Pinpoint Test I: Incorrect Oil Pressure Gauge Indication
Instrumentation, Message Center and Warning Chimes
Pinpoint Test I: Incorrect Oil Pressure Gauge Indication
Refer to Wiring Diagram Set 60, Instrument Cluster for schematic and connector information [1][2]Diagrams By Number.
Normal Operation
The Instrument Panel Cluster (IPC) provides a reference voltage to the oil pressure switch. When the oil pressure is within normal ranges, the engine oil pressure switch closes to ground pulling the reference voltage low to the IPC (Instrument Panel Cluster). Upon receipt of the ground signal, the IPC (Instrument Panel Cluster) 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 IPC (Instrument Panel Cluster) 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
- IPC (Instrument Panel Cluster)
PINPOINT TEST I : THE OIL PRESSURE GAUGE IS INOPERATIVE
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
NOTE: Failure to disconnect the battery when instructed results in false resistance readings.
I1 CARRY OUT THE IPC (Instrument Panel Cluster) TACHOMETER ACTIVE COMMAND USING THE SCAN TOOL
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: IPC (Instrument Panel Cluster) DataLogger.
- Select the IPC (Instrument Panel Cluster) oil pressure gauge (OIL_GAUGE) active command. Command the oil pressure gauge on and off while monitoring the oil pressure gauge.
Does the oil pressure gauge sweep to the normal range when commanded on and return to low (L) when commanded off?
Yes
If the oil pressure gauge always reads in the normal range, GO to I2.
If the oil pressure gauge always reads low (L) and does not register any oil pressure, GO to I4.
No
INSTALL a new IPC (Instrument Panel Cluster). REFER to Instrument Panel Cluster (IPC) . TEST the system for normal operation.
I2 CHECK FOR A STUCK CLOSED ENGINE OIL PRESSURE SWITCH
- Ignition OFF.
- Disconnect: Engine Oil Pressure (EOP) Switch C103.
- Ignition ON.
- Observe the engine oil pressure gauge.
Does the engine oil pressure gauge indicate low (L) oil pressure?
Yes
INSTALL a new engine oil pressure switch. TEST the system for normal operation.
No
GO to I3.
I3 CHECK THE OIL PRESSURE SIGNAL CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: IPC (Instrument Panel Cluster) C220.
- Measure the resistance between the IPC (Instrument Panel Cluster) C220-5, CMC24 (GY), harness side and ground.
Is the resistance greater than 10,000 ohms?
Yes
GO to I7.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
I4 CHECK FOR A STUCK OPEN ENGINE OIL PRESSURE SWITCH
NOTE: If the fused jumper wire fails, repair circuit CMC24 (GY) for a short to voltage.
- Ignition OFF.
- Disconnect: Engine Oil Pressure Switch C103.
- Connect a fused jumper wire between the engine oil pressure switch C103-1, circuit CMC24 (GY), harness side and ground.
- Ignition ON.
Does the oil pressure gauge indicate normal?
Yes
REMOVE the jumper wire. GO to I6.
No
LEAVE the jumper wire connected. GO to I5.
I5 CHECK THE PRESSURE SIGNAL CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: Negative Battery Cable.
- Disconnect: IPC (Instrument Panel Cluster) C220.
- With the jumper wire in place, measure the resistance between the IPC (Instrument Panel Cluster) C220-5, circuit CMC24 (GY), harness side and ground.
Is the resistance less than 5 ohms?
Yes
REMOVE the jumper wire. GO to I7.
No
REMOVE the jumper wire. REPAIR the circuit. TEST the system for normal operation.
I6 CHECK THE OIL PRESSURE
- Carry out the engine oil pressure test. Oil Pressure Test
Is the oil pressure within specification?
Yes
INSTALL a new engine oil pressure switch. TEST the system for normal operation.
No
REFER to Engine to continue diagnosis of the engine oil pressure.
I7 CHECK FOR CORRECT IPC (Instrument Panel Cluster) OPERATION
- Disconnect the IPC (Instrument Panel Cluster) connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the IPC (Instrument Panel Cluster) connector and make sure it seats correctly.
- Operate the system and verify the concern is still present.
Is the concern still present?
Yes
INSTALL a new IPC (Instrument Panel Cluster). REFER to Instrument Panel Cluster (IPC) . TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. TEST the system for normal operation.