With M/T

DTC Troubleshooting: P15C4 (118)

DTC P15C4:

Auto Idle Stop System Malfunction (M/T model)

NOTE:

- Before you troubleshoot, record all freeze data, and any on-board snapshot, and review the general troubleshooting information Initial Inspection and Diagnostic Overview.
- If the DTC cannot be cleared, do the troubleshooting for DTC U1204.
- This DTC is stored when the auto idle stop is prohibited due to failure.

1. Check the AUTO IDLE STOP DOES NOT OCCUR (BRAKE) in the PGM-FI SYSTEM DATA LIST with the HDS.

Does the HDS indicate EXIST?

YES -

Go to the brake booster pressure monitoring system's general troubleshooting information Initial Inspection and Diagnostic Overview. When the brake booster pressure monitoring system troubleshooting is completed, reset the ECM then clear the DTC in the IMA system.

NO -

Go to step 2.

2. Check the AUTO IDLE STOP DOES NOT OCCUR (A/C) in the PGM-FI SYSTEM DATA LIST with the HDS.

Does the HDS indicate EXIST?

YES -

Go to the climate control system's general troubleshooting information Initial Inspection and Diagnostic Overview. When the climate control system troubleshooting is completed, reset the ECM then clear the DTC in the IMA system.

NO -

Go to step 3.

3. Check the AUTO IDLE STOP DOES NOT OCCUR (NP SWITCH) in the PGM-FI SYSTEM DATA LIST with the HDS.

Does the HDS indicate EXIST?

YES -

Go to step 5.

NO -

Go to step 4.

4. Check the AUTO IDLE STOP DOES NOT OCCUR (CLUTCH PEDAL POSITION SWITCH) in the PGM-FI SYSTEM DATA LIST with the HDS.

Does the HDS indicate EXIST?

YES -

Go to step 26.

NO -

Intermittent failure, the system is OK at this time. Reset the ECM, then clear the DTC in the IMA system.

5. Check the NP SWITCH in the PGM-FI DATA LIST with the HDS.

Does the HDS indicate ON when you move the shift lever to neutral, and does it indicate OFF when you move the shift lever to 1st or 2nd gear?

YES -

Intermittent failure, the neutral position switch is OK at this time. Reset the ECM, and clear the DTC in the IMA system.

NO -

- If the neutral position switch stays ON, go to step 6.
- If the neutral position switch stays OFF, go to step 13.
- If the indication is unstable, check the neutral position switch and the shift arm condition M/T Change Lever Assembly Disassembly/Reassembly, then go to step 67.

6. Turn the ignition switch to LOCK (0).

7. Disconnect the neutral position switch 2P connector.

8. Check the NP SWITCH in the PGM-FI DATA LIST with the HDS with the shift lever in neutral.

Does the NP SWITCH indicate OFF?

YES -

Replace the neutral position switch Service and Repair, then go to step 67.

NO -

Go to step 9.

9. Turn the ignition switch to LOCK (0).

10. Jump the SCS line with the HDS.

11. Disconnect ECM connector B (44P).

12. Check for continuity between neutral position switch 2P connector terminal No. 2 and body ground.

Is there continuity?

YES -

Repair a short in the wire between the ECM (B13 and B21) and the neutral position switch, then go to step 67.

NO -

Update the ECM if it does not have the latest software ECM/PCM Update, then recheck. If the ECM was updated, replace the original ECM Service and Repair, then recheck.

13. Turn the ignition switch to ON (II).

14. Disconnect the neutral position switch 2P connector.

15. Connect neutral position switch 2P connector terminal No. 2 to body ground with a jumper wire.

16. Check the NP SWITCH in the PGM-FI DATA LIST with the HDS.

Does the HDS indicate ON?

YES -

Go to step 17.

NO -

Go to step 21.

17. Disconnect the jumper wire from the neutral position switch 2P connector.

18. Turn the ignition switch to ON (II).

19. Connect neutral position switch 2P connector terminals No. 1 and No. 2 with a jumper wire.

20. Check the NP SWITCH in the PGM-FI DATA LIST with the HDS with the shift lever in neutral.

Does the HDS indicate OFF?

YES -

Repair an open in the wire between the neutral position switch and G101, then go to step 67.

NO -

Replace the neutral position switch Service and Repair, then go to step 67.

21. Disconnect the jumper wire from the neutral position switch 2P connector.

22. Turn the ignition switch to LOCK (0).

23. Jump the SCS line with the HDS.

24. Disconnect ECM connector B (44P).

25. Check for continuity between these terminals:

- ECM connector terminal B13 and neutral position switch 2P connector terminal No. 2.
- ECM connector terminal B21 and neutral position switch 2P connector terminal No. 2.

Is there continuity?

YES -

Update the ECM if it does not have the latest software ECM/PCM Update, then recheck. If the ECM was updated, replace the original ECM Service and Repair, then recheck.

NO -

Repair an open in the wire between the neutral position switch and the ECM (B13 or B21), then go to step 67.

26. Check CLUTCH PEDAL POSITION SWITCH A and CLUTCH PEDAL POSITION SWITCH A (C) in the PGM-FI DATA LIST with the HDS.

Do the HDS indicate CLOSE when the clutch pedal is pressed and OPEN when the clutch pedal is released?

YES -

Intermittent failure, the system is OK at this time. Reset the ECM, and clear the DTC in the IMA system.

NO -

- If clutch pedal position switch A CLOSE stays on, go to step 27.
- If clutch pedal position switch A OPEN stays on, go to step 34.
- If clutch pedal position switch C CLOSE stays on, go to step 47.
- If clutch pedal position switch C OPEN stays on, go to step 54.
- If clutch pedal position switch A and clutch pedal position switch C OPEN stays on, repair an open in the wire between clutch pedal position switch A and C and G403, then go to step 67.

27. Turn the ignition switch to LOCK (0).

28. Disconnect the clutch pedal position switch A 2P connector.

29. Check CLUTCH PEDAL POSITION SWITCH A in the PGM-FI DATA LIST with the HDS.

Does the HDS indicate OPEN?

YES -

Replace clutch pedal position switch A Service and Repair, then go to step 67.

NO -

Go to step 30.

30. Turn the ignition switch to LOCK (0).

31. Jump the SCS line with the HDS.

32. Disconnect ECM connector B (44P).

33. Check for continuity between clutch pedal position switch A 2P connector terminal No. 1 and body ground.

Is there continuity?

YES -

Repair a short in the wire between the ECM (B12) and clutch pedal position switch A, then go to step 67.

NO -

Update the ECM if it does not have the latest software ECM/PCM Update, then recheck. If the ECM was updated, replace the original ECM Service and Repair, then recheck.

34. Turn the ignition switch to LOCK (0).

35. Disconnect clutch pedal position switch A 2P connector.

36. Connect clutch pedal position switch A 2P connector terminal No. 1 to body ground with jumper wire.

37. Check CLUTCH PEDAL POSITION SWITCH A in the PGM-FI DATA LIST with the HDS.

Does the HDS indicate CLOSE?

YES -

Go to step 38.

NO -

Go to step 42.

38. Disconnect the jumper wire from the clutch pedal position switch A 2P connector.

39. Turn the ignition switch to LOCK (0).

40. Connect clutch pedal position switch A 2P connector terminals No. 1 and No. 2 with a jumper wire.

41. Check CLUTCH PEDAL POSITION SWITCH A in the PGM-FI DATA LIST with the HDS.

Does the HDS indicate OPEN?

YES -

Repair an open in the wire between clutch pedal position switch A and G403, then go to step 67.

NO -

Replace clutch pedal position switch A Service and Repair, then go to step 67.

42. Disconnect the jumper wire from the clutch pedal position switch A 2P connector.

43. Turn the ignition switch to LOCK (0).

44. Jump the SCS line with the HDS.

45. Disconnect ECM connector B (44P).

46. Check for continuity between clutch pedal position switch A 2P connector terminal No. 1 and ECM connector terminal B12.

Is there continuity?

YES -

Repair a short in the wire between the ECM (B39) and clutch pedal position switch C, then go to step 67.

NO -

Update the ECM if it does not have the latest software ECM/PCM Update, then recheck. If the ECM was updated, replace the original ECM Service and Repair, then recheck.

54. Turn the ignition switch to LOCK (0).

55. Disconnect the clutch pedal position switch C 2P connector.

56. Connect clutch pedal position switch C 2P connector terminal No. 1 to body ground with a jumper wire.

57. Check CLUTCH PEDAL POSITION SWITCH A (C) in the PGM-FI DATA LIST with the HDS.

Does the HDS indicate CLOSE?

YES -

Go to step 58.

NO -

Go to step 62.

58. Disconnect the jumper wire from the clutch pedal position switch C 2P connector.

59. Turn the ignition switch to LOCK (0).

60. Connect clutch pedal position switch C 2P connector terminals No. 1 and No. 2 with a jumper wire.

61. Check CLUTCH PEDAL POSITION SWITCH A (C) in the PGM-FI DATA LIST with the HDS.

Does the HDS indicate OPEN?

YES -

Repair an open in the wire between clutch pedal position switch C and G403, then go to step 67.

NO -

Replace clutch pedal position switch C Service and Repair, then go to step 67.

62. Disconnect the jumper wire from the clutch pedal position switch C 2P connector.

63. Turn the ignition switch to LOCK (0).

64. Jump the SCS line with the HDS.

65. Disconnect ECM connector B (44P).

66. Check for continuity between clutch pedal position switch C 2P connector terminal No. 1 and ECM connector terminal B39.