Cummins ISB4.5 CM2150 Fault Code: 175 PID: SID 254 SPN: 3464 FMI: 3 Electronic Throttle Control Actuator Driver Circuit – Voltage Above Normal or Shorted to High Source.

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

Component Location
The intake throttle actuator is mounted in the intake air stream, between the charge-air cooler and the intake manifold.

Conditions for Running the Diagnostics
This diagnostic runs continuously when the keyswitch is in the ON position and the engine is operating.

Conditions for Setting the Fault Codes
The ECM detects a short circuit to voltage or open circuit in the intake throttle motor supply circuit.

Action Taken When the Fault Code is Active
The ECM illuminates the red STOP ENGINE lamp and/or the malfunction indicator lamp (MIL) immediately when the diagnostic runs and fails. The intake throttle actuator operation will be disabled, and the actuator will default to the open position.

Conditions for Clearing the Fault Code
-The fault code will always be inactive at key ON. To validate the repair, start and idle the engine for 1 minute. If the fault code does not become active again, the repair has been validated.
-The ECM will turn off the MIL after 3 consecutive ignition cycles that the diagnostic runs and passes.
-This fault code can also be cleared with INSITE™ electronic service tool.

Shop Talk
The ECM monitors the voltage level of the circuit and logs a fault code if the voltage level indicates a short to voltage. 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 actuator has been actuated. For these reasons, this troubleshooting tree must be used for both active and inactive fault codes.

Possible causes of this fault are that the intake throttle actuator motor (+ or – ) wires can become open or shorted to a voltage source in the harness or ECM.

NOTE: Do not supply 12V to the intake throttle actuator position sensor, or short the intake throttle actuator motor wires to the intake throttle actuator position sensor. The intake throttle actuator position is rated at 5V, and sensor damage can occur.