Source: https://www.pdfmanual4trucks.com/volvo/mid-146-volvo-fh-ver-2-cabin-climate-control-unit-fault-codes/
Timestamp: 2019-04-23 09:01:15+00:00

Document:
The climate control unit registers the voltage in the temperature sensor circuit above 4.86 V. The sensor is not connected to the control unit. It is possible to short the signal or ground wire to a higher voltage.
The climate control unit registers the voltage in the temperature sensor circuit below 0.7 V. The signal wire is shorted to ground or the sensor is faulty.
The microclimate control unit registers the voltage in the temperature sensor circuit above 4.9 V. Closure of the signal or ground wire to a higher voltage. The sensor may be faulty.
The climate control unit registers the voltage in the temperature sensor circuit below 0.55 V. The signal wire is shorted to ground or the sensor is faulty.
Air temperature sensor (located between the evaporator and the fan).
The climate control unit registers the voltage in the temperature sensor circuit below 0.24 V. The signal wire is shorted to ground or the sensor is faulty.
Stepper motor controls damper external air flow and recirculation.
The climate control unit registers a short to ground. Shorting the signal wire of an electric motor to a lower voltage or ground.
Stepper motor controls air distribution flaps.
Stepper motor controls the air supply to bypass the heat exchanger.
Shorting the signal wire to a lower voltage or ground circuit.
Broken wire mass of the compressor clutch or defective clutch.
Coolant flow control valve through heat exchanger.
Shorting the signal or ground wire to a higher voltage.
Shorting the signal wire to ground.
Broken power wire, ground, defective fuse F32 or valve is faulty.
Air temperature sensor after the heat exchanger.
The climate control unit registers the voltage in the temperature sensor circuit above 4.9 V. The sensor is not connected to the control unit. It is possible to short the signal or ground wire to a higher voltage.
Micro-fan of the air temperature sensor in the cabin (combined with a temperature sensor).
Shorting the signal wire to a lower voltage or ground.
Shorting the signal wire of the corresponding phase of an electric motor to a higher voltage.
Refrigerant pressure sensor in the system.
The microclimate control unit registers a signal with a voltage higher than 4.5 V from the pressure sensor. The signal or ground wire is closed at a higher voltage.
The climate control unit registers a signal with a voltage below 0.3 V from a pressure sensor. The signal wire is shorted to ground, there is a wire break between the unit and the sensor, or the sensor is not connected to the connector.
Power supply 5 V. Refrigerant pressure sensor in the system.
The climate control unit registers the sensor supply voltage above 5.5 V. Closing the signal or ground wire to a higher voltage.
The climate control unit registers a short to ground. Shorting the signal wire to a lower voltage or ground.
Incorrect software, emergency interruption of the programming process, or the climate control unit is faulty.
Invalid information from other blocks. check fault codes in other control units.
The climate control unit registers the voltage above 4.86 V. The closure of the wires of the data channel to a higher voltage.
The climate control unit registers the voltage below 0.24 V. The closure of the wires of the data channel to ground.
Faulty data channel wires or faulty control unit.
The programming of the block is incorrect or the memory chip is faulty in the control unit. Reprogram the cabin climate control unit. In extreme cases, replace the control unit.
The main temperature sensor (located in the control unit and microclimate switches).
The climate control unit registers the voltage in the temperature sensor circuit above 4.95 V. Closing the signal or ground wire to a higher voltage. Replace climate control unit.
The climate control unit registers the voltage in the temperature sensor circuit below 0.05 V. Closing the signal wire to ground. Replace climate control unit.
Compensation temperature sensor ( located in the control unit and microclimate switches).
Compensation temperature sensor (located in the control unit and microclimate switches).
Solar radiation sensor (located in the control unit and microclimate switches).
Data Link Disruption SAE J1587 with engine control unit (MID128).
Communication with the engine control unit (MID128) interrupted for more than 60 seconds. There is no information about the temperature of the coolant and engine speed. Short or broken data channel SAE J1587. Check the integrity of the data channel, check the trouble codes in the engine control unit.
Data Link Disruption SAE J1587 with car control unit (MID144).
Communication with vehicle control unit (MID144) interrupted for more than 60 seconds. No information about the speed of the car. Short or broken data channel SAE J1587. Check the integrity of the data channel, check the trouble codes in the vehicle control unit.
Communication with the dashboard control unit (MID140) interrupted for more than 60 seconds. No information about outdoor temperature. Short or broken data channel SAE J1587. Check the integrity of the data channel, check the trouble codes in the dashboard control unit.

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