P0197

DTC P0197 or P0198

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.



DTC Descriptors
DTC P0197
- Engine Oil Temperature (EOT) Sensor Circuit Low Voltage

DTC P0198
- Engine Oil Temperature (EOT) Sensor Circuit High Voltage




Diagnostic Fault Information






Typical Scan Tool Data






Circuit/System Description

The engine oil temperature (EOT) sensor is a variable resistor that measures the temperature of the engine oil. The engine control module (ECM) supplies 5 volts on the EOT signal circuit, and a ground to the low reference circuit.


Monitoring the engine oil temperature is necessary for optimal control of the cam phasers. The oil temperature is monitored from dual function oil level switch and temperature sensor located in the oil pan.


Conditions for Running the DTC


P0197
* The engine run time is greater than 20 seconds.
OR
* The ECT sensor is less than 150°C (302°F).
* The DTC runs continuously when the above enable conditions are met.



P0198
* The engine run time is greater than 20 seconds.
OR
* The ECT sensor is greater than -40°C (-40°F).
* The DTC runs continuously when the above enable conditions are met.



Conditions for Setting the DTC

P0197

The EOT sensor is greater than 162°C (324°F) for greater than 25 seconds.

P0198

The EOT sensor is less than -60°C (-76°F) for greater than 25 seconds.


Action Taken When the DTC Sets

DTCs P0197 and P0198 are Type B DTCs.


Conditions for Clearing the MIL/DTC

DTCs P0197 and P0198 are Type B DTCs.


Reference Information
Schematic Reference

* Engine Controls Schematics (Electrical Diagrams)
* Instrument Cluster Schematics (Instrument Cluster Schematics)

Connector End View Reference

Component Connector End Views (Connector Views)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

DTC Type Definitions

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information


Circuit/System Verification

Important: Perform this verification procedure only if the ignition has been OFF for 10 hours or more.



1. Ignition ON, observe the scan tool IAT Sensor, Engine Oil temperature Sensor, and ECT Sensor parameters. The readings should be within 15°C (27°F) of each other and also the ambient temperature.
2. Operate the vehicle within the Conditions for Running the DTC to verify that the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.



Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the EOT sensor.
2. Ignition OFF for 90 seconds, test for less than 5 ohms of resistance between the low reference circuit terminal C and ground.

• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

3. Ignition ON, verify the scan tool Engine Oil temperature Sensor parameter is colder than -39°C (-38°F).

• If greater than the specified range, test the signal circuit terminal B for a short to ground. If the circuit tests normal, replace the ECM.


Important: If the 3A fuse in the jumper wire opens, the signal circuit is shorted to a voltage and the sensor may be damaged.


4. Install a 3A fused jumper wire between the signal circuit terminal B and the low reference circuit terminal C. Verify the scan tool EOT Sensor parameter is warmer than 149°C (300°F).

• If less than the specified range, test the signal circuit for a short to voltage or an open/high resistance, if the circuit tests normal, replace the ECM.

5. Ignition OFF, disconnect the harness connectors at the ECM.
6. Test for infinite resistance between the oil temperature sensor signal circuit terminal B and the oil level switch signal circuit terminal A.

• If less than the specified range, repair the short circuit between the oil temperature sensor signal circuit and the oil level switch signal circuit.

7. If all circuits test normal, replace the engine oil level sensor and/or switch assembly.



Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Engine Oil Level Sensor and/or Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for ECM replacement, setup, and programming