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Removing and installing cooling system components
Fan run-on for cooling injectors
Engine Code: 2H
The engine is equipped with the following components for cooling the injection manifold and the injectors after engine has been shut down hot:
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◆ Thermo-switch -F87- in the vicinity of the injector
- Switching temperature:
- on = over 110 °C - continuity
- off = below 103 °C - continuity
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◆ Control unit -J138- at relay holder 14 of the fuse holder/relay plate
After the ignition has been switched off the control unit remains ready for operation for 10...12 minutes.
Should the temperature in the vicinity of the injectors rise to above 110 °C after the engine has been switched off hot, the thermo-switch connects the control unit to earth (-). The control unit the switches on stage 1 of the radiator fan. Once the temperature sinks to 103 °C the earth connection through the thermo-switch is interrupted and the fan is turned off. Heat accumulation in the engine compartment can cause this cycle to occur several times consecutively.
Checking Control Unit/Fan Run-On
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‒ Switch ignition on and off.
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‒ Connect thermo-switch wire -F87- to earth.
The fan should run at 1st stage.
Note:
As the control unit remains operational only for a period of 10...12 minutes after the ignition has been switched on and off, testing must be performed within this period.
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