Cummins ISB4.5 CM2150 Fault Code: 177 PID: SID 254 SPN: 3464 FMI: 7 Electronic Throttle Control Actuator – Mechanical System Not Responding or Out of Adjustment.

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 actuator motor signal (-) circuit.

Component Location
The engine intake throttle actuator is mounted in the intake air stream, between the charge-air cooler and 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
-This fault code is set when the duty cycle required to open the intake throttle actuator is greater than 95 percent for 3 seconds.

-The fault code will be inactive at key ON. It will only go active if the engine intake throttle actuator is commanded open and the engine intake throttle actuator is unable to move to the commanded position.

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 engine intake throttle actuator operation will be disabled.

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 the INSITE™ electronic service tool.

Shop Talk
The ECM monitors the duty cycle of the actuator and logs a fault code if the duty cycle is too high. This fault is always set inactive when the keyswitch is turned ON. If there is a malfunction, 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
-Malfunctioning intake throttle actuator position sensor; mechanical or electrical malfunction.
-Intake throttle actuator assembly failure requiring a high current to operate the actuator, such as a stuck or sticking valve.

NOTE: Do not supply 12-VDC to the engine 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 sensor is rated at 5-VDC, and sensor damage may occur.