Engine Oil Level Sensor/Switch Diagnosis

Diagnostic Chart:

Schematic:

CIRCUIT DESCRIPTION
The engine oil level switch is a simple float switch that is grounded when the engine oil level is OK. The Powertrain Control Module (PCM) checks the engine oil level switch circuit at start-up. Before checking the state of the engine oil level 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, both 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 engine coolant temperature at the last key OFF.

DIAGNOSTIC AIDS
For diagnosis of the instrument panel, perform the System Check in the Instrument Cluster section of Electrical Diagnosis. Refer to A Diagnostic System Check - Instrument Cluster in Instrument Panel, Gauges & Console. Instrument Panel, Gauges and Warning Indicators

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. Refer to Diagrams.
^ 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. Refer to Diagrams.
^ 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.