Cummins ISB4.5 CM2150 Fault Code: 2186 PID: SID 232 SPN: 3512 FMI: 4 Sensor Supply 4 Circuit – Voltage Below Normal or Shorted to Low Source.

Circuit Description
Sensor supply 4 of the engine control module (ECM) provides a 5 volt supply to the accelerator pedal position sensor. The accelerator position sensor is a Hall effect sensor attached to the accelerator pedal. The accelerator position sensor varies the signal voltage to the ECM as the accelerator pedal is depressed and released. Low signal voltage is received by the ECM when the accelerator pedal is at 0 percent. A high signal voltage is received by the ECM when the accelerator pedal is at 100 percent. The accelerator pedal position circuit contains an accelerator pedal position 5 volt supply, accelerator pedal position return, and accelerator pedal position signal.

Component Location
The accelerator pedal is located in the cab. Refer to the original equipment manufacturer (OEM) troubleshooting and repair manual.

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

Conditions for Setting the Fault Codes
The ECM detects that the sensor supply 4 signal voltage is less than 4.75-VDC for more than 1 second.

Action Taken When the Fault Code is Active
-The ECM illuminates the amber CHECK ENGINE light and/or the malfunction indicator lamp (MIL) immediately when the diagnostic runs and fails.
-The engine will only die

Conditions for Clearing the Fault Code
-To validate the repair, start the engine and let it idle for 1 minute.
-The ECM will turn off the amber CHECK ENGINE light 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 the MIL can also be cleared with INSITE™ electronic service tool.

Shop Talk
Low voltage on the 5 volt supply wire can be caused by a short circuit to ground in the supply wire, a short circuit between the supply wire and return circuit, a malfunctioning accelerator, or a malfunctioning ECM power supply.