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.
- Should any liquid refrigerant get 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 ECM 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.
COMPRESSOR CONTROL
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 1°C (33.8°F) or below.
- A/C-ECU detect refrigerant pressure by A/C pressure sensor and turns OFF when the refrigerant pressure becomes excessively high or low, thus protecting the compressor circuit (See «A/C COMPRESSOR CLUTCH RELAY ON CONDITIONS»(ref-593021-S13699684212014011300000) ).
- 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 ECU. If the air thermo sensor detects a temperature of 1°C (33.8°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 (427psi) or less (If the refrigerant pressure exceeds 2.94 MPa (427psi), A/C compressor clutch relay is not ON condition until the refrigerant pressure has been measured up to 2.35 MPa (341psi) a or less.) | ON | |
| 0.19 MPa (27psi) or more (If the refrigerant pressure falls short of 0.19 MPa (27psi), A/C compressor clutch relay is not ON condition until the refrigerant pressure has been measured up to 0.22 MPa (32psi) 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 ECU. If the air thermo sensor detects a temperature of 1°C (33.8°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." Select "AUTO A/C" from "System List," and press the "OK" button.
- Select "Data List."
- Choose an appropriate item and select the "OK" button.
CHECK OF FREEZE FRAME DATA
The freeze frame data can be checked by using the scan tool. HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
When detecting fault and storing the DTC, the ECU connected to CAN bus line obtains the data before the determination of the DTC and the data when the DTC is determined, and then stores the ECU status of that time. By analyzing the data from scan tool, the troubleshooting can be performed more efficiently. The displayed items are as shown in the table below.
Display item list
| Item No. | Item name | Data item | Unit |
|---|---|---|---|
| 01 | Odometer | Total driving distance after the diagnostic trouble code is generated | Mile (1) |
| 02 | Ignition cycle | Number of times the ignition switch is turned "ON" or "LOCK (OFF)" after the past failure transition | Number of counts is displayed. |
| 04 | Current trouble accumulative time | Cumulative time for current malfunction of diagnostic trouble code | Min |
| (1) If a failure occurs to both the ABS-ECU and ETACS-ECU, 0000 km or FFFF mile is displayed to the scan tool MB991958. | |||
| (1) | If a failure occurs to both the ABS-ECU and ETACS-ECU, 0000 km or FFFF mile is displayed to the scan tool MB991958. |
FREEZE FRAME DATA
DATA LIST REFERENCE TABLE
| Scan tool display | Item No. | The display contents under normal conditions |
|---|---|---|
| Engine speed | 17 | Displays correct engine speed. |
| Ambient temperature sensor | 19 | Ambient temperature is the same as scan tool displayed temperature |
| Air thermo sensor | 20 | Evaporator outlet temperature is the same as scan tool displayed temperature. |
| Interior temperature sensor | 21 | Interior temperature is the same as scan tool displayed temperature |
| Temperature setting | 23 | Displays air conditioning set temperature. |
| ETC sensor | 24 | Engine coolant temperature is the same as scan tool displayed temperature. |
| Vehicle speed | 26 | Displays vehicle speed. |
| A/C Compressor drive request | 27 | Compressor ON |
| Compressor OFF | ||
| Air conditioning switch | 28 | Air conditioning switch ON |
| Air conditioning switch OFF | ||
| Refrigerant leak | 29 | Normal |
| Idle up request | 34 | Displays idle-up request signal. |
| Rear heater SW light (1) | 35 | |
| PTC heater 1 (1) | 36 | |
| PTC heater 2 (1) | 37 | |
| PTC heater 3 (1) | 38 | |
| In/out select damp poten (target) | 45 | Displays outside/inside air selection damper target position. |
| In/out select damp potentiometer | 46 | Displays outside/inside air selection damper position. |
| Air outlet c/o potentiometer | 55 | Displays air outlet changeover damper position. |
| Air outlet c/o potentio. (Target) | 56 | Displays air outlet changeover damper target position. |
| Low pressure judgment | 57 | Normal |
| Rear defogger switch | 60 | ON Rear window defogger switch ON |
| OFF Rear window defogger switch OFF | ||
| Pressure sensor | 61 | Displays refrigerant pressure. |
| Air mix potentiometer | 63 | Displays the air mix damper position. |
| Photo sensor (1) | 67 | |
| Front blower fan | 68 | Displays blower motor condition. |
| Front blower fan (Target) | 69 | Displays blower motor target value. |
| Refrigerant pressure | 73 | Displays refrigerant pressure status. |
| Condenser fan | 74 | Displays condenser fan running condition. |
| Temp. set dial position | 76 | Displays the set temperature output value on the control panel. |
| A/C Panel type | 77 | Dial/Auto/RHD |
| Fan set dial position | 78 | Displays the air volume output value on the control panel. |
| Air outlet c/o set dial position | 79 | Displays output value to the air outlet changeover dial on the control panel. |
| Fan set dial operation flag | 80 | ON when the air volume adjusting dial is operated |
| A/C SW operation flag | 81 | ON when the air conditioning switch is operated |
| Temp. set dial operation flag | 82 | ON when the air conditioning switch is operated |
| Defogger flag (1) | 83 | |
| In/out air c/o SW operation flag (1) | 84 | |
| Rear defogger SW operation flag (1) | 87 | |
| Rear defogger SW light | 88 | Displays rear window switch indicator status. |
| A/C SW light | 89 | Displays air conditioning switch indicator status. |
| In/out air c/o SW light | 90 | Displays the status of the inside air/outside air changeover switch indicator. |
| A/C Compressor drive flag | 91 | ON when the compressor is activated. |
| Wiper operation flag | 92 | ON when the wiper is operated. |
| Ignition position information | 93 | Ignition switch position status |
| Power source voltage | 94 | Displays power supply voltage. |
| IOD fuse equipment flag | 95 | IOD fuse status |
| A/T lock up open request | 96 | |
| System operation time | 100 | |
| Compressor use times | 101 | |
| Rear defogger use times | 102 | |
| In/out air c/o poten drive time | 103 | |
| Air outlet c/o poten drive time | 104 | |
| Air mix potentiometer drive time | 105 | |
| Hot state time (Interior TEMP.) | 106 | |
| Cold state time (Interior TEMP.) | 107 | |
| Hot state time (Ambient TEMP.) | 108 | |
| Cold state time (Ambient TEMP.) | 109 | |
| Maximum ambient temperature | 110 | |
| Minimum ambient temperature | 111 | |
| Maximum Engine coolant TEMP. | 112 | |
| Engine high speed time | 113 | |
| Maximum Engine speed | 114 | |
| High pressure drive time | 115 | |
| High pressure cut times | 116 | |
| Maximum pressure (kPa) | 117 | |
| A/C use rate | 118 | |
| Compressor operation rate | 119 | |
| Eco operation rate | 120 | |
| Recirc use rate | 121 | |
| A/C operation times | 122 | |
| In/out air c/o operation times | 123 | |
| Mode dial operation times | 124 | |
| Blower fan dial operation times | 125 | |
| TEMP. set dial operation times | 126 | |
| FACE mode use rate | 127 | |
| B/L mode use rate | 128 | |
| FOOT mode use rate | 129 | |
| D/F mode use rate | 130 | |
| DEF mode use rate | 131 | |
| Fan OFF use rate | 132 | |
| Fan 1-2step use rate | 133 | |
| Fan 3-4step use rate | 134 | |
| Fan 5-6step use rate | 135 | |
| Fan 7-8step use rate | 136 | |
| Temp 1-7 step use rate | 137 | |
| Temp 8-10step use rate | 138 | |
| Temp 11-13 step use rate | 139 | |
| Temp 17-19step use rate | 140 | |
| Temp 20-22step use rate | 141 | |
| Temp 23-29step use rate | 142 | |
| PTC heater1 use times (1) | 143 | |
| PTC heater2 use times (1) | 144 | |
| PTC heater3 use times (1) | 145 | |
| Fan LO driving time | 146 | |
| Fan M1 driving time | 147 | |
| Fan M2 driving time | 148 | |
| Fan HI driving time | 149 | |
| Rear PTC heater counter (1) | 150 | |
| (1) shows that it is displayed but not used. | ||
| (1) | Shows that it is displayed but not used. |
DATA LIST REFERENCE
INTERIOR TEMPERATURE SENSOR CHECK
Check to see that the resistance see scheme 10is almost satisfied when measuring the resistance between the terminals under two or more different temperature conditions.
