13A-ENGINE OIL PRESSURE SWITCH SYSTEM

Inspection procedure 26: Engine oil pressure switch system

CIRCUIT OPERATION

Battery voltage is applied to the oil pressure switch from the ECM terminal OPSW.

COMMENT

Detect the engine oil pressure conditions and enter the result into the ECM. After starting the engine if the oil pressure rises to higher than the given pressure, the engine oil pressure switch turns OFF. Under this condition the ECM sends the command of turning off the oil warning lamp to the combination meter via CAN.

TROUBLESHOOTING HINTS (The most likely causes for this case: )

Engine oil pressure switch failed.
Open or shorted engine oil pressure switch circuit, harness damage, or connector damage.
ECM failed.

DIAGNOSIS

STEP 1. Measure the power supply voltage at engine oil pressure switch connector.

(1) Disconnect the engine oil pressure switch connector measure at the harness side.

(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal OPSW line and ground.

The voltage should equal battery positive voltage.

(4) Turn the ignition switch to the "LOCK" (OFF) position.

Is battery positive voltage (approximately 12 volts) present?

Go to Step 4.

Go to Step 2.

STEP 2. Check of short to ground and open circuit in OPSW line between ECM connector and engine oil pressure switch connector.

Is the harness wire in good condition?

Go to Step 3

Repair the connector(s) or wiring harness. Then confirm that the malfunction symptom is eliminated.

STEP 3. Using scan tool (M.U.T.-IIISE), check data list item 90: Engine Oil Pressure Switch.

caution

To prevent damage to scan tool (M.U.T.-IIISE), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-IIISE).

(1) Connect scan tool (M.U.T.-IIISE). Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-IIISE)

(2) Turn the ignition switch to the "ON" position.

(3) Set scan tool (M.U.T.-IIISE) to the data reading mode for item 90, Engine Oil Pressure Switch.

When the engine is stopped, "ON" should be displayed.
When the engine is idling, "OFF" should be displayed.

(4) Turn the ignition switch to the "LOCK" (OFF) position.

Is the operating properly?

It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/ Inspection Service Points - How to Cope with Intermittent Malfunctions

Replace the ECM (Refer to Removal and Installation

). Then confirm that the malfunction symptom is eliminated.

STEP 4. Check of harness damage in OPSW line between ECM connector and engine oil pressure switch connector.

Is the harness wire in good condition?

Replace the engine oil pressure switch. Then confirm that the malfunction symptom is eliminated.

Repair it. Then confirm that the malfunction symptom is eliminated.