Fan drive belt is broken
Check the fan drive belt. Replace the belt, if necessary. Refer to Procedure 008-002.
Fan drive belt is loose
Check the belt tension and tighten if necessary. Refer to Procedure 008-002.
Cold weather radiator cover or winterfront is closed
Open the cold weather radiator cover or the winterfront. Refer to the OEM service manual
Radiator shutters are not opening completely, or the shutterstat setting is wrong
Inspect the radiator shutters. Repair or replace if necessary. Check the shutterstat setting. Refer to
the OEM service manual.
Charge air cooler fins, radiator fins, or air conditioner condenser fins are damaged or obstructed with debris
Inspect the charge air cooler, air conditioner condenser, and radiator fins. Clean, if necessary.
Refer to Procedure 010-027.
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.
Intake manifold air temperature sensor has an in- range failure
Check the intake manifold air temperature sensors that correspond to the fault code. Replace the
sensor if necessary. Refer to Procedure 019-159 of the Troubleshooting and Repair Manual, CM2100 and CM2150 Electronic Control System, Bulletin 4021570, to monitor and check the manifold temperature sensor.
Programmable parameters or selected features are not correct
Check the programmable parameters and the selected features with an electronic service tool.
Set the parameters and features again if necessary. Refer to Procedure 019-078 in the
Troubleshooting and Repair Manual, CM21 00 and CM2150 Electronic Control System, Bulletin
4021570.
Fan drive or fan controls are malfunctioning
Check the fan drive and controls. Refer to Procedure 008-026 if electronically controlled by
the engines’s ECM. If OEM controlled see the OEM service manual.
Fan is not correct
Check the fan part number and compare it to the OEM-specified part number. Replace fan if necessary. Refer to the OEM service manual.
Fan shroud is damaged or missing or the air recirculation baffles are damaged or missing
Inspect the shroud and the recirculation baffles. Repair, replace, or install, if necessary. Refer to
Procedure 008-038.
Vehicle speed is too low for adequate cooling with high engine load
Reduce the engine load. Increase the engine (fan) rpm by downshifting.
Exhaust system leaking hot air into engine compartment
Check the exhaust plumbing for leaks or broken components. Refer to Procedure 010-024.
Intake manifold pressure (boost) sensor or circuit is malfunctioning
Check the boost sensor and circuit. Compare the intake manifold pressure sensor reading in the
monitor mode using INSITETM to a manual pressure gauge. Refer to Procedure 019-159 in the
Troubleshooting and Repair Manual, CM21 00 and CM2150 Electronic Control System, Bulletin
4021570.
EGR valve is leaking
Check the EGR valve for leaks. Refer to Procedure 011-022
EGR cooler malfunctioning
Check the EGR cooler. Refer to Procedure 011-019.
Vehicle cooling system is not adequate
Verify that the engine and vehicle cooling systems are using the correct components. Refer to the
OEM service manual.
Fan is not an adequate size for the application
Verify that the fan is the correct size. Refer to the OEM service manual.
