PACCAR PX-9 CM2350 (2013-17) Fault Code:2357 PID:SID 146 SPN:2791 FMI:7 EGR Valve Control Circuit – Mechanical System Not Responding or Out of Adjustment

Reason:
EGR Valve Control Circuit – Mechanical System Not Responding or Out of Adjustment. The EGR valve motor has exceeded the duty cycle limit, indicating a stuck open EGR valve.

Effect:
EGR valve actuation will be disabled.

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.

Component Location:
The EGR valve location can vary, depending on engine application.

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

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected the duty cycle required to open the EGR valve was greater than 95 percent for 3 seconds. The fault code is triggered after two failed attempts. The fault code will be inactive at key ON. It will only go active if the EGR valved is commanded open and the EGR valve is unable to move to the commanded position.

Action Taken When the Fault Code is Active:
1) The ECM illuminates the amber CHECK ENGINE lamp immediately when the diagnostic runs and fails.
2) Active and stationary regeneration of the diesel particulate filter will be disabled.
3) Exhaust Gas Recirculation (EGR) valve operation will be disabled.
4) 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 1 minute.
2) The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
3) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
4) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults.

Shop Talk:
This fault code is triggered when the EGR valve motor is unable to move the EGR valve in the open position. This is normally caused by a restriction in the EGR valve not allowing the EGR valve to move to the commanded position. The aftertreatment system must be inspected after making the appropriate repair outlined in this fault code troubleshooting tree. Progressive damage to the aftertreatment system may have occurred. Perform the aftertreatment initial check procedure to test for a damaged diesel particulate filter.

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