TROUBLESHOOTING 48 All information subject to change without notice. (Rev. 04/08) DDC-SVC-MAN-0055 04/08 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 DDEC-ECU or DDEC-VCU are incorrect. Have an authorized dealer 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 fuel filter is clogged. Replace the filter element. The exhaust brake valve is malfunctioning. Have an authorized dealer check the operation of the valve. The engine performs poorly, or does not develop full power. The remedies are listed in -48"The Engine Performs Poorly, Does Not Develop Full Power” in this section.