Diagnostic Aids
P0641
The 5 V reference 1 circuit provides 5 V circuits to the following sensors:
- Air conditioning (A/C) refrigerant pressure sensor
- Exhaust and intake camshaft position sensors
- Fuel tank pressure sensor
- Multifunction intake air sensor
P0651
The 5 V reference 2 circuit provides 5 V circuits to the following sensors:
- Brake pedal position sensor (automatic transmission)
- Clutch pedal position sensor (manual transmission)
- Crankshaft position sensor
- Secondary air injection pressure sensor, if equipped
- Vehicle speed sensor (manual transmission)
P0697
The 5 V reference 3 circuit provides 5 V circuits to the following sensors:
- Accelerator pedal position sensor 2
- Manifold absolute pressure sensor
P06A3
The 5 V reference 4 circuit provides 5 V circuits to the following sensors:
- Accelerator pedal position sensor 1
- Throttle position sensor 1 and 2
It may be possible to locate the fault by disconnecting one component at a time from the affected 5 V reference circuit while viewing the 5 V Reference Circuit Status parameter on the scan tool. The scan tool parameter will change from Malfunction to OK when the source of the fault is disconnected. If all 5 V reference components have been disconnected and a fault is still indicated, the fault may exist in the wiring harness.