Diagnostic Aids

P0641 

The 5V reference 1 circuit provides 5 V to the sensors listed below:

• A/C refrigerant pressure sensor
• All four camshaft position sensors
• Fuel rail pressure sensor
• Fuel tank pressure sensor
• Multifunction intake air sensor, LFX without turbocharger
• Turbocharger boost/intake air temperature sensor, LF3 with turbocharger

P0651 

The 5V reference 2 circuit provides 5 V to the sensors listed below:

• Barometric pressure sensor, LF3 with turbocharger
• Brake pedal position sensor
• Crankshaft position sensor
• Multifunction intake air sensor, LF3 with turbocharger

P0697 

The 5V reference 3 circuit provides 5 V to the sensors listed below:

• Accelerator pedal position sensor 2
• Manifold absolute pressure (MAP) sensor

P06A3 

The 5V reference 4 circuit provides 5 V 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.