P0122
DTC P0122: TP Sensor Circuit Low Voltage1. 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).
5. Check for Temporary DTCs or DTCs with the HDS.
Are DTC P0107, P0122, and P0452 indicated at the same time?
YES - Go to step 20.
NO - Go to step 6.
6. Check the TP SENSOR in the DATA LIST with the HDS.
Is there about 0.5 V when the throttle is fully closed, and about 4.5 V when the throttle is fully opened?
YES - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the TP sensor and the ECM/PCM.
NO - Go to step 7.
7. Turn the ignition switch OFF.
8. Disconnect the TP sensor 3P connector.
9. Turn the ignition switch ON (II).
10. On the wire harness side, measure voltage between TP sensor 3P connector terminals No.1 and No.3.
Is there about 5 V?
YES - Go to step 11.
NO - Go to step 19.
11. Turn the ignition switch OFF.
12. On the sensor side, measure resistance between TP sensor 3P connector terminals No.1 and No.2 with the throttle fully closed.
Is there about 0.5 - 0.9 kOhms?
YES - Go to step 13.
NO - Go to step 29.
13. On the sensor side, measure resistance between TP sensor 3P connector terminals No.2 and No.3 with the throttle fully closed.
Is there about 5.0 kOhms?
YES - Go to step 14.
NO - Go to step 29.
14. Jump the SCS line with the HDS.
15. Disconnect ECM/PCM connector A (31P).
16. On the wire harness side, check for continuity between TP sensor 3P connector terminal No.2 and body ground.
Is there continuity?
YES - Repair short in the wire between the TP sensor and ECM/PCM (A29), then go to step 30.
NO - Go to step 17
17. Connect ECM/PCM connector terminal A29 to body ground with a jumper wire.
18. On the wire harness side, check for continuity between TP sensor 3P connector terminal No.2 and body ground.
Is there continuity?
YES - Go to step 34.
NO - Repair open in the wire between the TP sensor and ECM/PCM (A29), then go to step 30.
19. Measure voltage between ECM/PCM connector terminals A20 and A23.
Is there about 5 V?
YES - Repair open in the wire between the ECM/PCM (A20) and the TP sensor, then go to step 30.
NO - Go to step 35.
20. Turn the ignition switch OFF.
21. Jump the SCS line with the HDS.
22. Disconnect ECM/PCM connectors A (31P) and E (31P).
23. Disconnect the connectors from these parts:
- MAP sensor
- TP sensor
- FTP sensor
- EGR valve
- Input shaft (mainshaft) speed sensor
- Output shaft (countershaft) speed sensor
24. Check for continuity between body ground and ECM/PCM connector terminals A20, A21, and E5 individually.
Is there continuity?
YES - Repair short in the wire between the ECM/PCM (A20, A21, or E5) and each disconnected part, then go to step 30.
NO - Go to step 25.
25. Reconnect ECM/PCM connectors A (31P) and E (31P).
26. Turn the ignition switch ON (II).
27. Measure voltage between ECM/PCM connector terminal A21 and body ground.
Is there about 5 V?
YES - Go to step 28.
NO - Go to step 35.
28. Continue to monitor voltage at ECM/PCM connector terminal A21 while reconnecting these parts, one at a time:
- MAP sensor
- TP sensor
- FTP sensor
- EGR valve
- Input shaft (mainshaft) speed sensor
- Output shaft (countershaft) speed sensor
Did the voltage drop to about 0 V?
YES - Replace the part that caused the voltage to drop, then go to step 30.
NO - Go to step 35.
29. Replace the throttle body.
30. Reconnect all connectors.
31. Turn the ignition switch ON (II).
32. Reset the ECM/PCM with the HDS.
33. Do the ECM/PCM idle learn procedure. Programming and Relearning
34. Check for Temporary DTCs or DTCs with the HDS.
Are any Temporary DTCs or DTCs indicated?
YES - If DTC P0122 is indicated, check for poor connections or loose terminals at the TP sensor 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 - Troubleshooting is complete.
35. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM.
36. Check for Temporary DTCs or DTCs with the HDS.
Are any Temporary DTCs or DTCs indicated?
YES - If DTC P0122 is indicated, check for poor connections or loose terminals at the TP sensor 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.