3.2.36. SPN 110, FMI 16, Coolant temperature ABOVE NORMAL

Description

The measured coolant temperature exceeds the overheating warning limit.

Possible causes are:

• The fan belt is slipping, or the belt is broken.
• The cooling system is not completely filled.
• The water pump is defective.
• The cooling system is clogged.
• The thermostat is defective or removed (a double acting thermostat).
• The thermostat is upside down.
• The radiator filler cap is not pressure tight.
• The engine is overloaded.
• The coolant temperature sensor wiring is defective.
• The coolant temperature sensor is defective.

Reaction in EEM

The FC is stored and the warning lamp is activated. The engine power will be reduced (Fuel limiting) above the warning limit to prevent overheating of the engine. The CAN message indicates active fault.

Solution

Find cause for the overheating indication:

• Check the fan belt and the belt tension.
• Check the coolant level.
• Check the condition of the radiator.
• Check the mechanical condition of the engine.

To check the electrical defects, check the coolant temperature sensor, the sensor wiring and the controller input: First save the error log and then erase it. Restart the ECU after erasing the error log. If the fault occurs again during the next driving cycle, check the following paths:

• Check the coolant temperature sensor wiring, the connectors and the contact surfaces of the connector pins (possible oxidation).
• Check the operation with another coolant temperature sensor to see if the temperature sensor is defective.

See Coolant temperature sensor for reference.