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 sensorKey-on/key-off using the key on the hands free lock with the active key
Key-on can be performed by pressing the button (7) on the
hands free lock (1, fig. 77) And with the presence of the
active key (3, fig. 77).
Note
The active key (3, fig. 77) Has a range of approx. 1.5 M,
therefore it must be located within this range.
Key-off can be performed by pressing the ...
Inspection of the gear selector forks
Visually inspect the gear selector forks. Bent forks must be renewed as they
may lead to difficulties in gear changing or
may suddenly disengage when under load.
Use a feeler gauge to check the clearance of each fork in its gear groove.
If the service limit has been exceeded, check whether ...
Overhaul of the crankcase halves
Carefully examine the engine crankcase halves.
Check that the surfaces of the crankcase halves are perfectly flat using a
reference surface.
Check that the bearings (1) and (18), and the bushings (2) and (17) are in
optimum conditions. Note that the main
bearings must always be changed in p ...