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 sensorNumber plate light not working
Fault codes
Dds: no fault code displayed.
Dashboard: no fault code displayed.
Location of connections and components
Location of rear turn indicator and number plate light connection.
pin numbering for wiring harness side dashboard connector.
Checks
The number plate light receives p ...
Symbols - abbreviations - references
To allow quick and easy consultation, this manual uses graphic symbols to
highlight situations in which maximum care is
required, as well as practical advice or information. Pay attention to the
meaning of the symbols since they serve to avoid
repeating technical concepts or safety warnings th ...
Anti-pollution system and auto-adaptive strategy
Efficacy of the catalytic converter and oxygen sensors
To comply with current emissions legislation, the diavel is equipped with a
trivalent catalytic converter, which oxidises co
(carbon monoxide) and hc (unburnt hydrocarbons) and reduces nox (nitrogen
oxides).
The image shows the exhaus ...