Diagnostic Aids
- The 5-volt reference 1 bus provides 5 volts to the following sensors:
- The manifold absolute pressure (MAP) sensor
- The fuel tank pressure (FTP) sensor
- The accelerator pedal position (APP) sensor 2
- The air injector reaction (AIR) pressure sensor, if equipped
- The engine oil pressure (EOP) switch
- The air conditioning (A/C) refrigerant pressure sensor
- The camshaft position (CMP) sensor
- The 5-volt reference 2 bus provides 5 volts to the following sensors:
- The APP sensor 1
- The throttle position (TP) sensor 1 and 2
- The crankshaft position (CKP) sensor
- It may be possible to locate the fault by disconnecting one component at a time from the affected 5-volt reference circuit while viewing the 5-Volt Reference circuit status parameter on the scan tool. The scan tool parameter will change from Fault to OK when the source of the fault is disconnected. If all 5-volt reference components have been disconnected and a fault is still indicated, the fault may exist in the wiring harness.