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 to modify the fuel-air mixture and ignition advance in relation to the atmospheric air temperature.
Components assembling position

The air temperature sensor is mounted on the right hand air intake (the image also shows the location of the connection).
Wiring diagram

Ccm engine control connection, s air temperature sensor. 1 Green/blue - g/b, 2 black/purple - bk/v.
In the event of fault
In the event of an air temperature sensor fault, the engine control unit implements a recovery value of 25C.
Fault codes generated and possible correlated faults
Fault codes generated by the engine control unit and displayed by the dds (intake air temperature sensor 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 "air temperature" and the eobd warning light activates.
Possible correlated faults: inadequate engine power, irregular idle speed (target idle speed is 1350 rpm with engine stabilised at operating temperature), the engine does not start easily. Check: -sensor resistance, which must be approximately 2 kohm at 25 C.
The air temperature value may be checked using the dds. Check that the value given is plausible.
If none of the aforementioned tests identify the problem and the air temperature sensor is in proper working order, replace the engine control unit.
Component replacement methods
No special measures are necessary in order to replace the air temperature sensor.
Component assembling position
Engine temperature sensorSteering head: steering
Screw
Steering head
Screw
Lower rh u-bolt
Lower lh u-bolt
Bearing
Screw
Sealing ring
Washer
Spacer
Washer
Nut
Washer
Screw
Bottom yoke
Dowel
Nut
Screw
Special screw
Clip nut
Left-hand support
Front splashguard
Right-hand support
Front support
S ...
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 ...
Ignition coils
Introduction
The engine control system of the diavel includes two ignition coils: one for
the horizontal cylinder and one for the vertical
cylinder. These coils are installed directly in the spark plug wells. A diode is
installed on the secondary winding inside the
coil, which prevents the un ...