P1189 CADILLAC Possible Causes
- Faulty engine oil pressure switch
- Engine oil pressure switch harness is open or shorted
- Poor electrical connection in the engine oil pressure switch circuit
How to Fix P1189 CADILLAC Code?
Start by checking the “possible causes” listed above. Visually inspect the corresponding wiring harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.
Possible Symptoms
- Engine light on (or engine service warning light soon)
P1189 CADILLAC Meaning
The low oil pressure sensor is normally closed. When oil pressure rises above 1 to 4.5 psi, the switch contacts open. The Powertrain Control Module (PCM) provides 12 volts to the oil pressure input circuit. With low oil pressure, the 12 volts are pulled to ground. This diagnostic tests for an open condition in the oil pressure switch circuit. If the engine has been stopped long enough for engine temperature to drop by 10°C, a short circuit (low oil pressure) in the circuit should be observed before cranking the engine.