PACCAR PX-9 CM2350 (2013-17) Fault Code:2272 PID:27 SPN:27 FMI:4 EGR Valve Position Circuit – Voltage Below Normal or Shorted to Low Source

Reason:
EGR Valve Position Circuit – Voltage Below Normal or Shorted to Low Source. Low signal voltage has been detected at the EGR valve position sensor circuit.

Effect:
Possible reduced engine performance

Circuit Description:
The exhaust gas recirculation (EGR) valve is controlled by a brushless motor located on top of the EGR valve. The EGR valve motor uses three different motor legs to move the valve through its range of motion. The ECM uses the EGR motor A, B, and C wires to command the EGR valve to the appropriate position in order to meet EGR flow targets.The EGR valve motor contains three position sensors that detect the location of the EGR valve. These sensors report the position of the valve back to the ECM over the EGR valve position A, B, and C wires.

The EGR valve motor contains three position sensors that detect the location of the EGR valve. These sensors report the position of the valve back to the ECM over the EGR valve position A, B, and C wires.

Component Location:
The EGR valve position sensor is internal to the EGR valve assembly and can not be serviced separately.

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected the EGR valve position sensor signal voltage was less than a calibratible value.

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, key OFF for 1 minute, then key ON 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:
EGR valve position sensor wiring shorted to ground, open circuit, or shorted to power supply.
1) Loss of the EGR valve position sensor supply voltage or the ground circuit.

Possible Causes:
1) Inactive fault codes
2) Faulty engine harness and EGR valve connector pins
3) Faulty ECM