CM2150 Electronic Control System – FAULT CODE 1993

  Printable Version

Overview

ISB, ISC, and ISL – Aftertreatment Differential Pressure Sensor SMALL | MEDIUM | LARGE

Circuit Description

The engine aftertreatment system monitors for the presence of the aftertreatment particulate trap. This diagnostic checks to make sure that the aftertreatment particulate trap is present and functioning correctly.

Component Location

The aftertreatment particulate trap is located in the exhaust system and is installed by the original equipment manufacturer (OEM). Refer to the OEM troubleshooting and repair manual.

Conditions for Running the Diagnostics

This diagnostic runs when the engine is running and exhaust flow is above a minimum level.

Conditions for Setting the Fault Codes

This diagnostic monitors the aftertreatment diesel particulate trap differential pressure sensor. When the differential pressure is below a minimum value and exhaust flow rate is above a minimum flow rate, the fault code is set.

Action Taken When the Fault Code is Active

• The ECM will illuminate the amber CHECK ENGINE light immediately after the diagnostic runs and passes.
• Active regeneration of the aftertreatment diesel particulate filter will be disabled.
• The exhaust gas recirculation (EGR) valve operation will be disabled.

Conditions for Clearing the Fault Code

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

It will be necessary to run the engine at high idle to elevate the exhaust flow for this fault code to go inactive.

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.

Possible causes of this fault code include:

• The aftertreatment differential sensor can be stuck in range
• The aftertreatment diesel particulate filter has been removed from the vehicle
• The aftertreatment diesel particulate filter is cracked or broken
• The aftertreatment diesel particulate filter differential tubes are installed incorrectly, broken, loose, or have been tampered with
• The aftertreatment diesel particulate filter differential tubes are installed backwards.

Refer to Troubleshooting Fault Code t05-1993