CM871 and CM876 Electronic Control Systems, ISX and ISM Engines – FAULT CODE 2357

  Printable Version

Overview

ISX – EGR Valve Circuit SMALL | MEDIUM | LARGE

ISM – EGR Valve Circuit SMALL | MEDIUM | LARGE

Circuit Description

The exhaust gas recirculation (EGR) valve is a smart device that receives commands from the engine electronic control module (ECM) via the J1939 data link. The EGR valve performs its own internal diagnostics and reports failures back to the primary engine ECM using the J1939 data link.

The EGR valve is opened by a motor located on top of the EGR valve. A motor shaft extends from the motor and contacts the dual-poppet valve to open the EGR valve. The EGR valve motor does not actually retract the EGR valve. The motor current is reduced and the spring pushes the EGR valve closed.

Component Location

The EGR valve location can vary depending on the engine application. Refer to Procedure 100-002 (Engine Diagrams) in Section E for a detailed component location view.

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

This fault code is set when the duty cycle required to open the EGR valve is greater than 95 percent for 3 seconds. The EGR valve controller will try to open the EGR valve again after 10 seconds. The fault code is triggered after three failed attempts.

Action Taken When the Fault Code is Active

• The ECM illuminates the amber CHECK ENGINE light immediately when the diagnostic runs and fails.
• The EGR valve will stop responding to commands and the spring will close the EGR valve.

Conditions for Clearing the Fault Code

The ECM will turn off the amber CHECK ENGINE light and clear the fault code after the keyswitch is cycled and the diagnostic runs and passes. The fault code will be inactive at key-on. It will only go active if the EGR valve is commanded open and the EGR valve is unable to move to the commanded position.

Shop Talk

Verify the electronic control module (ECM) calibration is correct. Check the calibration revision history found on Quickserve™ Online for applicable fixes to the calibration stored in the ECM. If necessary, recalibrate the ECM. Refer to Procedure 019-032 (ECM Calibration Code) in Section 19 in the corresponding Troubleshooting and Repair Manual for the engine being serviced.

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 fault code will be inactive at key-on. It will only go active if the EGR valve is commanded open and the EGR valve is unable to move to the commanded position.

The ECM calibration contains an automatic EGR valve override test. Thirty seconds after turning the keyswitch on, the EGR valve all be commanded open to 60 percent and will be held in this position for 1 minute and then it will be commanded to 0 percent open. Turn the keyswitch off for 20 seconds and then turn the keyswitch on and read the fault codes. If Fault Code 1896 is active, this indicates that the EGR valve is stuck in the open 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 Snap Acceleration Test to check for a damaged diesel particulate filter.

• Refer to Procedure 014-013 (Aftertreatment Testing) in Section 14 in the ISM, ISMe, and QSM11 Service Manual, Bulletin 3666322, or the Signature™, ISX and QSX15 Service Manual, Bulletin 3666239, for reuse guidelines.

Refer to Troubleshooting Fault Code t05-2357