DTC P2123 (19-21 9-Speed A/T)

DTC P2123  : Accelerator Pedal Position (APP) Sensor A (Throttle Position (TP) Sensor D) Circuit High Voltage

NOTE:  Before you troubleshoot, review the general troubleshooting information - Refer to: How to Troubleshoot the Fuel and Emissions Systems .

DTC (PGM-FI)

1. Problem verification

   - 1. Turn the vehicle to the ON mode.

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

   Signal	Threshold		Current conditions
   	Values	Unit	Values	Unit
   APP SENSOR A	More than 4.9	V

   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.

   If the on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the on-board snapshot - Refer to: How to Troubleshoot the Fuel and Emissions Systems .

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

   - 1. Turn the vehicle to the OFF (LOCK) mode.

   - 2. Disconnect the following connector.

   APP sensor 6P connector

   - 3. Turn the vehicle to the ON mode.

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

   Test condition	Vehicle ON mode
   	APP sensor 6P connector: disconnected
   Test point 1	APP sensor 6P connector (female terminals) No. 4:
   Test point 2	APP sensor 6P connector (female terminals) No. 5:

   Courtesy of HONDA, U.S.A., INC.

   Is there about 5.0 V?

   YES 

   Replace the accelerator pedal module .

   NO 

   Go to step 3.

3. Open wire check (PGND line)

   - 1. Turn the vehicle to the OFF (LOCK) mode.

   - 2. Jump the SCS line with the HDS, and wait more than 1 minute.

   - 3. Disconnect the following connector.

   PCM connector A (50P)

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

   Terminal A	APP sensor 6P connector (female terminals) No. 5:
   Terminal B	Body ground

   Courtesy of HONDA, U.S.A., INC.

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

   Test condition	Vehicle OFF (LOCK) mode
   	APP sensor 6P connector: disconnected
   	APP sensor 6P connector No. 5: jumped to body ground
   	PCM connector A (50P): disconnected
   Test point 1	PCM connector A (50P) No. 37 - Refer to: PCM Connector for Inputs and Outputs (19-21 9-Speed A/T)
   Test point 2	Body ground

   Is there continuity?

   YES 

   The PGND wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM, then recheck. - Refer to:

   PCM Removal and Installation (19-21 9-Speed A/T)

   If DTC P2123 goes away and the PCM was substituted, replace the original PCM - Refer to:

   PCM Removal and Installation (19-21 9-Speed A/T) .

   NO 

   Repair an open in the PGND wire between the PCM (A37) and the APP sensor.