"CHECK OIL LEVEL" Message

Circuit Description

The PCM monitors the engine oil level through the oil level switch input, pin '2D6'. The oil level switch is a magnetic switch that is closed with normal oil level and opens when oil level drops approximately 2 quarts below full. When the switch is closed, the PCM will see a low voltage on pin '2D6' and when the switch is open, it will see a high voltage. The PCM will only check for a low oil level when it 'wakes up' and sees a drop in coolant temperature of at least 15°C since the end of the previous ignition cycle. This is done to assure that the oil has had a chance to drain back into the oil pan so that a correct oil level reading may be made. If these conditions are met and the oil level input is high, indicating low oil level, the PCM will send the 'CHECK OIL LEVEL' message to the DIC.

Test Condition(s)

1. None.

Failure Condition(s)

1. Engine Coolant Temperature (ECT) sensor not failed.
2. Change in engine coolant temperature since last ignition cycle is greater than 15°C.
3. Oil level input high, indicating low oil level.

Action Taken

Display 'CHECK OIL LIFE' message on the DIC.

Diagnosis

Condition Possible Causes
Erroneous Message Open in CKT 114, open in
switch, or open in CKT 450

No Message Short to ground on CKT 114
or shorted switch