Group 87 Climate Control, Fault Codes
Troubleshooting
MID 146 PID 171 Temperature Sensor, Ambient Temperature
T3006581
T8009498
Component: A03 Instrument Cluster A34 Climate
Control Unit, B22 Sensor, Outdoor temperature
General information
The sensor measures the ambient air temperature outside
the cab. The sensor is located near the front bumper.
The sensor is connected directly to the Instrument Cluster
(A03) which then transmits the ambient temperature
data to the Climate Control Unit (A34) via the SAE
J-1587/J-1708 datalink.
Note: This fault code only applies to vehicles which
have an ambient temperature sensor. See Fault codes,
Instrument Cluster group 381 for further troubleshooting.
Error code
FMI 3
Abnormally high voltage or short-circuit to higher voltage.
Conditions for error code:
•
If the control unit detects a voltage higher than 4.9V
the control unit interprets this as an error and a fault
code is stored.
Possible cause:
•
Signal cable short-circuited to higher voltage
•
Ground lead short-circuited to higher voltage
•
Faulty sensor
Reaction from the control unit:
•
Fault code is stored
•
Yellow lamp requested
•
The control unit requests the ambient air temperature
from the instrument cluster
Noticeable external symptoms:
•
Yellow lamp lights up
FMI 4
Abnormally low voltage or short-circuit to lower voltage
Conditions for error code:
•
If the control unit detects a voltage lower than 0.55V
the control unit interprets this as an error and a fault
code is stored.
Possible cause:
•
Signal cable short-circuited to ground
•
Faulty sensor
Reaction from the control unit:
•
Fault code is stored
•
Yellow lamp requested
•
The control unit requests the ambient air temperature
from the instrument cluster
Noticeable external symptoms:
•
Yellow lamp lights up
•
Considerably reduced temperature control
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