CM870 and ISX Engines – FAULT CODE 154

  Printable Version

Overview

Intake Manifold Air Temperature Sensor Circuit SMALL | MEDIUM | LARGE

Circuit Description

The intake manifold air temperature sensor monitors intake manifold air temperature and passes information to the electronic control module (ECM) through the engine harness. If the intake manifold air temperature becomes too high, it will cause a derate condition.

Component Location

The intake manifold air temperature sensor is located in the air intake connection. Refer to Section E 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, refer to the Common Pressure/Temperature Sensor Return Circuit above. For this ESN and greater or for any other engine wiring harness part number, refer to the Separate Pressure/Temperature Sensor Return Circuit above.

The intake manifold air temperature sensor shares return wires in the engine harness with other sensors. Opens and shorts in the engine harness can cause multiple fault codes to be active. Before troubleshooting Fault Code 154 check for multiple fault codes.

Possible causes of this fault code include:

• Signal circuit shorted to ground in the harness or ECM
• Signal circuit shorted to return or ground in the sensor.

Refer to Troubleshooting Fault Code t05-154