CM2150 Electronic Control System – FAULT CODE 2638

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Overview

ISB, ISC, and ISL – Aftertreatment System SMALL | MEDIUM | LARGE

Circuit Description

The aftertreatment system is monitored by three temperature sensors that are located in the exhaust system. The aftertreatment diesel oxidation catalyst (DOC) inlet temperature sensor is located after the turbocharger outlet, at the inlet of the aftertreatment system. The aftertreatment diesel particulate filter inlet temperature sensor is located between the aftertreatment diesel oxidation catalyst and the aftertreatment diesel particulate filter. The aftertreatment diesel particulate filter outlet temperature sensor is located after the aftertreatment diesel particulate filter. The temperature sensors around the aftertreatment diesel oxidation catalyst are used to monitor the temperature differential across the catalyst during active regeneration of the aftertreatment system.

Component Location

The aftertreatment diesel oxidation catalyst is located in the exhaust system. The location of the catalyst can vary, depending on the original equipment manufacturer (OEM). Refer to the OEM service manual.

Conditions for Running the Diagnostics

• Active regeneration of the aftertreatment diesel particulate filter must be occurring before the diagnostic will run.

Conditions for Setting the Fault Codes

The electronic control module (ECM) has calculated DOC efficiency to be less than required to successfully complete a regeneration. 

Action Taken When the Fault Code is Active

• The ECM logs the fault code immediately when the diagnostic runs and fails.

Conditions for Clearing the Fault Code

The fault code will be set to inactive after performing INSITE™ electronic service tool Aftertreatment Diesel Particulate Filter regeneration test and the DOC efficiency is determined to be above a calibratible threshold.

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. Refer to Procedure 019-032 in Section 19.

This fault code is logged when the electronic control module (ECM) has calculated DOC efficiency to be less than required to successfully complete a regeneration.

Possible causes of this fault code include:

• Soot plugging the front face of the aftertreatment diesel oxidation catalyst
• Engine oil or fuel contamination of the aftertreatment diesel oxidation catalyst
• Cracked or contaminated aftertreatment diesel oxidation catalyst
• Damage in the aftertreatment fuel injection system
• Leaking exhaust system between the turbocharger and the diesel oxidation catalyst
• An in-range malfunction of the aftertreatment diesel oxidation catalyst or the aftertreatment diesel particulate filter inlet temperature sensor can cause this fault code. Make sure there are not any fault codes related to the aftertreatment temperature sensors before following this troubleshooting tree.

Refer to Troubleshooting Fault Code t05-2638