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.
Key-on/key-off using the key on the hands free lock with the passive key
Key-on can be performed by pressing the button (7) on the
hands free lock and with the presence of the passive key (4,
fig. 77).
Note
The passive key (4, fig. 77) Has a range of a few cm,
therefore the key (4, fig. 77) Must be positioned near the
antenna (2). Remove the seat (see "remova ...
Fuel system circuit
The fuel system circuit consists of:
An electric pump, driven by the injection relay, which is in turn
controlled by the ecu (engine control unit)
A fuel filter
A pressure regulator
Two injectors (one per cylinder, located downstream of throttle valve)
The plastic mounting shown in t ...
Removal of the tool tray
To remove the tool tray unit from the lateral footrests, loosen the screws
(40) and remove the splashguard (20).
Undo the screws (15) and remove the cover (16).
Move the wiring branch from the seat (s) on the tool tray.
Loosen the screws (24) to remove the tool tray unit (23) from ...