Cummins ISB4.5 CM2150 Fault Code: 3542 PID: SPN: 51 FMI: 2 Engine Intake Throttle Actuator Position Sensor – Data Erratic, Intermittent, or Incorrect.

Circuit Description
The engine control module (ECM) uses the engine intake throttle actuator position sensor to determine whether or not the actuator is meeting the commanded position. The ECM supplies 5 volts to the engine intake throttle actuator position signal circuit, and the engine intake throttle actuator position sensor outputs a voltage signal to the ECM based on the actuator position. The ECM converts this signal into a percentage value, 0 to 100, indicating actuator position. A fully open actuator is equivalent to 100 percent.

Component Location
The engine intake throttle actuator position sensor is internal to the intake throttle actuator assembly and can not be serviced separately.

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

Conditions for Setting the Fault Codes
The ECM detects that the engine intake throttle actuator position sensor is reporting an erratic value, or the intake throttle actuator position is not changing with engine operating conditions.

Action Taken When the Fault Code is Active
-The ECM illuminates the amber CHECK ENGINE lamp and/or the malfunction indicator lamp (MIL) immediately when the diagnostic runs and fails.
-Intake air throttle actuator operation will be disabled and the intake air throttle actuator will be opened.

Conditions for Clearing the Fault Code
-To validate the repair, perform a key cycle, and leave the key in the ON position for 1 minute. The intake throttle actuator will perform an auto-zero immediately after key-on.
-The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
-The ECM will turn off the MIL after three consecutive ignition cycles that the diagnostic runs and passes.
-This fault code and MIL can also be cleared with INSITE™ electronic service tool.

Possible Causes
-Frozen, plugged, or restricted engine intake air throttle
-Intermittent open or short in the wiring harness
-Malfunctioning intake throttle actuator position sensor
-Malfunctioning ECM
-Sticky or broken intake throttle actuator.

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.