Cummins X12 CM2350 X119B (2018 & Newer) Fault Code: 4728 PID: SPN: 1209 FMI: 18 Exhaust Gas Pressure- Data Valid But Below Normal Operating Range- Moderately Severe Level

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.

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.

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

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 Diagnostics
This diagnostic runs when the engine is operating in SCR warm-up mode.

Conditions for Setting the Fault Codes
The Engine Control Module (ECM) detected both the VGT position and the difference of the exhaust pressure and intake manifold pressure are lower than commanded.

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
To validate the repair, start the engine and let it idle for up to 5 minutes.
The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
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.
The Reset All Faults command in INSITE™ electronic service tool 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:

A malfunctioning intake manifold pressure sensor
A malfunctioning exhaust gas pressure sensor
A malfunctioning turbocharger

Possible Cause:
1) Charge-air cooler failure
2) ECM calibration