Cummins X15 CM2350 X116B Performance Series (2018 & Newer) Fault Code: 7234 PID: SPN: 188 FMI: 1/17 Engine Speed At Idle – Data Valid But Below Normal Operating Range – Least Severe Level

Lamp:
Amber

Reason:
Engine is not maintaining the governed idle speed.

Effect:
None on performance.

Circuit Description:
The Engine Control Module (ECM) continuously monitors the engine speed at idle and adjusts fueling to maintain governed idle speed.

Component Location:
The engine speed is monitored by the crankshaft and/or camshaft position sensors.

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the engine is operating at idle and PTO is not active.

Conditions for Setting the Fault Code:
The Engine Control Module (ECM) detected the engine speed was 50 rpm below governed idle speed for 30 seconds.

Action Taken When the Fault Code is Active:
The ECM illuminates the amber check engine lamp and/or Malfunction Indicator Lamp (MIL) after the diagnostic fails on two consecutive trips.

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:
Possible causes of this fault code include:
1. Fuel system malfunction.
2. Crankshaft position sensor malfunction.
3. Camshaft position sensor malfunction.
4. Increased engine accessory load.