CM871 and CM876 Electronic Control Systems, ISX and ISM Engines – FAULT CODE 2387

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Overview

ISX – VGT Actuator Circuit SMALL | MEDIUM | LARGE

ISM – VGT Actuator Circuit SMALL | MEDIUM | LARGE

Circuit Description

The variable geometry turbocharger (VGT) is electronically activated by the VGT actuator. The VGT actuator is a smart device that receives information via the J1939 data link from the primary engine electronic control module (ECM). The VGT actuator performs its own diagnostics and reports errors back to the primary engine ECM using the J1939 data link.

Component Location

The VGT actuator is located on the turbocharger bearing housing. Use the following procedure for a detailed component location view.Refer to Procedure 100-002 in Section E.

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 will set when the actual VGT actuator position can not meet the commanded position for more than 10 seconds.

Action Taken When the Fault Code is Active

• The ECM illuminates the amber CHECK ENGINE light immediately when the diagnostic runs and fails.
• The VGT actuator continuously attempts to meet position even when the lamp is ON. Active and stationary aftertreatment regeneration are disabled.

Conditions for Clearing the Fault Code

The ECM will turn off the amber CHECK ENGINE light immediately after the diagnostic runs and passes.

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, calibrate the ECM. Use the following procedure in the corresponding Troubleshooting and Repair Manual for the engine being serviced. Refer to Procedure 019-032 in Section 19.

This fault code will set when the actual VGT actuator position can not meet the commanded position for more than 10 seconds.

Large boost pressure leaks can also cause this fault code.

• For ISM engines, use the following procedure in the ISM, ISMe, and QSM11 Service Manual, Bulletin 3666322.Refer to Procedure 010-024 in Section 10.
• For ISX engines, use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239.Refer to Procedure 010-024 in Section 10.

The aftertreatment system must be inspected after making the appropriate repair outlined in this fault code troubleshooting tree. Progressive damage to the aftertreatment system can have possibly occurred. Perform the Snap Acceleration Test to check for a damaged diesel particulate filter.

• For ISM engines, use the following procedure in the ISM, ISMe, and QSM11 Service Manual, Bulletin 3666322.Refer to Procedure 014-013) in Section 14. i
• For ISX engines, use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239.Refer to Procedure 014-013 in Section 14.

Inspect the aftertreatment system for potential damage.

Refer to Troubleshooting Fault Code t05-2387