Engine Oil Pressure Sensor/Switch Diagnosis

Schematic:

CIRCUIT DESCRIPTION

The engine oil pressure sensor is a solid state transducer. The engine oil pressure sensor sends oil pressure information to the PCM. The PCM transmits the oil pressure information to the Instrument Panel Cluster (IPC) via the serial data CKT 1807.

The engine oil pressure is displayed on the scan tool in volts. A low voltage reading indicates a low oil pressure. As the oil pressure increases, the voltage level also increases. The normal range of the sensor signal voltage is 0.5 volts at 0 kPa (0 psi) to 4.5 volts at 883 kPa (128 psi).


DIAGNOSTIC AIDS
For diagnosis of the instrument panel, refer to A Diagnostic System Check - Instrument Cluster in Instrument Panel, Gauges and Console. Testing and Inspection
Check for the following conditions:
^ A faulty connection at the PCM or the engine oil pressure sensor, Inspect harness connectors for the following conditions:
- Backed out terminals
- Improper mating
- Broken locks
- Improperly formed or damaged terminals, use a corresponding mating terminal to test for proper terminal tension.
- Faulty terminal to wire connections
^ Inspect the wiring harness for damage.
^ The engine oil pressure sensor diagnostic table is intended to isolate electrical faults that affect the engine oil pressure sensor, the PCM, and related circuits. If a problem with engine oil pressure can not be isolated using the diagnostic table, refer to A Diagnostic System Check - Instrument Cluster in Instrument Panel, Gauges and Console. Testing and Inspection


TEST DESCRIPTION

Steps 1 - 11:

Steps 12 - 16:

The numbers below refer to the step numbers on the diagnostic table.
3. Tests for the proper operation of the circuit in the low voltage range.
4. Tests for the proper operation of the circuit in the high voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to ground.
5. Tests for a short to voltage in the 5 volt reference circuit.
6. Tests for a high resistance or an open in the ground circuit.
15. This vehicle is equipped with a PCM which utilizes an electrically Erasable Programmable Read-only Memory (EEPROM). If the PCM is replaced, the new PCM must be programmed.