Introduction
The radiator fans are powered via a specific relay, which is enabled by the engine control unit.
Component assembling position

A injection relay; b etv relay (throttle valve actuator motor), c radiator fan relay, d engine control unit.

Location of right hand fan connection.

Location of left hand fan connection.
Connection wiring diagram

Ccm engine control connection, t radiator fan relay, a key on power (+15 from hands free relay 30), r battery power (+30), l left hand fan, r right hand fan, 85 light blue/black - lb/bk, 30 red/green - r/g, 86 red/black - r/bk, 87 red/grey - r/gr.
In the event of fault
In the event of a radiator fan relay fault, the radiator fans themselves do not work. The relay is not commanded by the ecu.
Fault codes generated and possible correlated faults fault codes generated by the engine control unit and displayed by the dds (fan relay diagnosis):
Note
Check integrity of electric circuit - short-circuit to vdc = with dashboard on, using a voltmeter, a voltage is measured between the wire tested and ground.
Check integrity of electric circuit - short-circuit to ground = with the battery cables disconnected, using an ohmmeter, continuity is detected between the wire tested and ground.
Check integrity of electric circuit - open circuit = with the battery cables disconnected, using an ohmmeter, no continuity is detected between the two ends of the wire tested.
The dashboard service display shows the error "fan relay" and the eobd warning light activates.
Possible correlated faults: coolant reaches boiling point but radiator fans not working. Check:
The radiator fan relay may be actuated from the dds to check radiator fan function.
The fans are normally activated at 103 and switched off at 101C.
If none of the aforementioned tests identify the problem and the radiator fan relay is in proper working order, replace the engine control unit.
Component replacement methods
No special measures are necessary in order to replace the radiator fan relay.
Starter motor relay
Engine speed-timing sensorResidual range indication when the service is due
After resetting the first oil service warning (triggered at 1000 km), upon
every key-on the system displays the
indication of which type of service should be performed next (oil service or
desmo service) and the residual range.
A (green) warning (1) is activated for 2 seconds on every key-on ...
First warning - oil service 1000 km
The first warning is activated at 1000 km (600 miles) of odometer reading.
The (red) warning is activated as a large icon for 10 seconds upon every key-on
(1) then as a small warning that
remains displayed (2) until it is reset.
...
Air temperature sensor
Introduction
The engine control system on the diavel uses a sensor that measures air
temperature. This sensor has a resistance of
ntc type (negative temperature coefficient), that reduces its own value when the
temperature increases. The air
temperature sensor allows the engine control unit t ...