Automatic Heating & A/c: Diagnosis Daewoo Nubira II

GENERAL DIAGNOSTICS

The V5 variable displacement compressor combines with thermal expansion valve to form a largely self regulating system. In high pressure refrigerant line, there is a pressure sensor rather than a traditional high or low pressure cut-off switch or pressure cycling switch. The compressor clutch is controlled by Powertrain Control Module (PCM)/Engine Control Module (ECM), which monitors data from various engine systems. The PCM/ECM will disengage compressor clutch if following conditions are detected

1. The air conditioning is OFF.
2. The throttle is in wide-open position.
3. High engine coolant temperature.
4. High engine RPM.
5. Low refrigerant pressure.
6. High refrigerant pressure.

The compressor clutch will remain disengaged until normal operation is established.

SELF-DIAGNOSTIC CIRCUIT CHECK

The Daewoo Fully Automatic Temperature Controller (FATC) contains a self-diagnostic function to aid in finding any problem with system. To enter diagnostic mode, perform following procedures

1. Turn ignition switch ON.
2. Set temperature control to 79°F (26°C).
3. Within 3 seconds, push AUTO and OFF switches simultaneously, more than 3 times.
4. Count number of times temperature indicator screen blinks.
5. If there are no error codes set, screen will not blink. When controller indicates an error code, proceed to table for that code.
6. Push OFF switch to return controller to its normal functions.

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SYSTEM TESTS (DTC TESTS)

DTC INDEX

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