Diagnostic Aids
The 5V reference 1 circuit provides 5 V to the sensors listed below:
- Air conditioning (A/C) refrigerant pressure sensor
- Exhaust and intake camshaft position sensors
- Manifold absolute pressure/air temperature sensor
- Fuel pressure sensor
The 5V reference 2 circuit provides 5 V to the sensors listed below:
- Engine oil pressure sensor
- Crankshaft position sensor
- Brake pedal position sensor
- Brake booster vacuum sensor
- Turbocharger boost sensor
The 5V reference 3 circuit provides 5 V to the accelerator pedal position sensor 2.
The 5V reference 4 circuit provides 5 V to the sensors listed below:
- Accelerator pedal position sensor 1
- Throttle position sensor
The 5V reference 5 circuit provides 5 V to the sensors listed below:
- Fuel rail pressure sensor
- Multifunction intake air sensor
- Fuel tank pressure 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.