Acura RL. Manual - part 456

Is DTC P2138 indicated?

YES - Check for poor connections or loose terminals at the APP sensor and the PCM. If the PCM was
updated, substitute a known-good PCM (see 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 ). If any other Temporary DTCs or DTCs are indicated,
go to the indicated DTCs troubleshooting.

DTC P2176: THROTTLE ACTUATOR CONTROL SYSTEM IDLE POSITION NOT LEARNED

1. Turn the ignition switch ON (II).

2. Clear the DTC with the HDS.

3. Turn the ignition switch OFF.

4. Turn the ignition switch ON (II), and wait 10 seconds.

5. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P2176 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 throttle body and the throttle actuator control module, then clean the throttle body (see
THROTTLE BODY CLEANING ).

6. Turn the ignition switch OFF.

7. Disconnect the intake air duct from the throttle body.

8. Turn the ignition switch ON (II).

9. Clear the DTC with the HDS.

10. Do the ETCS TEST in the INSPECTION MENU with the HDS.

11. Visually check the throttle valve operation.

Does the throttle valve move to its fully closed position?

YES - Go to step 12.

NO - Go to step 13.

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 P2135 or P2552 is stored at the same time as DTC P2176,
troubleshoot DTC P2135 or P2552 first, then recheck for DTC P2176.

NOTE:

Be careful not to pinch your fingers. Keep your hands away from the
throttle valve.

2007 Acura RL

2005-08 ENGINE PERFORMANCE Electronic Throttle Control System - RL

Friday, June 05, 2009 2:29:49 PM

Page 45

12. Check for sludge or carbon on the throttle valve.

Is there sludge or carbon on the throttle valve?

YES - Clean the throttle body (see THROTTLE BODY CLEANING ), then go to step 23 and
recheck.

NO - Go to step 20.

13. Turn the ignition switch OFF.

14. Disconnect the throttle body 6P connector.

15. Disconnect the C251 connector (13P) between the PCM subharness and the throttle actuator control

module subharness.

16. Connect throttle body 6P connector terminals No. 5 and No. 6 with a jumper wire.

Fig. 57: Connecting Throttle Body 6P Connector Terminals No. 5 And No. 6 With Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.

17. Check for continuity between C251 connector (13P) terminals No. 6 and No. 13.

Fig. 58: Checking Continuity Between C251 Connector (13P) Terminals No. 6 And No. 13
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Go to step 18.

NO - Repair open in the wires between the throttle body and the C251 connector (motor drive lines),
then go to step 22.

2007 Acura RL

2005-08 ENGINE PERFORMANCE Electronic Throttle Control System - RL

Friday, June 05, 2009 2:29:49 PM

Page 46

18. Disconnect the throttle actuator control module 16P connector (see THROTTLE ACTUATOR

CONTROL MODULE REPLACEMENT ).

19. Check for continuity between throttle actuator control module 16P connector terminals No. 1 and No.

8 and C251 connector (13P) terminals No. 6 and No. 13 individually.

Fig. 59: Checking Continuity Between Throttle Actuator Control Module 16P Terminals 1 And
8 And C251 (13P) Terminals 6 And 13
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Go to step 29.

NO - Repair open in the wires between the throttle actuator control module and the C251 connector
(motor drive lines), then go to step 22.

20. Turn the ignition switch OFF.

21. Replace the throttle body (see THROTTLE BODY REMOVAL/INSTALLATION ).

22. Reconnect all connectors.

23. Turn the ignition switch ON (II).

24. Reset the PCM with the HDS.

25. Do the PCM idle learn procedure (see PCM IDLE LEARN PROCEDURE ).

26. Turn the ignition switch OFF.

27. Turn the ignition switch ON (II), and wait 10 seconds.

28. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P2176 indicated?

YES - Check for poor connections or loose terminals at the throttle body and the throttle actuator
control module, then clean the throttle body (see THROTTLE BODY CLEANING ), and go to step
1.

NO - Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, go to the
indicated DTCs troubleshooting.

2007 Acura RL

2005-08 ENGINE PERFORMANCE Electronic Throttle Control System - RL

Friday, June 05, 2009 2:29:49 PM

Page 47

29. Reconnect all connectors.

30. Update the PCM if it does not have the latest software (see UPDATING THE PCM ), or substitute a

known-good PCM (see SUBSTITUTING THE PCM ).

31. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P2176 indicated?

YES - Check for poor connections or loose terminals at the throttle body and the throttle actuator
control module. If the PCM was updated, substitute a known-good PCM (see SUBSTITUTING THE
PCM ), then recheck. If the PCM was substituted, go to step 1.

DTC P2552: THROTTLE ACTUATOR CONTROL MODULE RELAY MALFUNCTION

1. Turn the ignition switch ON (II).

2. Clear the DTC with the HDS.

3. Do the ETCS TEST in the INSPECTION MENU with the HDS.

Is the RELAY circuit OK?

YES - Intermittent failure, the system is OK at this time. Check for poor connections or loose
terminals at the throttle actuator control module relay, the throttle actuator control module, and the
PCM.

NO - Go to step 4.

4. Turn the ignition switch OFF.

5. Jump the SCS line with the HDS.

6. Remove the throttle actuator control module relay (A).

NOTE:

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

2007 Acura RL

2005-08 ENGINE PERFORMANCE Electronic Throttle Control System - RL

Friday, June 05, 2009 2:29:49 PM

Page 48

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