Left vent temperature sender -G150
A - Connector of temperature sensor -G150
B - Left vent temperature sender -G150
C - Sealing ring
The air conditioner is regulated within an
overall temperature range between 18°C and 28°C. However, the possibilities of
individual climate settings for each selectable position must be set against
the fact that the climate zones are not physically separated from each other.
In the selected automatic function the air
conditioner uses the sensors to determine how much the air for the climate zone
concerned needs to be heated or cooled in order to deliver the selected
The Climatronic control unit decides based on
the request for example that regulated warm or cooled air should be routed into
the driver or front passenger climate zone as
appropriate to provide ventilation.
The climate control is fully automatic, with separate air
temperature control for the left and right sides of the passenger compartment.
The left vent temperature sender -G150 is
located in the air duct to the left side dash panel vent.
The air flowing out of the heater/air
conditioner unit into the passenger compartment is recorded with a
temperature-dependent resistance and so is available as an influencing variable
in the temperature monitoring and control function of the Climatronic control
temperature sender -G150 is designed as an NTC sensor. The resistance is
evaluated as a signal from the control unit and regulates the air distribution
and delivery rate of the blower.
J The value of the outflow temperature is
determined as a reference signal to the dash panel temperature sensor -G56 on
the right and left sides.
J As the temperature falls the electrical
J The sender is self-diagnosis compatible. A fault detected in the
sender is only registered by the Climatronic control unit -J255 if the coolant
temperature is detected as above 50°C.
J If the fault: "short to
earth" is detected by the Climatronic control unit -J255, the value 150°C
is entered in display zone 3 of measured value block 9.
J If the fault: open circuit/short to
positive is detected by the Climatronic control unit -J255, the value -70°C is
entered in display zone 3 of measured value block 9.
J If the left vent temperature sender -G150 fails,
the value of the intact vent temperature sender -G151 is adopted. Operation is maintained.
J Experience shows that temperature senders are
the most frequent cause of temperature control faults. They do not usually fail
immediately, but deliver false values to the control unit based on an
additional wire resistance as a result of damage or corrosion in the connector
contacts. Thus a comparison of the values of all senders (-G150, -G151, G261
and -G262) in the relevant display zones is recommended for optimum diagnosis.
A Air conditioner; Rep.Gr. 87; Removing and
installing left vent temperature sender -G150
A Current flow diagram; ELSA
Measured value block 9
Display zone 1:
Readout of vent temperature sender, left
footwell -G261 in °C
Display zone 2:
Readout of vent temperature sender, right
footwell -G262 in °C
Display zone 3:
Readout of left vent temperature sender -G150 in
Display zone 4:
Readout of right vent temperature sender -G151