|  |  | Results
of the tests | 
| 1 | CHECK HIGH TEMPERATURE SWITCH/SIGNAL | All OK | Problems met | Operation | 
|---|
|  | 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 3 | Signal not present | Continue to Step  2 | 
| Connections broken | Restore connection between switch and instrument See   E5050  DIESEL ENGINES ELECTRONIC MANAGEMENT | 
| 2 | CHECK TEMPERATURE SENSOR | All OK | Problems met | Operation | 
|---|
|  | Check
the engine temperature sender unit See Test   1060E  Checking engine coolant temperature sensor operation | Continue to Step 3 | Sensor faulty | Replace the sensor Op.   1060G14 | 
| 3 | CHECK INSTRUMENT | All OK | Problems met | Operation | 
|---|
|  | 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 4 | Instrument not working | Change the instrument Op.   5560B10 | 
| 4 | CHECKING CORRECT OPERATION | All OK | Problems met | Operation | 
|---|
|  | Check
that the fault is no longer present | End of diagnosis | Fault persists | Search for the
fault starting from another symptom' |