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