Cummins X12 CM2350 X119B (2018 & Newer) Fault Code: 7155 PID: SPN: 629 FMI: 4/4 Engine Control Module Circuit – Voltage Below Normal or Shorted to Low Source

Lamp:
Amber

Reason:
Low voltage to the EGR valve device driver has been detected.

Effect:
Possible reduced engine performance.

Circuit Description:
The EGR valve device driver in the ECM provides power to the EGR valve motor. The EGR valve motor is used to move the EGR valve to the correct position, as commanded by the ECM.

Component Location:
The EGR valve device driver is internal to the ECM and can not be serviced separately.

Conditions for Running the Diagnostic:
This diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected low power at the EGR valve device driver. The ECM was no longer able to control the EGR valve.

Action Taken When the Fault Code is Active:
1. The ECM illuminates the amber check engine lamp and/or the Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails.
2. Exhaust Gas Recirculation (EGR) valve operation will be disabled.
3. Engine torque will be reduced if the engine is operated for an extended period of time with this fault active.

Conditions for Clearing the Fault Code:
1. To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
2. The fault code status displayed by the recommended diagnostic tool or equivalent will change to inactive immediately after the diagnostic runs and passes.
3. The ECM will turn off the amber check engine lamp immediately after the diagnostic runs and passes.
4. For On-Board Diagnostics (OBD) engines, the ECM will extinguish the Malfunction Indicator Lamp (MIL) after three consecutive trips where the diagnostic runs and passes.
5. The “reset all faults” command in the recommended diagnostic tool or equivalent can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.

Shop Talk:
This fault code indicates an internal failure in the ECM.