PACCAR PX-9 CM2350 (2013-17) Fault Code:3138 PID: SPN:5019 FMI:2 Engine Exhaust Gas Recirculation Outlet Pressure – Data Erratic, Intermittent, or Incorrect

Reason:
Engine Exhaust Gas Recirculation Outlet Pressure – Data Erratic, Intermittent or Incorrect. The EGR orifice pressure sensor is reading an erratic value at initial key ON or while the engine is running.

Effect:
Possible reduced engine performance

Circuit Description:
The engine control module (ECM) provides a 5 volt supply to the EGR orifice pressure sensor on the sensor supply circuit. The ECM also provides a ground on the sensor return circuit. The EGR orifice pressure sensor provides a signal to the ECM on the EGR orifice pressure sensor signal circuit. This sensor signal voltage changes based on the pressure at the EGR orifice pressure sensor.

Component Location:
The EGR orifice pressure sensor is mounted on the EGR mass measurement assembly near the EGR differential pressure sensor.

Conditions for Running the Diagnostics:
This is a two part diagnostic.
1) One part runs immediately after the keyswitch is turned OFF, and the engine coolant temperature is above 70°C or 158°F.
2) The second part runs continuously while the engine is running

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected the EGR orifice pressure sensor was not changing with engine conditions or was incorrect at key OFF.

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, start the engine and let it idle for 5 minutes. After 5 minutes, shut OFF the engine, perform a key cycle, and leave the key in the ON position for 1 minute.
2) The fault code status displayed by INSITE™ electronic service tool 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 INSITE™ electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.

Shop Talk:
N/A

Possible Causes:
1) A damaged EGR orifice pressure sensor
2) High resistance in the wiring harness on the signal or return wire
3) Plugged or restricted EGR differential pressure sensor flow ports