Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual - part 608
AC(diag)-37
Diagnostics with Phenomenon
HVAC SYSTEM (AUTO A/C) (DIAGNOSTICS)
9. Diagnostics with Phenomenon
A: INSPECTION
Symptoms
Faulty 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
• ECM
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
• Power transistor
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
Compartment 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
Compartment 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
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 opera-
tion.
• Radiator fan motor
• Radiator fan relay
• ECM