CM870 and ISX Engines – FAULT CODE 212

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Overview

Engine Oil Temperature Sensor Circuit SMALL | MEDIUM | LARGE

Circuit Description

The engine oil temperature sensor is used by the electronic control module (ECM) to monitor the engine oil temperature. The ECM monitors the voltage on the signal pin and converts this to a temperature value. The engine oil temperature value is used by the ECM for the engine protection system and engine emissions control.

Component Location

The engine oil temperature sensor is located on the intake side of the engine near the EGR connection tube below the integrated fuel system module (IFSM). Refer to Procedure 100-002 for a detailed component location view.

Shop Talk

Beginning with ESN 14039654, the temperature sensor return circuit was separated from the pressure sensor return circuit. For ESNs prior to this and with engine wiring harness Part Number 3682854, see the Common Pressure/Temperature Sensor Return Circuit above. For this ESN and greater or for any other engine wiring harness part number, see the Separate Pressure/Temperature Sensor Return Circuit above.

The engine oil temperature sensor shares return wires in the engine harness with other sensors. An open return can cause multiple fault codes to be active. Before troubleshooting Fault Code 212, check for multiple fault codes.

Possible causes of this fault code include:

• Open return circuit in the harness, connectors, sensor, or ECM
• Open signal circuit or shorted to a voltage source.

Refer to Troubleshooting Fault Code t05-212