MBE 4000 SERVICE MANUAL 6SE412 All information subject to change without notice. (Rev. 2007) 6SE412 0702 Copyright © 2007 DETROIT DIESEL CORPORATION From Bulletin 1–MBE 4000–07 16-7 Problem—The Engine Is in Emergency Running Mode (constant speed 1,300 rpm) Cause Remedy The PLD or VCU control unit is damaged. Bring the vehicle to an authorized dealer for service. Problem—The Coolant Temperature Is Above Normal Cause Remedy The coolant level is too low. Check for coolant leaks, and repair as needed. The poly-V belt is loose. Tighten or replace the poly-V belt. The coolant temperature gauge and/or sensor is not reading correctly. Bring the vehicle to an authorized dealer for service.
The radiator is damaged or dirty. Clean the radiator. Repair or replace the radiator if necessary. The coolant pump is damaged. Have an authorized dealer replace the coolant pump. The thermostat is damaged. Have an authorized dealer replace the coolant pump. The fan is not operating properly. Bring the vehicle to an authorized dealer and have the fan hub checked. Bring the vehicle to an authorized dealer and have the parameter settings reprogrammed in the engine control unit (PLD) or vehicle control unit (VCU). Problem—The Coolant Temperature Is Below Normal Cause Remedy The coolant temperature gauge and/or sensor is not reading correctly.
Bring the vehicle to an authorized dealer for service. The thermostat is damaged. Have an authorized dealer replace the thermostat. The fan is not operating properly. Bring the vehicle to an authorized dealer and have the fan hub checked. Bring the vehicle to an authorized dealer and have the parameter settings reprogrammed in the engine control unit (PLD) or vehicle control unit (VCU). Problem—The Cooling System Is Losing Coolant Cause Remedy There is an external coolant leak. Repair the leaking component. The radiator cap is leaking. Replace the radiator cap. The air compressor head is damaged. Have an authorized dealer replace the air compressor. The cylinder head gasket is leaking.
Have an authorized dealer replace the head gasket.