Pinpoint Test Y: The Low Oil Pressure Message Center Warning Indicator Is Never/Always On
Instrumentation, Message Center and Warning Chimes
Pinpoint Tests
Pinpoint Test Y: The Low Oil Pressure Message Center Warning Indicator Is Never/Always On
Refer to Wiring Diagram Set 60, Instrument Cluster for schematic and connector information. Diagrams By Number
Normal Operation
The Instrument Cluster (IC) uses engine rpm data, sent from the PCM over the High Speed Controller Area Network (HS-CAN) communication bus, to determine whether the engine is running. The engine oil pressure switch is hardwired to the IC through oil pressure input circuit. The IC provides a reference voltage to the engine oil pressure switch when the ignition key is in the RUN position. When there is low or no oil pressure, the engine oil pressure switch remains open, the IC detects no change in the reference voltage, and the low oil pressure message center warning indicator is turned on. When the engine is running with sufficient oil pressure, the PCM sends an rpm status message to the IC and the engine oil pressure switch closes, providing a ground, which pulls the reference voltage from the IC low, turning off the low oil pressure message center warning indicator. If the engine rpm status message is missing or if the data is deemed invalid by the IC for greater than 5 seconds, the IC sets DTC U0100 and defaults the low oil pressure message center warning indicator on.
NOTE: If DTC U0100 is set in the IC other symptoms may also be present such as an inoperative speedometer, tachometer or temperature gauge.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Engine oil pressure switch
- Base engine concern
- Message center concern
PINPOINT TEST Y: THE LOW OIL PRESSURE MESSAGE CENTER WARNING INDICATOR IS NEVER/ALWAYS ON
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
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Y1 CHECK THE DOOR AJAR MESSAGE CENTER WARNING INDICATOR
- Close all doors, liftgate and liftgate glass.
- Ignition ON.
- Open the driver door while monitoring the door ajar message center warning indicator.
- Does the driver door ajar message center warning indicator turn off with the driver door closed and turn on with the driver door open?
Yes
GO to Y2.
No
GO to Pinpoint Test A. Pinpoint Test A: The Instrument Cluster (IC) Is Inoperative
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Y2 CHECK THE TACHOMETER OPERATION
- Start the engine and monitor the tachometer.
- Does the tachometer operate correctly?
Yes
GO to Y3
No
GO to Pinpoint Test J. Pinpoint Test J: Inaccurate Tachometer Indication
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Y3 RETRIEVE THE RECORDED DTCs FROM THE IC SELF-TEST
- Check for recorded IC DTCs from the self-test.
- Is DTC U0100 recorded?
Yes
GO to Pinpoint Test AT. Pinpoint Tests AT: DTC U0100
No
GO to Y4.
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Y4 RETRIEVE THE RECORDED DTCs FROM THE PCM KOEO SELF-TEST
- Check for recorded PCM DTCs from the Key ON Engine OFF (KOEO) self-test.
- Are any DTCs recorded?
Yes
REFER to Computers and Control Systems Information.
No
If the low oil pressure message center warning indicator is never on, GO to Y5.
If the low oil pressure message center warning indicator is always on, GO to Y7.
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Y5 CHECK FOR A STUCK CLOSED ENGINE OIL PRESSURE SWITCH
- Ignition OFF.
- Disconnect: Engine Oil Pressure Switch C103 .
- Start the engine.
- Observe the low oil pressure message center warning indicator.
- Does the low oil pressure message center warning indicator turn off?
Yes
INSTALL a new Engine Oil Pressure (EOP) switch. REFER to Engine. TEST the system for normal operation.
No
GO to Y6.
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Y6 CHECK THE OIL PRESSURE INPUT CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: IC C220 .
- Measure the resistance between the IC C220-18, circuit CMC24 (GY), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to Y11.
No
REPAIR circuit CMC24 (GY) for a short to ground. TEST the system for normal operation.
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Y7 CHECK FOR A STUCK OPEN ENGINE OIL PRESSURE SWITCH
- 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.
- Start the engine.
- Observe the low oil pressure message center warning indicator.
- Does the low oil pressure message center warning indicator turn off?
Yes
REMOVE the jumper wire. GO to Y10.
No
REMOVE the jumper wire. GO to Y8.
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Y8 CHECK THE OIL PRESSURE INPUT CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: IC C220 .
- Ignition ON.
- Measure the voltage between the IC C220-18, circuit CMC24 (GY), harness side and ground.
- Is any voltage present?
Yes
REPAIR circuit CMC24 (GY) for a short to ground. TEST the system for normal operation.
No
GO to Y9.
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Y9 CHECK THE OIL PRESSURE INPUT CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: IC C220 .
- Measure the resistance between the IC C220-18, circuit CMC24 (GY), harness side and the engine oil pressure switch C103-1, circuit CMC24 (GY), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to Y11.
No
REPAIR circuit CMC24 (GY) for a short to ground. TEST the system for normal operation.
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Y10 CHECK THE OIL PRESSURE
- Carry out the engine oil pressure test. Refer to Engine.
- 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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Y11 CHECK FOR CORRECT IC OPERATION
- Disconnect the IC connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the IC 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 IC. REFER to Instrument Cluster (IC) Instrument Cluster (IC). 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.
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