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 sensorTips for use on the track
We recommend level 8 be used for a couple of full laps (to
allow the tyres to warm up) in order to get used to the
system. Then try levels 7, 6, etc., In succession until you
identify the dtc intervention level that suits you best (always
try each level for at least two laps to allow the tyres t ...
Removal of the starter motor idler gear
Slide the gear pin (21) complete with the gear (19) and washer (20).
Warning
Pay attention to the washer (20) since it may fall inside the
crankcase half.
At this point, it is possible to remove the starter motor as described in
sect. 6 - 3, Starter motor. ...
Indication of range reached for service
When service coupon threshold is achieved, upon every key-on the system
displays the indication of the type of
intervention that is required (oil service or desmo service).
The (red) warning is activated as a large icon for 10 seconds upon every key-on
(1) then as a small warning that
remai ...