DTC P1623: ECM Power Source Circuit Unexpected Voltage

1. Turn the ignition switch ON (II).

1. Clear the DTC with the HDS.

1. Turn the ignition switch OFF, and wait 1 minute.

1. Turn the ignition switch ON (II).

1. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P1536 or P1623 indicated?

YES | - | Go to Step 6 .
NO | - | Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at PGM-FI main relay 1 and the ECM.■

1. Turn the ignition switch OFF.

1. Disconnect PGM-FI main relay 1.

1. Check PGM-FI main relay 1.

Is PGM-FI main relay 1 OK?

YES | - | Go to Step 9 .
NO | - | Replace PGM-FI main relay 1, then go to Step 13 .

1. Disconnect ECM connector No. 2 (58P).

1. Check for continuity between ECM connector No. 2 terminal No. 19 and body ground.

Is there continuity?

YES | - | Repair short in the wire between PGM-FI main relay 1 and ECM connector No. 2 terminal No. 19, then go to Step 12 .
NO | - | Go to Step 11 .