Cummins X15 CM2350 X116B Performance Series (2018 & Newer) Fault Code: 4729 PID: SPN: 102 FMI: 1/1 Intake Manifold 1 Pressure – Data Valid But Below Normal Operating Range – Most Severe Level

Lamp:
Red

Reason:
Intake manifold pressure is below the minimum operating limit.

Effect:
Possible reduced engine performance.

Circuit Description:
The Engine Control Module (ECM) provides a 5 volt supply to the intake manifold pressure sensor on the sensor supply circuit. The ECM also provides a ground on the sensor return circuit. The intake manifold pressure sensor provides a signal to the ECM on the intake manifold pressure sensor signal circuit. This sensor signal voltage changes based on the pressure in the intake manifold.

Component Location:
The intake manifold 1 pressure/temperature sensor is located in the air intake manifold.

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

Conditions for Setting the Fault Code:
The Engine Control Module (ECM) detected the intake manifold pressure reading was below the expected level for the engine operating conditions.

Action Taken When the Fault Code is Active:
1. The ECM illuminates the red stop 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 using a diagnostic road test, utilize a route that incorporates both stop and go city type driving and steady state highway type driving. It may be necessary to load the unit for certain diagnostics in the ECM to run.
2. To validate the repair using a chassis dynamometer, utilize a routine that incorporates acceleration and motoring events, steady state highway type operation, and load. This will simulate normal driving and allow the diagnostics in the ECM to run.
3. The fault code status displayed by the recommended diagnostic tool or equivalent will change to inactive immediately after the diagnostic runs and passes.
4. The ECM will turn off the amber check engine lamp immediately after 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:
1. The intake manifold 1 pressure sensor monitors pressure in the intake manifold. This fault is set active when the intake manifold pressure is too low for the present engine operating conditions.
2. Possible causes of this fault are:
A. Leaks in the air intake system between the turbocharger and intake manifold.
B. A damaged intake manifold pressure sensor.
C. Restriction in the charge-air cooler.
D. Leaks in the EGR system plumbing.