HVAC SYSTEM (AUTO A/C) (DIAGNOSTICS) > Diagnostics with Phenomenon

INSPECTION

Symptom

Problem parts

A/C system fails to operate.

• Fuse (F/B No. 7, 22, 31).

• Connector (Poor contact)

• Ground

• Auto A/C control module

• Blower fan motor

• Blower fan relay

• A/C relay

• Compressor (Magnet clutch)

• Evaporator sensor

• Compressor (compressor speed sensor, diesel engine model)

Fuse is blown out.

• Fuse (F/B No. 7, 22, 31).

• Connector (Poor contact)

Illumination cannot dim.

• Fuse (F/B No. 7, 22, 31).

• Connector (Poor contact)

• Auto A/C control module

Blower fan does not rotate or fan speed cannot be controlled.

• Fuse (F/B No. 7, 22, 31).

• Connector (Poor contact)

• Ground

• Auto A/C control module

• Blower fan motor

• Blower fan relay

Unable to switch suction vents.

• Connector (Poor contact)

• Auto A/C control module

• Intake door actuator

Unable to switch vents.

• Connector (Poor contact)

• Auto A/C control module

• Mode door actuator

Room temperature does not rise (Warm air does not come out).

• Connector (Poor contact)

• Auto A/C control module

• Air mix door actuator

• In-vehicle sensor, ambient sensor, evaporator sensor and sunload sensor

• In-vehicle sensor aspirator hose

• PTC heater (diesel engine model)

Room temperature does not lower (Cold air does not come out).

• Connector (Poor contact)

• Auto A/C control module

• Air mix door actuator

• A/C relay

• Compressor (Magnet clutch)

• Radiator fan motor

• Radiator fan relay

• In-vehicle sensor, ambient sensor, evaporator sensor and sunload sensor

• In-vehicle sensor aspirator hose

• Compressor (compressor speed sensor, diesel engine model)

Compartment temperature is higher or lower than setting temperature.

• Auto A/C control module

• Air mix door actuator

• In-vehicle sensor, ambient sensor, evaporator sensor and sunload sensor

• In-vehicle sensor aspirator hose

Compartment temperature does not quickly respond to setting temperature.

• Air mix door actuator

• In-vehicle sensor, ambient sensor, evaporator sensor and sunload sensor

• In-vehicle sensor aspirator hose

Radiator fan does not rotate during A/C operation.

• Radiator fan motor

• Radiator fan relay