P0298

P0298-ENGINE OIL TEMPERATURE TOO HIGH





For a complete wiring diagram, refer to the Wiring Information.

Theory of operation

The Engine Oil Temperature (EOT) Sensor is a variable resistor that measures the temperature of the engine oil. The Powertrain Control Module (PCM) supplies a 5-Volt reference and a ground to the sensors low reference signal circuit. When the oil temperature is low, the sensor resistance is high. When the oil temperature is high, the sensor resistance is low.

- When Monitored:
The engine oil temperature has dropped below a calibrated value. Engine start up.

- Set Condition:
The Engine oil temperature rises faster than a calibrated modeled temperature. When the actual oil temperature exceeds the high boundary of the calibrated modeled temperature for three minutes the fault is set. Two trip fault. Three good trips to turn off the MIL.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. DTC IS ACTIVE

NOTE: Diagnose any other Oil Temperature sensor or system voltage DTCs before continuing.

1. Turn the ignition off.
2. If possible, allow the vehicle to sit with the ignition off for more than 60 minutes in an environment where the temperature will allow the oil temperature to cool down.
3. Start the engine and allow it to reach normal operating conditions.
4. With the scan tool, select View DTCs.

Is the status Active or Pending for this DTC?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test

2. ENGINE OIL/ENGINE MECHANICAL

NOTE: The following items should be considered before determining the cause of this DTC. Failure to do so may lead to misdiagnosis.
- ENGINE MECHANICAL TOLERANCES OUT OF SPECIFICATION
- ENGINE OIL PRESSURE OUT OF SPECIFICATION
- LOW ENGINE OIL
- DETERIORATED OR DIRTY OIL
- ENGINE OIL CONTAMINATED (i.e., coolant and/or fuel)

If any of the above conditions are found, repair as necessary.

Were any of the above conditions present?

Yes

- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Go To 3

3. ENGINE OIL TEMPERATURE SENSOR VOLTAGE
1. Turn the ignition off.
2. Disconnect the Engine Oil Temperature Sensor harness connector.
3. Turn the ignition on.
4. With the scan tool, read the Engine Oil Temperature Sensor voltage.

NOTE: The sensor voltage should be approximately 5.0 Volts (plus or minus.1 Volt) with the connector disconnected.

Does the scan tool display the voltage as described above?

Yes

- Go To 4

No

- Go To 5

4. ENGINE OIL TEMPERATURE SENSOR




1. Turn the ignition off.
2. Connect a jumper wire between the (G24) EOT Signal circuit and the (K915) Sensor Ground circuit in the Engine Oil Temperature Sensor harness connector.
3. Turn the ignition on.
4. With the scan tool, read the Engine Oil Temperature Sensor voltage.

NOTE: The sensor voltage should be approximately 0.0 Volts (plus or minus.1 Volt) with the jumper wire in place.

Does the scan tool display the voltage as described above?

Yes

- Verify that there is good pin to terminal contact in the EOT Sensor and Control Module connectors. Replace the Engine Oil Temperature Sensor if no problems were found with the connectors. Oil Temperature Sensor - Removal
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Go To 5

5. (G24) EOT SIGNAL CIRCUIT HIGH RESISTANCE




1. Turn the ignition off.
2. Measure the resistance of the (G24) Engine Oil Temp Signal circuit from the Engine Oil Temp Sensor harness connector to the PCM C2 harness connector.
3. Start the engine.

Is the resistance below 5.0 Ohms?

Yes

- Go To 6

No

- Repair the open or excessive resistance in the (G24) Engine Oil Temp Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

6. (K915) SENSOR GROUND CIRCUIT HIGH RESISTANCE




1. Measure the resistance of the (K915) Sensor ground circuit from the Engine Oil Temp Sensor harness connector to the PCM C2 harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 7

No

- Repair the (K915) Sensor Ground circuit for high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

7. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Engine Oil Temperature Sensor and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
5. Look for the data to change or for the DTC to reset during the wiggle test.
6. Perform any Technical Service Bulletins that may apply.

Were any problems found?

Yes

- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Replace the Powertrain Control Module (PCM). Powertrain Control Module - Removal.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.