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).