Cummins X12 CM2350 X119B (2018 & Newer) Fault Code: 2533 PID: SPN: 1323 FMI: 11/31 Engine Misfire Cylinder 1 – Condition Exists

Lamp:
Red

Reason:
Engine misfire has been detected in cylinder number 1.

Effect:
Possible reduced engine performance.

Circuit Description:
The exhaust gas pressure sensor is used to measure exhaust gas pressure in the exhaust manifold. This information is used by the Engine Control Module (ECM) to control emissions and Exhaust Gas Recirculation (EGR) valve operation. The ECM provides a 5 volt supply to the exhaust gas pressure sensor on the sensor supply circuit. The ECM also provides a ground on the sensor return circuit. The exhaust gas pressure sensor provides a signal to the ECM on the exhaust gas pressure sensor signal circuit. This sensor signal voltage changes, based on the pressure in the exhaust manifold. The Engine Control Module (ECM) uses the exhaust gas pressure sensor signal to compare pressure increases to combustion events. A missing pressure increase corresponds to a missing combustion event.

Component Location:
The exhaust gas pressure sensor is located above the front section of the exhaust manifold and is plumbed into the exhaust manifold.

Conditions for Running the Diagnostic:
This diagnostic runs continuously when the engine is running.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected a cylinder 1 misfire.

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, start the engine and let it idle for up to 5 minutes.
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:
Causes of cylinder misfire can include:
1. Valve lash out of specification (compare actual valve lash to reset limits).
2. Cylinder malfunction (check for high blowby when the engine is loaded).
3. Valve train malfunction or valve held open (listen for intake valve “chirping” noise in the intake).
4. Extra, missing, or damaged sealing washer under an injector.
5. Injector malfunctions (swap injectors to see if the problem follows the indicated injector).
6. A malfunctioning exhaust gas pressure sensor.