TROUBLESHOOTING 124 All information subject to change without notice. (Rev. 04/08) DDC-SVC-MAN-0040 0704 Copyright © 2008 DETROIT DIESEL CORPORATION Problem—The Engine Fan Is Constantly On Cause Remedy The fan override switch is on. Check the operation of the fan override switch. The fan hub is damaged. Replace the fan hub The parameter settings in the MCM or CPC are incorrect. Have an authorized repair facility reprogram the control unit. Problem—Fuel Consumption Is Too High Cause Remedy The tires are not properly inflated. Check all tires for correct pressure. The air filter and/or intake air system is clogged. Check the air restriction indicator.
Clean the intake air system and replace the air filter if necessary. The exhaust brake valve is malfunctioning. Have an authorized repair facility check the operation of the valve.