B5.9G, B5.9LPG, B Gas Plus, B LPG Plus – Coolant Temperature Above Normal – Sudden Overheat

Symptom Tree  

Electronic fault codes are active

For instructions on how to read active fault codes, refer to Procedure 101-007 (Electronic Controlled Fuel Systems) Section 1 and a Cummins Authorized Repair Facility. If fault codes are active, contact a Cummins Authorized Repair Facility.


Fan drive belt is broken

Check the fan drive belt. Replace the belt, if necessary. Refer to Procedure 008-002 ( Drive Belt, Cooling Fan) in Section A.


Coolant level is below specification

Inspect the engine and cooling system for external coolant leaks. Repair if necessary. Add coolant. Refer to Procedure 008-066 (Coolant Level) in Section 3.


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 (Charge-Air Cooler) in Section 5 and Procedure 010-027 (Charge-Air Cooler) in Section A.


Radiator cap is not correct, is malfunctioning, or has low-pressure rating

Check the radiator pressure cap. Refer to the OEM service manual.


Coolant temperature gauge is malfunctioning

Test the temperature gauge. Repair or replace the gauge, if necessary.


Transmission retarder use is excessive

Reduce the use of the transmission retarder.

Contact a Cummins Authorized Repair Facility

Last Modified:  15-Feb-2005