EGR Valve Control Circuit – Mechanical System Not Responding or Out of Adjustment
Overview
| CODE | REASON | EFFECT |
| Fault Code: 2357 PID: S146 SPN: 2791 FMI: 7/7 LAMP: Amber SRT: |
The EGR valve motor has exceeded the duty cycle limit, indicating a stuck open EGR valve.
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Possible reduced engine performance.
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EGR Valve Position Circuit
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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 EGR valve was commanded open and the EGR valve was unable to move to the commanded position.
Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE lamp immediately when the diagnostic runs and fails.
- The EGR valve controller will wait for 5 seconds after each failed attempt and then try to open the valve again.
Active and stationary regeneration of the diesel particulate filter will be disabled.
Engine torque will be severely reduced if the engine is operated for an extended period of time with this fault active.
Conditions for Clearing the Fault Code
- 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.
- 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.
- The fault code status displayed by the recommended Cummins electronic service tool or equivalent 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.
- The “Reset All Faults” command in the recommended Cummins electronic service tool or equivalent can be used to clear active and inactive faults.
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.
Troubleshooting Summary
Verification
Conditions
- Turn keyswitch ON.
- Connect the recommended Cummins electronic service tool or equivalent.
Action
- Use the recommended Cummins electronic service tool or equivalent to read the fault codes.
Specification
Before troubleshooting this fault code, troubleshoot any fault code that is active or has more than one inactive count within the last 25 engine operating hours from the following list:
- EGR: 1896, 2272
Linked Solutions
- None
Repair
- Perform a search on the appropriate fault codes.
Validation
- None
Verification
Conditions
- Connect all components.
Action
- Turn keyswitch ON.
- Connect the recommended Cummins electronic service tool or equivalent.
- Wait for 90 seconds.
- Turn keyswitch OFF.
- Wait for 30 seconds.
- Turn keyswitch ON.
- Use the recommended Cummins electronic service tool or equivalent to read the fault codes.
Specification
- A malfunctioning EGR valve has been detected if a fault code from the following list is active or has more than one inactive count within the last 25 engine operating hours: 2357
Linked Solutions
- None
Repair
- Clean or replace the EGR valve.
Validation
- Connect all components
- Connect the recommended Cummins electronic service tool or equivalent.
- Disable the fault code.
- Operate the engine within the “Conditions for Clearing the Fault Code” found in the Overview section of the troubleshooting procedure.
- Verify that the fault code is no longer active.
- Check ECM Calibration Revision History
- Use the recommended Cummins electronic service tool or equivalent to find the current ECM code and revision number in the ECM.
- Compare the ECM code and revision number in the ECM to the calibration revisions listed in the ECM Calibration Revision History Database for applicable changes related to this fault code.
- Refer to ECM Calibration Revision History Database.
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the engine wiring harness connector from the ECM.
- Disconnect the EGR valve from the engine wiring harness.
Action
- Inspect the pins and connectors for damage.
- Measure the resistance between the EGR valve motor A SIGNAL pin at the EGR valve engine wiring harness connector and the EGR valve motor A SIGNAL pin at the engine wiring harness ECM connector.
- Measure the resistance between the EGR valve motor B SIGNAL pin at the EGR valve engine wiring harness connector and the EGR valve motor B SIGNAL pin at the engine wiring harness ECM connector.
- Measure the resistance between the EGR valve motor C SIGNAL pin at the EGR valve engine wiring harness connector and the EGR valve motor C SIGNAL pin at the engine wiring harness ECM connector.
- Measure the resistance between the EGR valve motor RETURN pin at the EGR valve engine wiring harness connector and the EGR valve motor RETURN pin at the engine wiring harness ECM connector.
- Refer to the circuit diagram or wiring diagram for connector pin identification.
Specification
- A malfunctioning engine wiring harness has been detected if the resistance is greater than the following specification: 10 Ω
Linked Solutions
- None
Repair
- Repair or replace the engine wiring harness.
Validation
- Connect all components
- Connect the recommended Cummins electronic service tool or equivalent.
- Disable the fault code.
- Operate the engine within the “Conditions for Clearing the Fault Code” found in the Overview section of the troubleshooting procedure.
- Verify that the fault code is no longer active.
- Check ECM Calibration Revision History
- Use the recommended Cummins electronic service tool or equivalent to find the current ECM code and revision number in the ECM.
- Compare the ECM code and revision number in the ECM to the calibration revisions listed in the ECM Calibration Revision History Database for applicable changes related to this fault code.
- Refer to ECM Calibration Revision History Database.
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the EGR valve motor from the engine wiring harness.
- Disconnect the engine wiring harness connector from the ECM.
Action
- Inspect the pins and connectors for damage.
- Measure the resistance between the EGR valve position SIGNAL A pin at the engine wiring harness ECM connector and ground.
- Measure the resistance between the EGR valve position SIGNAL B pin at the engine wiring harness ECM connector and ground.
- Measure the resistance between the EGR valve position SIGNAL C pin at the engine wiring harness ECM connector and ground.
- Refer to the circuit diagram or wiring diagram for connector pin identification.
Specification
- A malfunctioning engine wiring harness has been detected if the resistance is less than the following specification: 100k Ω
Linked Solutions
- None
Repair
- Repair or replace the engine wiring harness.
Validation
- Connect all components
- Connect the recommended Cummins electronic service tool or equivalent.
- Disable the fault code.
- Operate the engine within the “Conditions for Clearing the Fault Code” found in the Overview section of the troubleshooting procedure.
- Verify that the fault code is no longer active.
- Check ECM Calibration Revision History
- Use the recommended Cummins electronic service tool or equivalent to find the current ECM code and revision number in the ECM.
- Compare the ECM code and revision number in the ECM to the calibration revisions listed in the ECM Calibration Revision History Database for applicable changes related to this fault code.
- Refer to ECM Calibration Revision History Database.
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the engine wiring harness connector from the ECM.
- Disconnect the EGR valve motor from the engine wiring harness.
Action
- Inspect the pins and connectors for damage.
- Measure the resistance between the EGR valve motor SIGNAL A pin at the engine wiring harness ECM connector and ground.
- Measure the resistance between the EGR valve motor SIGNAL B pin at the engine wiring harness ECM connector and ground.
- Measure the resistance between the EGR valve motor SIGNAL C pin at the engine wiring harness ECM connector and ground.
- Refer to the circuit diagram or wiring diagram for connector pin identification.
Specification
- A malfunctioning engine wiring harness has been detected if the resistance is less than the following specification: 100k Ω
Linked Solutions
- None
Repair
- Repair or replace the engine wiring harness.
Validation
- Connect all components
- Connect the recommended Cummins electronic service tool or equivalent.
- Disable the fault code.
- Operate the engine within the “Conditions for Clearing the Fault Code” found in the Overview section of the troubleshooting procedure.
- Verify that the fault code is no longer active.
- Check ECM Calibration Revision History
- Use the recommended Cummins electronic service tool or equivalent to find the current ECM code and revision number in the ECM.
- Compare the ECM code and revision number in the ECM to the calibration revisions listed in the ECM Calibration Revision History Database for applicable changes related to this fault code.
- Refer to ECM Calibration Revision History Database.
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the engine wiring harness connector from the ECM.
- Disconnect the EGR valve from the engine wiring harness.
Action
- Inspect the pins and connectors for damage.
- Measure the resistance between the EGR valve position SIGNAL A pin at the engine wiring harness ECM connector and all other pins in the ECM connector.
- Measure the resistance between the EGR valve position SIGNAL B pin at the engine wiring harness ECM connector and all other pins in the ECM connector.
- Measure the resistance between the EGR valve position SIGNAL C pin at the engine wiring harness ECM connector and all other pins in the ECM connector.
- Refer to the circuit diagram or wiring diagram for connector pin identification.
Specification
- A malfunctioning engine wiring harness has been detected if the resistance is less than the following specification: 100k Ω
Linked Solutions
- None
Repair
- Repair or replace the engine wiring harness.
Validation
- Connect all components
- Connect the recommended Cummins electronic service tool or equivalent.
- Disable the fault code.
- Operate the engine within the “Conditions for Clearing the Fault Code” found in the Overview section of the troubleshooting procedure.
- Verify that the fault code is no longer active.
- Check ECM Calibration Revision History
- Use the recommended Cummins electronic service tool or equivalent to find the current ECM code and revision number in the ECM.
- Compare the ECM code and revision number in the ECM to the calibration revisions listed in the ECM Calibration Revision History Database for applicable changes related to this fault code.
- Refer to ECM Calibration Revision History Database.
If all steps have been completed and no root cause has been identified, then follow the technical escalation process.