939003637 - K026 ENGINE COOLANT OVERHEATING WARNING LIGHT NOT WORKING

With the ignition on, the engine coolant temperature gauge on the instrument panel is not working
the engine temperature and the engine temperature sensor signal is made available by the "engine management node" via the C-CAN; the "body computer node" makes the message available on the B-CAN via the gateway and then to the instrument panel.
0PRELIMINARY CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Check that the engine control warning light does not come on with the engine startedMove on to Step 2Warning light onMove on to Step 1
1CHECK USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION
Connect the Examiner diagnostic equipment to the diagnostic socket.Check for faults in the Engine Control NodeMove on to Step 2Presence of faultsContinue as described by the diagnostic equipment
2CHECK FOR ENGINE CONTROL FAULTSALL OKPROBLEMS ENCOUNTEREDACTION
The panel indicates errors not detected by the engine control unit: proceed as instructed in the    See table K101 MIL WARNING LIGHT STAYS ON (ENGINE STARTS) End of diagnosis
3CHECK USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION
Keeping the Examiner connected to the diagnostic socket, check the operation of the warning light on the instrument panel by means of active diagnosisMove on to Step 41. The warning light does not come on for the serial line with the NQS interrupted1. Move on to Step 4
2. Instrument power supply interrupted2. Move on to Step 5
4SERIAL LINE CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Check the continuity/insulation of the serial line between the auxiliary gauge and the instrument panel by peforming the Test    See Test 5560BW CHECK AUXILIARY INSTRUMENTSMove on to Step 5Serial line brokenRestore the serial line
5SUPPLY CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Check that the auxiliary gauge is correctly supplied by conducting the Test    See Test 5560BW CHECK AUXILIARY INSTRUMENTSMove on to Step 61. Power supply interrupted1. Restore power supply
2. Auxiliary instrument defective2. Replace the gauge    Op. 5560C51 COMBINED ANALOGUE CONTROL PANEL - R+R OR REPLACE
6ELECTRICAL CIRCUIT CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Check the continuity/insulation of the cable between the engine coolant temperature sensor, engine control unit, Body Computer and instrument panel    See E5030 PETROL ENGINES ELECTRONIC MANAGEMENT Move on to Step 7Connections broken/not insulatedRestore cable continuity/insulation
7CHECK ON CORRECT OPERATIONALL OKPROBLEMS ENCOUNTEREDACTION
Check that the fault is no longer presentEnd of diagnosisThe fault persistsReplace Body Computer    Op. 5505A32 BODY COMPUTER - R.R