The blower and the heater controls and the A/C system do not work

The A/C compressor clutch and the A/C condenser/radiator fans are inoperative, but the blower and heater controls work

Probable cause: A/C pressure sensor circuit malfunction or evaporator temperature sensor circuit malfunction

Troubleshoot the A/C pressure sensor circuit:

NOTE: The A/C pressure sensor circuit can malfunction without setting a DTC

The A/C compressor clutch does not engage, but the A/C condenser/radiator fans operate, and the blower and heater controls work

The A/C condenser/radiator fans do not run at low speed with the A/C on, but the blower and heater controls work normally

The A/C condenser/radiator fans do not run at high speed, but do run at low speed with the A/C on

Probable cause: Malfunction in the fan(s) high speed circuit

Do the following troubleshooting as needed:

Blower fan runs slower than expected in cold weather (when in AUTO mode)

NOTE: It is normal for the blower fan to run slowly until the coolant temperature rises when in AUTO mode

Probable cause: Engine coolant temperature (ECT) circuit malfunction

Troubleshoot the ECT sensor circuit:

The A/C compressor clutch cycles rapidly on and off

Probable cause:

The A/C compressor clutch does not disengage when the A/C switch is off

Probable cause: The A/C compressor clutch circuit is on (energized) continuously, shorted to ground, stuck A/C compressor clutch relay, or the A/C compressor clutch is mechanically jammed

Do the A/C compressor clutch check, and repair any problems with the A/C compressor clutch

The A/C compressor relief valve. If it has vented refrigerant to the atmosphere, correct the problem with the A/C compressor clutch or the A/C compressor clutch circuit, then replace the A/C compressor relief valve

The A/C compressor relief valve has vented refrigerant

NOTE: This indicates the A/C system high side pressure was high

Probable cause: A high-side restriction, the A/C condenser/radiator fans are inoperative, or the A/C compressor clutch is not disengaging

Driver's and passenger's side vent temperatures vary by more than 20 °F (11 °C)

Probable cause:

HDS does not communicate with the climate control unit or the vehicle

A/C information does not display on the center display unit, but the blower, heater and A/C system controls work (climate control panel without display)

Probable cause: Communication malfunction between the audio unit^*1 or the audio-navigation unit^*2 and the climate control unit

Check the B-CAN line between the audio unit^*1 or the audio-navigation unit^*2 and the climate control unit

Insufficient heating