CM871 and CM876 Electronic Control Systems, ISX and ISM Engines – FAULT CODE 2881

  Printable Version

Overview

ISX and ISM – Aftertreatment Fuel Injector System SMALL | MEDIUM | LARGE

Circuit Description

The aftertreatment fuel pressure sensor is used to monitor the fuel pressure into the aftertreatment system. The electronic control module (ECM) supplies the aftertreatment fuel pressure sensor a 5-volt reference voltage. When the fuel pressure is low, the sensor signal voltage is low. When the fuel pressure is high, the sensor signal voltage is near the 5-volt reference voltage. The ECM monitors the aftertreatment fuel pressure signal circuit voltage to calculate the pressure of the fuel within the aftertreatment system.

Component Location

The aftertreatment fuel pressure sensor is located in the aftertreatment fuel shutoff manifold. Refer to Procedure 100-002 in Section E.

Conditions for Running the Diagnostics

This diagnostic runs during the first 5 minutes of engine operation.

Conditions for Setting the Fault Codes

The aftertreatment fuel pressure sensor detects that the fuel pressure in the aftertreatment system is below the minimum fuel pressure required for fuel injection into the aftertreatment system.

Action Taken When the Fault Code is Active

• The ECM will set the fault code active immediately after the diagnostic runs and fails.

Conditions for Clearing the Fault Code

The ECM will set the fault code inactive following a key cycle or 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, recalibrate the ECM. Refer to Procedure 019-032 in Section 19.

Possible causes of this fault code include:

• Low fuel pressure detected in the aftertreatment fuel supply system.
• On ISM engines, check the fuel rifle connection at the cylinder head. Remove the aftertreatment fuel supply line and inspect the fuel rifle in the cylinder head for a plastic plug or ”stringer” that may be restricting the fuel flow to the aftertreatment system.
• 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. Remove the exhaust aftertreatment system from the vehicle and inspect for reuse. Refer to Procedure 014-013 in Section 14. This procedure is found in the Service Manual, ISM, ISMe, and QSM11, Bulletin 3666322, or the Service Manual, Signature, ISX, and QSX15, Bulletin 3666239.

Refer to Troubleshooting Fault Code t05-2881