Engine Coolant Temperature – Condition Exists
|Fault Code: 2646
Engine Coolant Temperature – Condition Exists. The EGR valve was closed to reduce engine coolant temperature.
EGR valve actuation will be disabled.
ISB, ISC, ISL – Engine Coolant Temperature Circuit
When the engine coolant temperature nears the engine protection limits, the exhaust gas recirculation (EGR) valve will be closed to reduce the coolant temperature. This fault code is used as an information fault code, only indicating that the EGR valve has closed.
The engine coolant temperature sensor is located on the thermostat housing. Refer to Procedure 100-002 (Engine Diagrams) in Section E for a detailed component location view.
Conditions for Running the Diagnostics
This diagnostic runs continuously when engine speed is greater than 500 rpm.
Conditions for Setting the Fault Codes
The fault code is set active when the EGR valve is closed to reduce engine coolant temperature.
Action Taken When the Fault Code is Active
- The ECM illuminates the amber CHECK ENGINE light immediately when the diagnostic runs and fails.
Conditions for Clearing the Fault Code
The fault code is set inactive when the EGR valve actuation is re-activated.
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.
When the engine coolant temperature nears the engine protection limits, the EGR valve will be closed to reduce the coolant temperature. This fault code is used as an information fault code, only indicating that the EGR valve has closed. No failure has occurred to cause this fault code. Other engine protection fault codes will be active if the engine coolant temperature has exceeded the engine protection limits.