Contents Section: Automatic HVAC System All sections

HVAC System (Auto AC) (Diagnostics): Diagnosis Subaru Forester SG рестайлинг

Automatic HVAC System 1 illustration

INSPECTION

Before performing the diagnosis, check the following items which may cause problems in the A/C system.

A/C OR SELF-DIAGNOSIS SYSTEMS DO NOT OPERATE

TROUBLE SYMPTOM

  1. Set temperature is not indicated on the display, switch LEDs are faulty or switches do not operate.
  2. Self-diagnosis system does not operate. WIRING DIAGRAM

Scheme 1

Scheme 1
StepCheckYesNo
1 CHECK FUSE. Turn the ignition switch to OFF. Remove the fuse No. 2 from main fuse box. Check the condition of fuse.Is the fuse blown out?Replace the fuse.Go to step 2.
2 CHECK FUSE. Turn the ignition switch to OFF. Remove the fuse No. 17 from fuse & relay box. Check the condition of fuse.Is the fuse blown out?Replace the fuse.Go to step 3.
3 CHECK AUTO A/C CONTROL MODULE POWER CIRCUIT. Pull out the auto A/C control module connector. Measure the voltage between auto A/C control module connector terminal and chassis ground after turning the ignition switch OFF. Connector & terminal (i49) No. 4 (+) - Chassis ground (-)Is the voltage more than 10 V?Go to step 4.Repair the short circuit in harness for power supply line.
4 CHECK AUTO A/C CONTROL MODULE POWER CIRCUIT. Measure the voltage between auto A/C control module connector terminal and chassis ground after turning the ignition switch to the ON position. Connector & terminal (i49) No. 5 (+) - Chassis ground (-)Is the voltage more than 10 V?Go to step 5.Repair the short circuit in harness for power supply line.
5 CHECK AUTO A/C CONTROL MODULE GROUND CIRCUIT. Measure the resistance of harness between auto A/C control module and chassis ground after turning the ignition switch to the ON position. Connector & terminal (i49) No. 11 - Chassis groundIs the resistance less than 1 ohms?Go to step 6.Repair the short circuit in harness for ground line.
6 CHECK POOR CONTACT. Check poor contact of auto A/C control module connector.Is there poor contact in the connector?Repair the connector.Replace the auto A/C control module.

DIAGNOSTIC PROCEDURE CHART

GENERAL DIAGNOSTIC TABLE

SymptomProblem parts
A/C system fails to operate.Fuse Connector (Poor contact) Ground Auto A/C control module Blower fan motor Blower fan relay A/C relay Compressor (Magnet clutch) Evaporator sensor
Fuse is blown out.Fuse Connector (Poor contact)
Illumination cannot dim.Fuse Connector (Poor contact) Auto A/C control module
Blower fan does not rotate or fan speed cannot be controlled.Fuse 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
The 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
The 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 operation.Radiator fan motor Radiator fan relay

GENERAL DIAGNOSTIC