Catalyst Missing – Condition Exists
|Fault Code: 1664
Catalyst Missing – Condition Exists. The aftertreatment catalyst in the exhaust system is not present.
Active aftertreatment diesel particulate filter regeneration will be disabled.
ISX and ISM – Aftertreatment Temperature Sensors
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 if the aftertreatment catalyst is missing.
The aftertreatment 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 troubleshooting and repair manual.
Conditions for Running the Diagnostics
This diagnostic runs when the aftertreatment system is being actively regenerated to reduce soot in the aftertreatment diesel particulate filter. The diagnostic checks for a temperature increase across the catalyst during an active regeneration of the aftertreatment system to detect the presence of the catalyst.
Conditions for Setting the Fault Codes
The electronic control module (ECM) detects that the aftertreatment diesel oxidation catalyst inlet temperature sensor and the aftertreatment diesel particulate filter inlet temperature sensor are reading the same temperature during an active regeneration of the aftertreatment system.
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 system 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, or at the next key-on.
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 becomes active when the aftertreatment diesel oxidation catalyst inlet and aftertreatment diesel particulate filter inlet temperature sensors do not detect the presence of a catalyst in the aftertreatment system. This can be caused by tampering with the catalyst system, the catalyst has been removed from the vehicle, or a damaged catalyst.