42161 Mercury LINK

Probable Causes
Cold mode
Diagnostic trouble codes
Flash file
Starting aids
Fuel supply
Cooling system
Engine speed/timing
Unit injectors
Component wearRecommended Actions
Cold Mode
Excessive white smoke emissions may occur during cold mode operation of the engine. During cold mode operation of the engine, the Electronic Control Module (ECM) may modify the injection timing and the ECM may cut out certain engine cylinders. This will increase startability and this will reduce warm up time. Cold mode is activated whenever the engine coolant temperature falls below a predetermined value. Cold mode remains active until the engine has warmed or a time limit is exceeded.Diagnostic Trouble Codes
Establish communication between Caterpillar Electronic Technician (ET) and the ECM. Verify that the communications adapter is communicating on both data links.Check for active codes. Look for active codes that are related to the high pressure fuel system and the low pressure fuel system. Troubleshoot any active codes before continuing with this procedure.Flash File
Verify that the correct flash file is installed. Refer to Troubleshooting, "ECM Software - Install".Starting Aids (If Applicable)
If a jacket water heater is installed on your application, check for proper operation of the circuit. Repair the circuit for the jacket water heater, if necessary.
If the application has an ether injection system, ensure that the ether canister is not empty or low. Replace the ether canister if the ether canister is empty or low. If an electrical problem with the ether injection system is suspected, refer to the particular test procedure for your application. Fuel Supply
Contact with high pressure fuel may cause fluid penetration and burn hazards. High pressure fuel spray may cause a fire hazard. Failure to follow these inspection, maintenance and service instructions may cause personal injury or death.
Do not loosen any high pressure fuel lines when the engine is running. The high pressure in the fuel lines can cause personal injury or death. Wait 60 seconds after the engine has stopped to allow pressure to purge before any service or repair is performed on the engine fuel lines.
Check the fuel pressure during engine cranking. Check the filtered fuel pressure. If the fuel pressure is low, replace the fuel filters. Refer to Systems Operation/Testing and Adjusting, "Fuel System Pressure - Test".
Cold weather adversely affects the characteristics of the fuel. Refer to the Operation and Maintenance Manual for information on improving the characteristics of the fuel during cold weather operation. Cooling System
Check for an internal coolant leak into a cylinder and/or the exhaust. Refer to Systems Operation/Testing and Adjusting for information on inspecting the cooling system.Ensure that the temperature readings for the sensor are reasonable for the conditions that are present.Engine Speed/Timing
Check the calibration of the engine speed/timing sensor. Refer to Troubleshooting, "Timing - Calibrate".Unit Injectors
Perform the "Cylinder Cutout Test" on Cat ET in order to try to isolate any cylinders that may be misfiring. A misfiring cylinder could be related to an injector that is worn or in poor repair. Refer to Troubleshooting, "Injector Solenoid - Test".Component Wear
Check the valve lash and reset the valve lash, if necessary. Refer to Systems Operation/Testing and Adjusting.
Possible causes of low compression are shown in the following list:
Faulty piston
Faulty piston rings
Worn cylinder bores
Worn valves
Faulty cylinder head gasket
Damaged cylinder head