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 sensorTrip 1 meter
This function shows the distance travelled since the trip
meter was last reset (in km or miles depending on the
specific application).
Holding the button (1, fig. 14)
pressed for 3 seconds
when this function is displayed resets the trip meter.
When the reading exceeds 9999.9, Distance tr ...
Overhaul of the connecting rods
Make the following dimensional checks on the connecting rods:
Clearance with gudgeon pin on assembly.
In the event of excessive wear (sect. 3 - 1.1, Crankshaft), replace the
connecting rod.
The small end bushing must be in good condition and firmly driven into its seat.
Check for para ...
Removing the timing belt driveshaft pulleys
Use the tool code 88713.1805 To hold the driving pulley on the engine
crankcase against rotation.
Important
If this operation is carried out with the engine installed in the frame,
hold the driveshaft pulleys against rotation using the
tool code 88713.2011 Mounted on the alternator cover.
Lo ...