Engine is operating at low ambient temperature
Check the winterfront, shutters, and under-the- hood air. Use under-the-hood intake air in cold weather. Refer to the OEM service manual.
Electronic fault codes active or high counts of inactive fault codes
View and troubleshoot the fault codes with INSITETM. Refer to the Troubleshooting and Repair
Manual, CM21 00 and CM2150 Electronic Control System, Bulletin 4021570.
Coolant temperature gauge or sensor is malfunctioning
Test the gauge and the sensor. Repair or replace, if necessary. Refer to the OEM service manual.
Coolant temperature gauge or sensor is malfunctioning
Test the gauge and the sensor. Repair or replace, if necessary. Refer to the OEM service manual
instructions on troubleshooting the gauge. Refer to the Troubleshooting and Repair Manual, CM21 00 and CM2150 Electronic Control System, Bulletin 4021570, to monitor and check the coolant
temperature sensor.
Thermostat is not correct or is malfunctioning
Check the thermostat for the correct part number and for correct operation. Refer to Procedure
008-013.
Fan drive or fan controls are malfunctioning
Check the fan drive and controls. Refer to Procedure 008-026 if electronically controlled by
he engine’s ECM. If OEM controlled, refer to the OEM service manual.
Engine idle time is excessive
Low oil and coolant temperatures can be caused by long idle time (greater than 10 minutes). Shut
off the engine rather than idle for long periods. If idle time is necessary, raise the idle speed.
Procedure 008-026 if electronically controlled by the engine’s ECM. If OEM controlled, refer to the
OEM service manual.
Cooling system component is malfunctioning
Perform the cooling system diagnostics test. Refer to Procedure 008-020.