Test D: The Oil Pressure Gauge Is Inoperative

PINPOINT TEST D: THE OIL PRESSURE GAUGE IS INOPERATIVE

Normal Operation
The instrument cluster (IC) provides a reference voltage to the oil pressure switch on circuit 31 (WH/RD) (gasoline) or circuit 1308 (BN/OG) (diesel). When the oil pressure is within normal ranges, the engine oil pressure switch closes to ground pulling the reference voltage low to the instrument cluster (IC). The instrument cluster (IC), upon receipt of the ground signal, commands the oil pressure gauge to the normal or mid-range position. When the oil pressure is low, the engine oil pressure switch opens, removing the ground, and the instrument cluster (IC) commands the oil pressure gauge to the L (low) position.

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Engine oil pressure switch
- Base engine concern
- Instrument cluster (IC)

D1:

D2-D4:

D5-D7: