DTC Troubleshooting

Control System DTCs

DTC Troubleshooting: P2128

DTC P2128 : APP Sensor B (TP Sensor E) Circuit High 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:

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

-2. Check the parameter(s) below with the HDS.






Do the current condition(s) match the threshold?
-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 APP sensor and the PCM.

2. Determine possible failure area (APP sensor, others):

-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 APP sensor Service and Repair, then do the repair verification.
-NO- There is a problem in the SG5 line. Go to step 3.

3. Open wire check (SG5 line):

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

-2. Jump the SCS line with the HDS.

-3. Disconnect the following connector.






-4. Connect terminals A and B with a jumper wire.










-5. Check for continuity between test points 1 and 2.










Is there continuity?
-YES- The SG5 wire is OK. Update the PCM PCM Update if it does not have the latest software, or substitute a known-good PCM Service and Repair, then do the repair verification.
-NO- Repair an open in the SG5 wire between the PCM (A45) and the APP sensor, 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 PCM with the HDS How to Troubleshoot the Fuel And Emissions Systems.

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

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

Is DTC P2128 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 Service and Repair, then recheck. If the PCM was substituted, go to step 1.
-NO- Troubleshooting is complete. If the PCM was substituted, replace the original PCM Service and Repair. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.