DTC Troubleshooting: P2123 (37)
DTC P2123:
 APP Sensor A Circuit High Voltage
NOTE: Before you troubleshoot, record all freeze data and review the general troubleshooting information.
  1. Turn the ignition switch ON (II).
  1. Check the APP SENSOR A in the DATA LIST with the Honda PGM tester or the HDS.
Is there about 4.8 V or higher?
YES -
Go to Step 3 .
NO -
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at APP sensor A and at the ECM.■
  1. Turn the ignition switch OFF.
  1. Disconnect the APP sensor 6P connector.
  1. Turn the ignition switch ON (II).
  1. Measure voltage between APP sensor 6P connector terminals No. 2 and No. 3.
Is there about 5 V?
YES -
Go to Step 10 .
NO -
Go to Step 7 .
  1. Turn the ignition switch OFF, and wait 2 minutes.
  1. Disconnect ECM connector No. 2 (58P).
  1. Check for continuity between ECM connector No.2 terminal No. 12 and APP sensor 6P connector terminal No.2.
Is there continuity?
YES -
Go to Step 16 .
NO -
Repair open in the wire between APP sensor A and ECM connector No. 2 terminal No. 12, then go to Step 12 .
  1. Turn the ignition switch OFF.
  1. Reconnect all connectors.
  1. Turn the ignition switch ON (II).
  1. Reset the ECM with the HDS.
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P2123 indicated?
YES -
Check for poor connections or loose terminals at APP sensor A and the ECM, then go to Step 1 .
NO -
Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.■
  1. Reconnect all connectors.
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P2123 indicated?
YES -
Check for poor connections or loose terminals at APP sensor A and the ECM. If the ECM was updated, substitute a known-good ECM, then recheck. If the ECM was substituted, go to Step 1 .
NO -
If the ECM was updated, troubleshooting is complete. If the ECM was substituted, replace the original ECM. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.■