jump the SCS line with the HDS.
  6. Disconnect the alternator 4P connector.
  7. Disconnect ECM/PCM connector A (31P).
  8. Check for continuity between body ground and ECM/PCM connector terminal A12. Is there continuity? YES -Repair short in the wire between the ECM/PCM (A12) and the alternator. NO -Update the ECM/PCM if it does not have the latest software (see «UPDATING THE ECM/PCM»(ref-291525-S06490175862008072900000) ), or substitute a known-good ECM/PCM (see «SUBSTITUTING THE ECM/PCM»(ref-291525-S00620566452008072900000) ), then recheck. If the symptom/ indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(ref-291526-S06435096812008072900000) ).

Scheme 4

Scheme 4: PSP Switch Signal Circuit Troubleshooting
Scheme 4: PSP Switch Signal Circuit Troubleshooting

Scheme 5

Scheme 5
Scheme 5

Scheme 6

Scheme 6
Scheme 6

Scheme 7

Scheme 7
Scheme 7

Scheme 8

Scheme 8
Scheme 8
  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 OFF.
  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-291507-S12407542752008072900000) ). NO -Go to step 10.
  10. Turn the ignition switch OFF.
  11. Jump the SCS line with the HDS.
  12. Disconnect ECM/PCM connector E (31P).
  13. Check for continuity between PSP switch 2P connector terminal No. 1 and body ground. Is there continuity? YES -Repair short in the wire between the ECM/PCM (E17) and the PSP switch. NO -Update the ECM/PCM if it does not have the latest software (see «UPDATING THE ECM/PCM»(ref-291525-S06490175862008072900000) ), or substitute a known-good ECM/PCM (see «SUBSTITUTING THE ECM/PCM»(ref-291525-S00620566452008072900000) ), then recheck. If the symptom/ indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(ref-291526-S06435096812008072900000) ).
  14. Turn the ignition switch OFF.
  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-291507-S12407542752008072900000) ). NO -Go to step 18.
  18. Turn the ignition switch OFF.
  19. Remove the jumper wire from the PSP switch 2P connector.
  20. Jump the SCS line with the HDS.
  21. Disconnect ECM/PCM connector E (31P).
  22. Connect PSP switch 2P connector terminal No. 1 to body ground with a jumper wire.
  23. Check for continuity between body ground and ECM/PCM connector terminal E17. Is there continuity? YES -Go to step 24. NO -Repair open in the wire between the PSP switch and the ECM/PCM (E17).
  24. Check for continuity between PSP switch 2P connector terminal No. 2 and body ground. Is there continuity? YES -Update the ECM/PCM if it does not have the latest software (see «UPDATING THE ECM/PCM»(ref-291525-S06490175862008072900000) ), or substitute a known-good ECM/PCM (see «SUBSTITUTING THE ECM/PCM»(ref-291525-S00620566452008072900000) ), then recheck. If the symptom/ indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(ref-291526-S06435096812008072900000) ). NO -Repair open in the wire between the PSP switch and G302.

Scheme 9

Scheme 9: Brake Pedal Position Switch Signal Circuit Troubleshooting
Scheme 9: Brake Pedal Position Switch Signal Circuit Troubleshooting

Scheme 10

Scheme 10
Scheme 10
  1. Turn the ignition switch 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-291506-S09581179342008072900000) ).
  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 OFF.
  5. Jump the SCS line with the HDS.
  6. Disconnect the brake pedal position switch 4P connector.
  7. Disconnect ECM/PCM connector E (31P).
  8. Check for continuity between ECM/PCM connector terminal E8 and body ground. Is there continuity? YES -Repair short in the wire between the ECM/PCM (E8) and the No. 13 HORN, STOP (20 A) fuse. Replace the No. 13 HORN, STOP (20 A) fuse. NO -Go to step 9.
  9. Check for continuity between ECM/PCM connector terminal E8 and brake pedal position switch 4P connector terminal No. 2. Is there continuity? YES -Repair open in the wire between the brake pedal position switch and the No. 13 HORN, STOP (20 A) fuse. Inspect the brake pedal position switch (see «BRAKE PEDAL AND BRAKE PEDAL POSITION SWITCH ADJUSTMENT»(ref-291506-S09581179342008072900000) ). NO -Repair open in the wire between the ECM/PCM (E8) and the brake pedal position switch.

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