DTC Troubleshooting

Control System DTCs

DTC Troubleshooting: P0122

DTC P0122 : TP Sensor A Circuit Low Voltage

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information How To Troubleshoot The Fuel And Emissions Systems.

1. Problem verification:

Problem verification
-1. Turn the ignition switch to ON (II).

-2. Clear the DTC with the HDS.

-3. Check TP SENSOR A in the DATA LIST with the HDS.

Is there about 0.3 V or less?
-YES- The failure is duplicated. Go to step 2.
-NO- Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the throttle body and the ECM.

2. Determine possible failure area (VCC3 line, TH_1 line):

Determine possible failure area (VCC3 line, TH_1 line)
-1. Check for Pending or Confirmed DTCs with the HDS.

Are DTC P0122 and P0222 indicated at the same time?
-YES- Go to step 4.
-NO- Go to step 3.

3. Shorted wire check (TH_1 line):

Shorted wire check (TH_1 line)
-1. Turn the ignition switch to LOCK (0).

-2. Jump the SCS line with the HDS.

-3. Disconnect the following connectors.





-4. Check for continuity between test points 1 and 2.









Is there continuity?
-YES- Repair a short in the TH_1 wire between the ECM (C30) and the throttle body, then do the repair verification.
-NO- The TH_1 wire is OK. Update the ECM ECM/PCM Update if it does not have the latest software, or substitute a known-good ECM Service and Repair, then do the repair verification.

4. Determine possible failure area (VCC3 line, throttle body):

Determine possible failure area (VCC3 line, throttle body)
-1. Turn the ignition switch to LOCK (0).

-2. Disconnect the following connector.





-3. Turn the ignition switch to ON (II).

-4. Measure the voltage between test points 1 and 2.









Is there about 5.0 V?
-YES- Replace the throttle body Removal and Replacement, then do the repair verification.
-NO- Go to step 5.

5. Open wire check (VCC3 line):

Open wire check (VCC3 line)
-1. Turn the ignition switch to LOCK (0).

-2. Jump the SCS line with the HDS.

-3. Disconnect the following connector.





-4. Check for continuity between test points 1 and 2.









Is there continuity?
-YES- The VCC3 wire is OK. Update the ECM ECM/PCM Update if it does not have the latest software, or substitute a known-good ECM Service and Repair, then do the repair verification.
-NO- Repair an open in the VCC3 wire between the ECM (C22) and the throttle body, then do the repair verification.

Repair verification:

-1. Turn the ignition switch to LOCK (0).

-2. Reconnect all connectors.

-3. Turn the ignition switch to ON (II).

-4. Reset the ECM with the HDS How To Troubleshoot The Fuel And Emissions Systems.

-5. Do the ECM idle learn procedure. ECM/PCM Idle Learn Procedure

-6. Check for Pending or Confirmed DTCs with the HDS.

Is DTC P0122 indicated?
-YES- Check for poor connections or loose terminals at the throttle body and the ECM. If the ECM was updated, substitute a known-good ECM Service and Repair, then recheck. If the ECM was substituted, go to step 1.
-NO- Troubleshooting is complete. If the ECM was substituted, replace the original ECM Service and Repair. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.