Cummins ISL CM850 (2003-06) Fault Code: 238 PID: SID 232 SPN: 611 FMI: 4 Sensor Supply 3 Circuit – Voltage Below Normal, or Shorted to Low Source. Low voltage detected on the +5 volt sensor supply circuit to the engine speed sensor.

Cummins ISL CM850 (2003-06) Fault Code: 238 PID: SID 232 SPN: 611 FMI: 4 Sensor Supply 3 Circuit – Voltage Below Normal, or Shorted to Low Source. Low voltage detected on the +5 volt sensor supply circuit to the engine speed sensor.

Low voltage on the +5 VDC supply line can be caused by a short circuit to ground in a supply line, a short circuit between a supply line or a return line, a failed sensor, or a failed ECM power supply.

Possible repairs:

1)Replace the engine speed sensor.