Pre-Inspection
CAUTION:1. Never connect the battery in reverse polarity.
- The Auto A/C control module will be destroyed instantly.
2. Do not disconnect the battery terminals while the engine is running.
- A large counter electro motive force will be generated in the alternator, and this voltage may damage electronic parts such as A/C control module.
3. Before disconnecting the connectors of each sensor and the A/C control module, be sure to turn off the ignition switch.
- Otherwise, the Auto A/C control module may be damaged.
4 Every Auto A/C-related part is a precision part. Do not drop them.
5. Airbag system wiring harness is routed near the A/C control panel (A/C control module) and junction box.
- All Airbag system wiring harness and connectors are colored yellow. Do not use electrical test equipment on these circuits.
- Be careful not to damage Airbag system wiring harness when servicing the A/C control panel (A/C control module) and junction box.
INSPECTION
Before performing diagnosis, check the following items which might affect engine problems.
1. BATTERY
1. Measure battery voltage and specific gravity of electrolyte.
Standard voltage: 12 V
Specific gravity: Above 1.260
2. Check the condition of the fuses for A/C, heater and other fuses.
3. Check the condition of the harnesses and harness connectors connection.
2. ASPIRATOR HOSE
1. Make sure that the aspirator hose is securely connected to the heater unit by inserting a hand from the driver's compartment and secure as necessary.
2. Turn ignition switch to ON.
3. Push "DEF" switch and then blower fan switch to turn the blower fan to maximum speed.
4. Firmly hold a thin thread (b) in front of the in-vehicle sensor suction port (a) for the auto A/C control unit and check that the thread moves towards the port indicating that air is being sucked into the port.
NOTE:
- Ensure the thread does not get sucked into the port.
- Hold the thread approximately 5 mm (0.02 in) away from the port when the suction force is not very strong.
5. If the thread does not move at all, remove the auto A/C control unit and check for improper connection of the aspirator hose (a) and auto A/C control unit and secure as necessary.
3. REFRIGERANT LINE
Check contact for refrigerant line (A).
4. CONTROL LINKAGE
1. Check state of mode door control rod and linkage.
2. Check state of air mix door control rod and linkage.
3. Check state of intake door control rod and linkage.
5. CONTROL SWITCHES
Start and warm up engine completely.
1. Inspection using switches.
2. Compressor operation inspection
3. Illumination control inspection