DTC P0643: Sensor Reference Voltage A Circuit High Voltage

1. Turn the ignition switch ON (II).

1. Clear the DTC with the HDS.

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

Is DTC P0643 indicated?

YES | - | Go to Step 4 .
NO | - | Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the FRP sensor, the MAF/IAT sensor, the MAP/IAT sensor, the APP sensor and the ECM.■

1. Turn the ignition switch OFF, and wait 30 seconds.

1. Disconnect ECM connectors No. 1 (96P) and No. 2 (58P).

1. Turn the ignition switch ON (II).

1. Measure voltage between body ground and ECM connector No. 1 terminals No. 8, No. 9, No. 33 and ECM connector No. 2 terminal No. 14 individually.

Is there battery voltage?

YES | - | Repair short to power in the wire between the ECM connector terminals and these sensors, then go to Step 18 .

- FRP sensor and ECM connector No. 1 terminal No. 9
- MAF/IAT sensor and ECM connector No. 1 terminal No. 8
- MAP/IAT sensor and ECM connector No. 1 terminal No. 33
- APP sensor and ECM connector No. 2 terminal No. 14

NO | - | Go to Step 8 .

1. Turn the ignition switch OFF.

1. Disconnect the connectors from these sensors:
   - FRP sensor
   - MAF/IAT sensor
   - MAP/IAT sensor
   - APP sensor