Engine Oil Level Sensor/Switch Diagnosis

Refer to Engine Controls Schematic IAC PCM ENG OIL LVL Engine Oil Pressure.

Diagnostic Chart:

CIRCUIT DESCRIPTION
The Engine Oil Level (EOL) switch is a simple float switch that is grounded when the engine oil level is OK. The PCM tests the EOL switch circuit at startup. Before checking the state of the EOL switch, the PCM performs a test routine based on time and Engine Coolant Temperature (ECT) to ensure that the engine oil has drained back into the sump. To test for low oil level at start-up, one of the following conditions must be present:
^ The ECT must be more than 15°C (59°F)
^ The ECT at key ON must be at least 12°C (22°F) cooler than the ECT at the last key OFF.

The low oil level lamp will be illuminated for about a minute when the PCM tests for low oil level and the EOL switch indicates that a low oil level condition exists (EOL switch circuit not grounded). When the ignition is first turned ON, the IP Cluster commands the low oil level lamp ON for a brief period of time to test the bulb.

DIAGNOSTIC AIDS
Inspect for the following conditions:

IMPORTANT: Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.

^ Poor terminal connection-Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Use a corresponding mating terminal to test for proper tension.
^ Damaged harness-Inspect the wiring harness for damage. If the harness inspection does not reveal a problem, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the scan tool display may indicate the location of the fault.
^ PCM and engine grounds for clean and secure connections

If the DTC is determined to be intermittent, reviewing the Failure Records can be useful in determining when the DTC was last set.

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table:
11. This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed.
12. For the PCM to test engine oil level, start-up ECT must be at least 12°C (22°F) cooler than the ECT was last time the ignition was turned off. Allowing the engine to warm and then cool ensures that the PCM tests the engine oil level switch and that the information displayed on the scan tool is current.