CM871 and CM876 Electronic Control Systems, ISX and ISM Engines – FAULT CODE 1663

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Overview

ISX and ISM – Aftertreatment Temperature Sensors 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 inlet temperature sensor is located after the turbocharger outlet. The aftertreatment diesel particulate filter inlet temperature sensor is located between the aftertreatment catalyst and aftertreatment particulate filter. The aftertreatment diesel particulate filter outlet temperature sensor is located after the aftertreatment particulate filter. These sensors monitor the temperatures in the aftertreatment system and determine is the aftertreatment catalyst is missing.

Component Location

The aftertreatment temperature sensors are located in the aftertreatment system. Refer to the original equipment manufacturer (OEM) troubleshooting and repair manual for specific exhaust gas temperature sensor locations.

Conditions for Running the Diagnostics

This diagnostic runs when the aftertreatment system is actively regenerating the diesel particulate filter.

This diagnostic also runs during engine warm-up.

Conditions for Setting the Fault Codes

The electronic control module (ECM) detects the aftertreatment diesel oxidation catalyst inlet temperature reading is higher than the aftertreatment diesel particulate filter inlet temperature during an active regeneration event of the diesel particulate filter.

Action Taken When the Fault Code is Active

• The ECM illuminates the amber CHECK ENGINE light immediately when the diagnostic runs and fails.
• 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 fault code will be set inactive following a key cycle if the fault was triggered during a regeneration event. If the fault code is active at key-on, allow the aftertreatment temperatures to cool below 32°C [90°F] and then start and run the engine at high idle for 10 minutes to clear the fault code.

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 activated when the ECM determines that the temperature reading from the aftertreatment diesel oxidation catalyst inlet temperature sensor and the aftertreatment diesel particulate filter inlet temperature sensor are reading backwards. The most likely cause of this fault code is that the aftertreatment diesel oxidation catalyst inlet temperature sensor and the aftertreatment diesel particulate filter inlet temperature sensor connectors are swapped at the OEM harness.

The diesel oxidation catalyst inlet temperature sensor and the diesel particulate filter outlet temperature sensor have the same part number and electrical connections. The diesel particulate filter inlet temperature sensor has a different connector key to prevent it from being swapped with the other temperature sensors. Verify the aftertreatment temperature sensors are correctly installed.

An in-range failure of the aftertreatment diesel oxidation catalyst or the aftertreatment diesel particulate filter inlet temperature 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 t05-1663