Pinpoint Test C: The Low Oil Pressure Warning Indicator Is Never/Always On
WARNING: This page is about a different car, the 2004 Ford Ranger. However, it is still accessible from the selected car via links, so may be relevant.
- C1 CHECK LOW OIL PRESSURE INDICATOR OPERATION
- Key in ON position.
- Monitor the low oil pressure warning indicator.
- Start the engine and monitor the low oil pressure warning indicator.
- Does the low oil pressure warning indicator operate correctly?
- Yes : The system is OK.
- No
: If the low oil pressure warning indicator is inoperative, GO to C2.
If the low oil pressure warning indicator is always on, GO to C3.
- C2 CHECK FOR A STUCK CLOSED OIL PRESSURE SWITCH
- Key in OFF position.
- Disconnect: Oil Pressure Switch C103.
- Key in ON position.
- Is the low oil pressure warning indicator on?
- Yes : INSTALL a new oil pressure switch. REFER to FUEL CHARGING & CONTROLS - 2.3L , FUEL CHARGING & CONTROLS - 3.0L (2V) or FUEL CHARGING & CONTROLS - 4.0L SOHC . TEST the system for normal operation.
- No : GO to C5.
- C3 CHECK A FOR STUCK OPEN OIL PRESSURE SWITCH
- Key in OFF position.
- Disconnect: Oil Pressure Switch C103.
- Key in ON position.
- Connect a fused jumper wire (10A) between the oil pressure switch C103, circuit 253 (DG/WH), harness side and ground.
- Is the low oil pressure warning indicator on?
- Yes : GO to C7.
- No : REMOVE the jumper wire. GO to C4.
- C4 CHECK CIRCUIT 253 (DG/WH) FOR AN OPEN
- Key in OFF position.
- Disconnect: Instrument Cluster C220a.
- Measure the resistance between the instrument cluster C220a pin 7, circuit 253 (DG/WH), harness side and the oil pressure switch C103, circuit 253 (DG/WH), harness side.
- Is the resistance less than 5 ohms?
- Yes : GO to C6.
- No : REPAIR the circuit. TEST the system for normal operation.
- C5 CHECK CIRCUIT 253 (DG/WH) FOR A SHORT TO GROUND
- Key in OFF position.
- Disconnect: Instrument Cluster C220a.
- Measure the resistance between the instrument cluster C220a pin 7, circuit 253 (DG/WH), harness side and ground.
- Is the resistance greater than 10,000 ohms?
- Yes : GO to C6.
- No : REPAIR the circuit. TEST the system for normal operation.
- C6 CHECK FOR CORRECT INSTRUMENT CLUSTER OPERATION
- Disconnect all the instrument cluster connectors.
- Check for:
- Corrosion
- Pushed-out pins
- Connect all the instrument cluster connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
- Yes : INSTALL a new instrument cluster. REFER to INSTRUMENT CLUSTER . 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.
- C7 CARRY OUT THE OIL PRESSURE TEST
- Carry out the oil pressure test. REFER to ENGINE SYSTEM-GENERAL INFORMATION .
- Is the oil pressure within specification?
- Yes : INSTALL a new oil pressure switch. REFER to ENGINE 2.3L , ENGINE 3.0L (2V) or ENGINE 4.0L SOHC . TEST the system for normal operation.
- No : REFER to ENGINE SYSTEM-GENERAL INFORMATION to continue diagnosis of the engine oil system.