CM850 Electronic Control System – FAULT CODE 2352

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Overview

EGR Valve Control Circuit SMALL | MEDIUM | LARGE

Circuit Description

The electronic control module (ECM) controls the EGR valve, opening and closing it based on various operating conditions. The EGR valve is opened and closed by a DC-motor that receives voltage from the ECM on the EGR valve motor signal (+) and (-) circuits. To open the valve, the motor receives voltage on the EGR valve motor signal (+) circuit. To close the valve, the motor receives voltage on the EGR valve motor signal (-) circuit.

Component Location

The EGR valve motor is located on the exhaust side of the engine and is attached to the EGR valve assembly, which is mounted to the exhaust manifold. Refer to Procedure 100-002 for a detailed component location view.

Shop Talk

The ECM monitors the voltage level of the circuit and logs a fault code if the voltage level indicates a short to ground. This fault is always set inactive when the keyswitch is turned ON. If there is a failure of this circuit, the fault code will not be set active until the valve has been actuated. For these reasons this troubleshooting tree must be used for both active and inactive fault codes. This also means that the only sufficient way for making sure that the repair is effective is to run the INSITE™ electronic service tool EGR Valve Test. Running the engine may not be enough to verify that the fix was effective.

Possible causes of this fault are that the EGR motor (+ or – ) leads could be shorted to a voltage source in the harness or ECM.

Refer to Troubleshooting Fault Code t05-2352