2888396 - K26 ENGINE COOLANT OVERHEATING WARNING LIGHT NOT WORKING

With the ignition turned ON, the engine coolant temperature warning light does not come on when the engine is very hot.
Results of the tests
1CHECK HIGH TEMPERATURE SWITCH/SIGNALAll OKProblems metOperation
Connect the diagnostic equipment (Examiner or other instruments) to the diagnostic socketCarry out active diagnosis of the maximum engine coolant temperature warning light (through the engine management control unit) Continue to Step 2Signal not presentContinue to Step 2
Connections brokenRestore connection between switch and instrument See   E5030  PETROL ENGINE ELECTRONIC MANAGEMENT
2CHECK TEMPERATURE SENSORAll OKProblems metOperation
Check the engine temperature sender unit See Test   1056C  Checking engine coolant temperature sensor operation Continue to Step 3Sensor faultyReplace the sensor Op.   1056B50 
3CHECK INSTRUMENTAll OKProblems metOperation
Check the condition of the high engine coolant temperature warning light, located in the instrument see DESCRIPTION AND OPERATION: 5560 INSTRUMENT PANEL
The warning lights consist of LEDs built into the electronic circuit, and so CANNOT be replaced.
Continue to Step 4Instrument not workingChange the instrument Op.   5560B10 
4CHECKING CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisFault persistsSearch for the fault starting from another symptom'