SAFETY PRECAUTIONS
| WARNING | Wear safety goggles and gloves when servicing the refrigeration system to prevent severe damage to eyes and hands. |
Because R-134a refrigerant is a hydro fluorocarbon (HFC) which contains hydrogen atoms in place of chlorine atoms, it will not cause damage to the ozone layer.
Ozone filters out harmful radiation from the sun. To assist in protecting the ozone layer, Mitsubishi Motors Corporation recommends an R-134a refrigerant recycling device.
Refrigerant R-134a is transparent and colorless in both the liquid and vapor state. Since it has a boiling point of - 29.8°C (- 21.64°F) at atmospheric pressure, it will be a vapor at all normal temperatures and pressures. The vapor is heavier than air, non-flammable, and non-explosive. The following precautions must be observed when handling R-134a.
| WARNING | Do not heat R-134a above 40°C (104.0°F) or it may catch fire and explode. |
R-134a evaporates so rapidly at normal atmospheric pressures and temperatures that it tends to freeze anything it contacts. For this reason, extreme care must be taken to prevent any liquid refrigerant from contacting the skin and especially the eyes. Always wear safety goggles when servicing the refrigeration part of the A/C system. Keep a bottle of sterile mineral oil handy when working on the refrigeration system.
- If any liquid refrigerant gets into your eyes, use a few drops of mineral oil to wash them out. R-134a is rapidly absorbed by the oil.
- Next, splash your eyes with plenty of cold water.
- Call your doctor immediately even if irritation has ceased.
| CAUTION | Keep R-134a containers upright when charging the system. |
In most instances, moderate heat is required to bring the pressure of the refrigerant in its container above the pressure of the system when charging or adding refrigerant.
A bucket or large pan of hot water not over 40°C (104.0°F) is all the heat required for this purpose. Do not heat the refrigerant container with a blow torch or any other means that would raise temperature and pressure above this temperature. Do not weld or steam-clean on or near the system components or refrigerant lines.
| WARNING | A leak detector for R-134a should be used to check for refrigerant gas leaks. |
| CAUTION | Do not allow liquid refrigerant to touch bright metal or it will be stained. |
When metering R-134a into the refrigeration system, keep the supply tank or cans in an upright position. If the refrigerant container is on its side or upside down, liquid refrigerant will enter the system and damage the compressor.
Refrigerant will tarnish bright metal and chrome surfaces, and in combination with moisture can severely corrode all metal surfaces.
CONDENSER FAN AND RADIATOR FAN CONTROL
The PCM judges the required revolution speed of radiator fan motor and condenser fan motor using the input signals transmitted from A/C switch, output shaft speed sensor and engine coolant temperature sensor. The PCM activates the fan control relays to drive the radiator fan motor and condenser fan motor.
When operating the A/C switch
- The air thermo sensor, which senses the temperature of the air flowing out of the evaporator, deactivates the compressor at 3°C (37.4°F) or below.
- The dual pressure switch turns OFF when the refrigerant pressure becomes excessively high or low, thus protecting the compressor circuit (See «A/C COMPRESSOR CLUTCH RELAY ON CONDITIONS REFERENCE CHART»(ref-373567-S13741506312010101300000) below).
- When the air thermo sensor is activated, and the ignition switch, blower switch, and A/C switch are ON, the A/C compressor clutch relay is energized.
When operating the mode selection dial
- The A/C will work when the mode selection dial is set to the "Defroster" or "Defroster/foot" position, or the temperature control dial is set to the "MAX A/C" position. In other dial positions, when the A/C switch is turned on, the A/C will work.
A/C Compressor Clutch Relay ON Conditions
| Ignition switch (IG2) | ON | NOTE: A/C compressor clutch relay is de-energized when any one switch, sensor or control unit shown on the left turns off. NOTE: The components marked by * communicate with the PCM. If the air thermo sensor detects a temperature of 3°C (37.4°F), the A/C-ECU will turn off the A/C compressor clutch relay. | |
|---|---|---|---|
| Blower switch | ON | ||
| A/C switch, mode selection dial defroster, defroster/foot position or temperature control MAX A/C | ON | ||
| Air thermo sensor | * | ||
| Pressure detected by A/C pressure sensor | 2.94 MPa (427 psi) or less (If the refrigerant pressure exceeds 2.94 MPa (427 psi), A/C compressor clutch relay is not ON condition until the refrigerant pressure has been measured up to 2.35 MP (341 psi) or less.) | ON | |
| 0.19 MPa (27 psi) or more (If the refrigerant pressure falls short of 0.19 MPa (27 psi), A/C compressor clutch relay is not ON condition until the refrigerant pressure has been measured up to 0.22 MPa (32 psi) or more.) | |||
| A/C compressor clutch relay driving transistor (within powertrain control module) | ON | ||
| NOTE |
|---|
| A/C compressor clutch relay is de-energized when any one switch, sensor or control unit shown on the left turns off. |
| NOTE |
|---|
| The components marked by * communicate with the PCM. If the air thermo sensor detects a temperature of 3°C (37.4°F), the A/C-ECU will turn off the A/C compressor clutch relay. |
A/C COMPRESSOR CLUTCH RELAY ON CONDITIONS
HOW TO READ DATA LIST
Required Special Tools
- MB991958: Scan Tool (M.U.T.-III Sub Assembly) MB991824: Vehicle Communication Interface (V. C. I.) MB991827: M.U.T.-III USB Cable MB991910: M.U.T.-III Main Harness A (Vehicles with CAN communication system)
| CAUTION | To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958. |
- Connect the scan tool MB991958 to the data link connector.
- Turn the ignition switch to the "ON" position.
- Select "Interactive Diagnosis" from the start-up screen.
- Select "System Select."
- Choose "AUTO A/C" from the "BODY" tab.
- Select "MITSUBISHI."
- Select "Data List."
- Choose an appropriate item and select the "OK" button.
DATA LIST REFERENCE TABLE
| Scan tool (M.U.T.-III) display | Item No. | Inspection item | Inspection requirement | Normal value |
|---|---|---|---|---|
| Inside temperature sensor | 01 | Interior temperature sensor | Ignition switch: ON | Inside air temperature and temperature displayed on the scan tool are identical. |
| Photo sensor (1) | 06 | Photo sensor | ||
| (1) shows that it is displayed but not used. | ||||
| (1) | Shows that it is displayed but not used. |
DATA LIST REFERENCE
Scheme 11
| Terminal No. | Check item | Checking requirements | Normal condition |
|---|---|---|---|
| 1 | Air mixing damper control motor | When the air mix damper is moved to the MAX. COOL position. | 10 V |
| When the air mix damper is moved to the MAX. HOT position. | 0.5 V | ||
| 2 | Air mixing damper control motor | When the air mix damper is moved to the MAX. COOL position. | 0.5 V |
| When the air mix damper is moved to the MAX. HOT position. | 10 V | ||
| 3 | Back-up power supply | Always | Battery positive voltage |
| 4 | Mode selection damper control motor (DEF) | When the damper is moved to the FACE position. | 0.5 V |
| When the damper is moved to the DEF position. | 10 V | ||
| 5 | Outside/inside air selection damper control motor (outside) | When the damper is moved to the inside air recirculation position. | 0.5 V |
| When the damper is moved to the outside air induction position. | 1 V or less (when the motor is stopped) | ||
| 6 | Outside/inside air selection damper control motor (inside) | When the damper is moved to the inside air recirculation position. | 1 V or less (when the motor is stopped) |
| When the damper is moved to the outside air induction position. | 0.5 V | ||
| 8 | Rear defogger relay | Ignition switch: ON | Battery positive voltage |
| 9 | Front blower relay | Ignition switch: ON | Battery positive voltage |
| 10 | A/C compressor relay | A/C compressor relay: ON | Battery positive voltage |
| 11 | Mode selection damper control motor (FACE) | When the damper is moved to the FACE position. | 10 V |
| When the damper is moved to the DEF position. | 0.5 V | ||
| 12 | A/C pressure sensor | Ignition switch: ON | 5 V |
| 16 | Potentiometer power supply | Ignition switch: ON | 5 V |
| 17 | Power transistor (BASE) | When the blower speed selection dial shows Maximum air volume. | 1 V or less |
| 18 | Power transistor (COLLECTOR) | When the blower speed selection dial shows Maximum air volume. | 12.1 V |
| 20 | Sensors and potentiometers ground | Always | 1 V or less |
| 21 | Mode selection damper control motor potentiometer input | When the damper is moved to the FACE position. | 4 V |
| 22 | Interior temperature sensor | Ignition switch: ON | 5 V |
| 23 | Ambient temperature sensor input | When sensor temperature is 25°C (77°F) [4 kohms] | 1.9 V |
| 24 | Air thermo sensor input | When sensor temperature is 25°C (77°F) [1.5 kohms] | 2.2 V |
| 26 | A/C pressure sensor | At 2.6 MPa | 3.9 V |
| 27 | Ground | Always | 1 V or less |
| 28 | Power supply to the ignition switch (IG2) | Ignition switch: ON | Battery positive voltage |
| 29 | Air mixing damper control motor potentiometer input | When the damper door is moved to the MAX. HOT position. | 1.4 V |
| 30 | Illumination ground | Always | 1 V or less |
| 31 | ILL power supply | Lighting switch: ON | Battery positive voltage |
| 34 | A/C pressure sensor ground | Always | 1 V or less |
| 36 | Power supply to the ignition switch (ACC) | Ignition switch: ON | Battery positive voltage |
CONNECTOR TERMINAL REFERENCE
INTERIOR TEMPERATURE SENSOR CHECK
When the resistance between the sensor terminals is measured under two or more temperature conditions, the resistance should approximately satisfy the illustrated values.
Scheme 12
Note. The temperature conditions when checking should not exceed the range shown in the illustration.
