Pinpoint Test I: Incorrect Oil Pressure Gauge Indication
Instrumentation, Message Center and Warning Chimes
Pinpoint Tests
Pinpoint Test I: Incorrect Oil Pressure Gauge Indication
Refer to Wiring Diagram Set 60, Instrument Cluster for schematic and connector information. 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. The IPC, 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 IPC 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
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 will result in false resistance readings. Refer to Battery.
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I1 CARRY OUT THE IPC TACHOMETER ACTIVE COMMAND USING THE SCAN TOOL
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: IPC DataLogger.
- Select the IPC oil pressure gauge (OIL_GAUGE) active command on and off while sweeping the oil pressure gauge.
- Does the oil pressure gauge sweeping to high (H) 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. REFER to Instrument Panel Cluster (IPC) Service and Repair. TEST the system for normal operation.
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I2 CHECK FOR A STUCK CLOSED ENGINE OIL PRESSURE SWITCH
- Ignition OFF.
- Disconnect: Engine Oil Pressure (EOP) SwitchC103.
- 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 (EOP) switch. REFER to Engine,
Engine or Engine. TEST the system for normal operation.
No
GO to I3.
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I3 CHECK THE OIL PRESSURE SIGNAL CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: IPC C220.
- Measure the resistance between the IPC 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.
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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.
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I5 CHECK THE PRESSURE SIGNAL CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: Negative Battery Cable.
- Disconnect: IPC C220.
- With the jumper wire in place, measure the resistance between the IPC 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.
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I6 CHECK THE OIL PRESSURE
- Carry out the engine oil pressure test. Refer to Engine. Oil Pressure Test
- Is the oil pressure within specification?
Yes
INSTALL a new Engine Oil Pressure (EOP) switch. REFER to Engine. TEST the system for normal operation.
No
REFER to Engine to continue diagnosis of the engine oil pressure.
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I7 CHECK FOR CORRECT IPC OPERATION
- Disconnect the IPC connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the IPC 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. REFER to Instrument Panel Cluster (IPC) Service and Repair. 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.
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