Precautions for Working with HFC-134a (R-134a)
| WARNING | CFC-12 (R-12) refrigerant and HFC-134a (R-134a) refrigerant are not compatible. If the refrigerants are mixed compressor failure is likely to occur. Refer to PRECAUTIONS: CONTAMINATED REFRIGERANT . To determine the purity of HFC-134a (R-134a) in the vehicle and recovery tank, use Refrigerant Recovery/Recycling Recharging equipment and Refrigerant Identifier. Use only specified oil for the HFC-134a (R-134a) A/C system and HFC-134a (R-134a) components. If oil other than that specified is used, compressor failure is likely to occur. The specified HFC-134a (R-134a) oil rapidly absorbs moisture from the atmosphere. The following handling precautions must be observed: When removing refrigerant components from a vehicle, immediately cap (seal) the component to minimize the entry of moisture from the atmosphere. When installing refrigerant components to a vehicle, do not remove the caps (unseal) until just before connecting the components. Connect all refrigerant loop components as quickly as possible to minimize the entry of moisture into system. Only use the specified oil from a sealed container. Immediately reseal containers of oil. Without proper sealing, oil will become moisture saturated and should not be used. Avoid breathing A/C refrigerant and oil vapor or mist. Exposure may irritate eyes, nose and throat. Remove HFC-134a (R-134a) from the A/C system using certified service equipment meeting requirements of SAE J2210 [HFC-134a (R-134a) recycling equipment], or J2209 [HFC-134a (R-134a) recycling equipment], If accidental system discharge occurs, ventilate work area before resuming service. Additional health and safety information may be obtained from refrigerant and oil manufacturers. Do not allow A/C oil to come in contact with styrofoam parts. Damage may result. |
CONTAMINATED REFRIGERANT
If a refrigerant other than pure HFC-134a (R-134a) is identified in a vehicle, your options are
- Explain to the customer that environmental regulations prohibit the release of contaminated refrigerant into the atmosphere.
- Explain that recovery of the contaminated refrigerant could damage your service equipment and refrigerant supply.
- Suggest the customer return the vehicle to the location of previous service where the contamination may have occurred.
- If you choose to perform the repair, recover the refrigerant using only dedicated equipment and containers. Do not recover contaminated refrigerant into your existing service equipment. If your facility does not have dedicated recovery equipment, you may contact a local refrigerant product retailer for available service. This refrigerant must be disposed of in accordance with all federal and local regulations. In addition, replacement of all refrigerant system components on the vehicle is recommended.
- If the vehicle is within the warranty period, the air conditioner warranty is void. Please contact SUZUKI Customer Affairs for further assistance.
MANIFOLD GAUGE SET
Be certain that the gauge face indicates R-134a or 134a. Make sure the gauge set has 1/2"-16 ACME threaded connections for service hoses. Confirm the set has been used only with refrigerant HFC-134a (R-134a) along with specified oil.
Scheme 145
SERVICE HOSES
Be certain that the service hoses display the markings described (colored hose with black stripe). All hoses must include positive shut- off devices (either manual or automatic) near the end of the hoses opposite the manifold gauge.
Scheme 146
SERVICE COUPLERS
Never attempt to connect HFC-134a (R-134a) service couplers to a CFC-12 (R-12) A/C system. The HFC-134a (R-134a) couplers will not properly connect to the CFC-12 (R-12) system. However, if an improper connection is attempted, discharging and contamination may occur.
Scheme 147
| Shut-off valve rotation | A/C service valve |
|---|---|
| Clockwise | Open |
| Counterclockwise | Close |
A/C SERVICE VALVE CONDITION CHART
WORK FLOW
| Step | Action | YES | NO |
|---|---|---|---|
| 1 | LISTEN TO CUSTOMER COMPLAINT Listen to customer complaint. Get detailed information about the conditions and environment when the symptom occurs. | GO TO 2 | |
| 2 | CHECK FOR SERVICE BULLETINS Check for any service bulletins. | GO TO 3. | |
| 3 | VERIFY THE SYMPTOM WITH OPERATIONAL CHECK Verify the symptom with operational check. Refer to HEATER & AIR CONDITIONING CONTROL SYSTEM: OPERATIONAL CHECK . Can a symptom be duplicated? | Go to trouble diagnosis. Refer to SYMPTOM MATRIX CHART . | System OK. |
DIAGNOSIS PROCEDURE
TEMPERATURE CONTROL DIAL (TEMPERATURE CONTROL)
Increases or decreases the set temperature.
RECIRCULATION SWITCH
- When REC switch is ON, REC switch indicator turns ON, and air inlet is set to REC.
- When REC switch is turned OFF, or when compressor is turned from ON to OFF, REC switch is automatically turned OFF. REC mode can be re-entered by pressing REC switch again.
- REC switch is not operated when DEF switch is turned ON, or at the D/F or FOOT position.
REAR WINDOW DEFOGGER SWITCH (IF EQUIPPED)
When switch is ON, rear window is defogged.
OFF SWITCH (BLOWER SPEED SET TO 0)
The compressor and blower are OFF.
A/C SWITCH (IF EQUIPPED)
The compressor is ON or OFF.
(Pressing the A/C switch will turn off the A/C switch and compressor.)
MODE DIAL
Controls the air discharge outlets.
FRONT BLOWER CONTROL DIAL
Manually controls the four blower speeds.
Scheme 148
When the A/C switch is pressed, or the mode dial is turned to the DEF or D/F position, the front air control outputs a compressor ON signal to BCM.
The BCM then sends a compressor ON signal to ECM, via CAN communication line.
ECM judges whether compressor can be turned ON, based on each sensor status (refrigerant pressure sensor signal, throttle angle sensor, etc.). If it judges compressor can be turned ON, it sends compressor ON signal to IPDM E/R, via CAN communication line.
Upon receipt of compressor ON signal from ECM, IPDM E/R turns air conditioner relay ON to operate compressor.
Discharge Air Flow Table
MODE DOOR POSITION CHART Mode door position Air outlet/distribution Vent Foot Defroster 95% 5% - 60% 40% - 20% 55% 25% 15% 50% 35% 7% 15% 78% Airflow always present at driver and passenger side demisters
Scheme 149
Scheme 150
Scheme 151
Scheme 152
Scheme 153
Scheme 154
Scheme 155
Refrigerant Cycle
Refer to REFRIGERATION SYSTEM: REFRIGERANT CYCLE
CONTROL SYSTEM
The control system consists of input sensors, switches, the front air control (microcomputer) and outputs.
The relationship of these components is shown in the figure below
Scheme 156
Scheme 157
Scheme 158
CHECKING BLOWER
- Turn blower control dial clockwise. Blower should operate on low speed.
- Turn the blower control dial again, and continue checking each blower speed until all speeds are checked.
- Leave blower on speed 4.
If NG, go to trouble diagnosis procedure for BLOWER MOTOR CIRCUIT CHECK .
If OK, continue with next check.
CHECKING DISCHARGE AIR
- Turn the mode switch to each position.
- Confirm that discharge air comes out according to the air distribution table. Refer to «DISCHARGE AIR FLOW TABLE»(ref-375752-S15526764642010102800000) .
Mode door position is checked in the next step.
If NG, go to trouble diagnosis procedure for MODE DOOR MOTOR CIRCUIT CHECK .
If OK, continue with next check.
Note. Confirm that the A/C compressor clutch is engaged (sound or visual inspection) and intake door position is at fresh when the DEF or D/F is selected.
CHECKING RECIRCULATION
- Press recirculation switch one time. Recirculation indicator should illuminate.
- Press recirculation switch one more time. Recirculation indicator should go off.
- Listen for intake door position change (blower sound should change slightly).
If NG, go to trouble diagnosis procedure for INTAKE DOOR MOTOR CIRCUIT CHECK .
If OK, continue with next check.
Note. Confirm that the compressor clutch is engaged (sound or visual inspection) and intake door position is at fresh when the DEF or D/F is selected.
CHECKING TEMPERATURE DECREASE
- Rotate temperature control dial counterclockwise.
- Check for cold air at appropriate discharge air outlets.
If NG, listen for sound of air mix door motor operation if OK, go to trouble diagnosis procedure for INSUFFICIENT COOLING . If air mix door motor appears to be malfunctioning, go to AIR MIX DOOR MOTOR CIRCUIT CHECK .
If OK, continue with next check.
CHECKING TEMPERATURE INCREASE
- Rotate temperature control dial clockwise.
- Check for hot air at appropriate discharge air outlets.
If NG, listen for sound of air mix door motor operation. If OK, go to trouble diagnosis procedure for INSUFFICIENT HEATING . If air mix door motor (front) appears to be malfunctioning, go to AIR MIX DOOR MOTOR CIRCUIT CHECK .
If OK, continue with next check.
CHECK A/C SWITCH (IF EQUIPPED)
- Press A/C switch with the blower switch ON.
- A/C switch indicator will turn ON. Confirm that the compressor clutch engages (sound or visual inspection).
If NG, go to trouble diagnosis procedure for MAGNET CLUTCH CIRCUIT CHECK .
If OK, continue with next check.
SDT Function (BCM - COMMON ITEM)
Refer to SDT FUNCTION (BCM - COMMON ITEM) .
SDT Function (BCM - AIR CONDITIONER)
Refer to SDT FUNCTION (BCM - AIR CONDITIONER) .
Front Air Control
The front air control has a built-in microcomputer which processes information sent from various sensors needed for air conditioner operation. The air mix door motor, mode door motor, intake door motor, defroster door motor, blower motor and compressor are then controlled.
Scheme 159
The front air control is unitized with control mechanisms. When the various switches and temperature dials are operated, data is input to the front air control.
Potentio Temperature Control (PTC)
The PTC is built into the front air control. It can be set from cold to hot or any intermediate position by rotating the temperature dial.
Scheme 160
Front Air Control Component Function Check
SYMPTOM: A/C system does not come on. (if equipped)
TERMINALS AND REFERENCE VALUES FOR FRONT AIR CONTROL
FRONT AIR CONTROL TERMINAL REFERENCE Terminal No. Wire color Item Ignition switch Condition Voltage (V) (Approx.) 1 BR Mode door motor CW ON Clockwise rotation Battery voltage 2 W Air mix door motor CW ON Clockwise rotation Battery voltage 3 GR Air mix door motor CCW ON Counterclockwise rotation Battery voltage 4 Y Intake door motor CW ON Clockwise rotation Battery voltage 5 O Intake door motor CCW ON Counterclockwise rotation Battery voltage 6 W/G Power supply for IGN ON - Battery voltage 8 G Illumination + ON Park lamps ON Battery voltage 9 BR Illumination - - Park lamps ON 10 W Compressor ON signal ON A/C switch OFF 5V ON A/C switch ON 0V 11 - - - - - 12 L Intake sensor ON - 0 - 5V 13 V Sensor ground ON - 0 - 5V 14 R Mode door motor CCW ON Counterclockwise rotation Battery voltage 18 BR Front blower monitor ON Front blower motor OFF Battery voltage Front blower motor ON 0V 19 R/Y Power supply for BAT - - Battery voltage 20 B Ground - - 0V 21 V Mode door motor feedback ON - 0 - 5V 22 SB Air mix door motor feedback ON - 0 - 5V 23 G Power supply for mode door motor and air mix door motor PBR ON - 5V 25 - - - - - 26 P Ground for mode door motor and air mix door motor PBR ON - 0V
Scheme 161
Component Parts
Mode door control system components are
- Front air control
- Mode door motor
- PBR (built into mode door motor)
- Intake sensor
Mode Door Motor
The mode door motor is attached to the heater and cooling unit assembly. It rotates so that air is discharged from the outlet as indicated by the front air control. Motor rotation is conveyed to a link which activates the mode door.
Scheme 162
Mode Door Motor Component Function Check
SYMPTOM
- Air outlet does not change.
- Mode door motor does not operate normally.
Air mix door control system components are
- Front air control
- Air mix door motor
- PBR (built into air mix door motor)
- Intake sensor
Air Mix Door Motor
The air mix door motor is attached to the heater and cooling unit assembly. This motor rotates so that the air mix door is opened or closed to a position set by the front air control. Motor rotation is then conveyed through a shaft and the air mix door position is then fed back to the front air control by the PBR built into the air mix door motor.
Scheme 163
Intake door control system components are
- Front air control
- Intake door motor
- Intake sensor
Intake door motor
The intake door motor is attached to the intake unit. It rotates so that air is drawn from inlets set by the front air control. Motor rotation is conveyed to a lever which activates the intake door.
Scheme 164
Intake Door Motor Component Function Check
SYMPTOM
- Intake door does not change.
- Intake door motor does not operate normally.
Blower speed control system components are
- Front air control
- Front blower motor resistor
- Front blower motor
- Front blower relay
- Front blower switch
Scheme 165
Blower Motor Resistor
The front blower motor resistor (1) is located on the heater and cooling unit assembly. The front blower motor resistor grounds the front blower motor through a series of 1, 2, or 3 resistors, depending upon speed selected. For high speed operation the front blower motor resistor is circumvented and the front blower motor grounds directly.
Scheme 166
Front Blower Motor Relay
Check continuity between terminals by supplying 12 volts and ground to coil side terminals of relay.
Front Blower Motor
Confirm smooth rotation of the blower motor.
Scheme 167
- Ensure that there are no foreign particles inside the blower unit.
- Apply 12 volts to terminal 2 and ground to terminal 1 and verify that the motor operates freely and quietly.
Front Blower Switch
Check continuity between terminals at each switch position.
Scheme 168
Front Blower Motor Resistor
Check continuity between terminals. There will be resistance, but there should not be an open or short between any two terminals.
Scheme 169
Low Temperature Protection Control
The front air control will turn the compressor ON or OFF as determined by a signal detected by the intake sensor.
When intake air temperature is higher than 3.5 °C (38.3 °F), the compressor turns ON. The compressor turns OFF when intake air temperature is lower than 2.5 °C (36.5 °F).
Magnet Clutch Component Function Check
SYMPTOM: Magnet clutch does not engage.
Intake Sensor
The intake sensor is located on top of the heater and cooling unit assembly next to the A/C evaporator cover. It converts temperature of air after it passes through the evaporator into a resistance value which is then input to the front air control.
Scheme 170
After disconnecting intake sensor connector, measure resistance between terminals 1 and 2 at sensor harness side, using the table below.
Scheme 171
| Temperature °C (°F) | Resistance kohms |
|---|---|
| 15 (5) | 209.0 |
| 10 (14) | 160.0 |
| 5 (23) | 123.0 |
| 0 (32) | 95.8 |
| 5 (41) | 74.9 |
| 10 (50) | 58.9 |
| 15 (59) | 46.7 |
| 20 (68) | 37.3 |
| 25 (77) | 30.0 |
| 30 (86) | 24.2 |
| 35 (95) | 19.7 |
| 40 (104) | 16.1 |
| 45 (113) | 13.2 |
TEMPERATURE RESISTANCE CHART
If NG, replace intake sensor. Refer to INTAKE SENSOR: REMOVAL AND INSTALLATION
Component Function Check
SYMPTOM: Insufficient cooling
Recirculating-to-discharge Air Temperature Table
| Inside air (Recirculating air) at blower assembly inlet | Discharge air temperature at center ventilator °C (°F) | |
|---|---|---|
| Relative humidity % | Air temperature °C (°F) | |
| 50 - 60 | 20 (68) | 5.3 - 6.5 (42 - 44) |
| 25 (77) | 9.7 - 11.5 (49 - 53) | |
| 30 (86) | 13.8 - 16.3 (57 - 61) | |
| 35 (95) | 18.0 - 21.2 (64 - 70) | |
| 40 (104) | 22.2 - 25.7 (72 - 78) | |
| 60 - 70 | 20 (68) | 6.5 - 7.7 (44 - 46) |
| 25 (77) | 11.5 - 13.3 (53 - 56) | |
| 30 (86) | 16.3 - 18.8 (61 - 66) | |
| 35 (95) | 21.2 - 24.0 (70 - 75) | |
| 40 (104) | 25.7 - 29.2 (78 - 85) | |
RECIRCULATING-TO-DISCHARGE AIR TEMPERATURE CHART
Ambient Air Temperature-to-operating Pressure Table
Ambient air
| Relative humidity % | Air temperature °C (°F) | High-pressure (Discharge side) kPa (kg/cm 2 , psi) | Low-pressure (Suction side) kPa (kg/cm 2 , psi) |
|---|---|---|---|
| 50 - 70 | 20 (68) | 680 - 840 (6.94 - 8.57, 98.6 - 121.8) | 160 - 198 (1.63 - 2.02, 23.2 - 28.7) |
| 25 (77) | 800 - 985 (8.16 - 10.05, 116.0 - 142.8) | 198 - 245 (2.02 - 2.50, 28.7 - 35.5) | |
| 30 (86) | 940 - 1,150 (9.59 - 11.73, 136.3 - 166.8) | 225 - 278 (2.30 - 2.84, 32.6 - 40.3) | |
| 35 (95) | 1,160 - 1,410 (11.83 - 14.38, 168.2 - 204.5) | 273 - 335 (2.78 - 3.42, 39.6 - 48.6) | |
| 40 (104) | 1,325 - 1,620 (13.52 - 16.52, 192.1 - 234.9) | 325 - 398 (3.32 - 4.06, 47.1 - 57.7) |
AMBIENT AIR TEMPERATURE-TO-OPERATING PRESSURE CHART
Both High- and Low-pressure Sides are Too High
GAUGE INDICATION CHART Gauge indication Refrigerant cycle Probable cause Corrective action [A] Both high- and low-pressure sides are too high. Pressure is reduced soon after water is splashed on condenser. Excessive refrigerant charge in refrigeration cycle Reduce refrigerant until specified pressure is obtained. Air suction by cooling fan is insufficient. Insufficient condenser cooling performance ↓ Condenser fins are clogged. Improper fan rotation of cooling fan Clean condenser. Check and repair cooling fan if necessary. Low-pressure pipe is not cold. When compressor is stopped high-pressure value quickly drops by approximately 196 kPa (2 kg/cm 2 , 28 psi). It then decreases gradually thereafter. Poor heat exchange in condenser (After compressor operation stops, high-pressure decreases too slowly.) ↓ Air in refrigeration cycle Evacuate and recharge system. Engine tends to overheat. Engine cooling systems malfunction. Check and repair engine cooling system. An area of the low-pressure pipe is colder than areas near the evaporator outlet. Plates are sometimes covered with frost. Excessive liquid refrigerant on low-pressure side Excessive refrigerant discharge flow Expansion valve is open a little compared with the specification. ↓ Improper expansion valve adjustment Replace expansion valve
Scheme 172
High-pressure Side is Too High and Low-pressure Side is Too Low
GAUGE INDICATION CHART Gauge indication Refrigerant cycle Probable cause Corrective action [B] High-pressure side is too high and low-pressure side is too low. Upper side of condenser and high-pressure side are hot, however, liquid tank is not so hot. High-pressure tube or parts located between compressor and condenser are clogged or crushed. Check and repair or replace malfunctioning parts. Check oil for contamination
Scheme 173
High-pressure Side is Too Low and Low-pressure Side is Too High
GAUGE INDICATION CHART Gauge indication Refrigerant cycle Probable cause Corrective action [C] High-pressure side is too low and low-pressure side is too high. High- and low-pressure sides become equal soon after compressor operation stops. Compressor pressure operation is improper. ↓ Damaged inside compressor packings. Replace compressor. No temperature difference between high- and low-pressure sides. Compressor pressure operation is improper. ↓ Damaged inside compressor packings. Replace compressor
Scheme 174
Both High- and Low-pressure Sides are Too Low
GAUGE INDICATION CHART Gauge indication Refrigerant cycle Probable cause Corrective action [D] Both high- and low-pressure sides are too low. There is a big temperature difference between liquid tank outlet and inlet. Outlet temperature is extremely low. Liquid tank inlet and expansion valve are frosted. Liquid tank inside is slightly clogged. Replace liquid tank. Check oil for contamination. Temperature of expansion valve inlet is extremely low as compared with areas near liquid tank. Expansion valve inlet may be frosted. Temperature difference occurs somewhere in high-pressure side. High-pressure pipe located between liquid tank and expansion valve is clogged. Check and repair malfunctioning parts. Check oil for contamination. Expansion valve and liquid tank are warm or only cool when touched. Low refrigerant charge. ↓ Leaking fittings or components. Check refrigerant system for leaks. Refer to CHECKING OF REFRIGERANT LEAKS There is a big temperature difference between expansion valve inlet and outlet while the valve itself is frosted. Expansion valve closes a little compared with the specification. ↓ Improper expansion valve adjustment. Malfunctioning expansion valve. Outlet and inlet may be clogged. Remove foreign particles by using compressed air. Check oil for contamination. An area of the low-pressure pipe is colder than areas near the evaporator outlet. Low-pressure pipe is clogged or crushed. Check and repair malfunctioning parts. Check oil for contamination. Air flow volume is too low. Evaporator is frozen. Check intake sensor circuit. Refer to INTAKE SENSOR CIRCUIT CHECK . Replace compressor. Repair evaporator fins. Replace evaporator. Refer to BLOWER MOTOR CIRCUIT CHECK
Scheme 175
Low-pressure Side Sometimes Becomes Negative
GAUGE INDICATION CHART Gauge indication Refrigerant cycle Probable cause Corrective action [E] Low-pressure side sometimes becomes negative. Air conditioning system does not function and does not cyclically cool the compartment air. The system constantly functions for a certain period of time after compressor is stopped and restarted. Refrigerant does not discharge cyclically. ↓ Moisture is frozen at expansion valve outlet and inlet. ↓ Water is mixed with refrigerant. Drain water from refrigerant or replace refrigerant. Replace liquid tank
Scheme 176
Low-pressure Side Becomes Negative
GAUGE INDICATION CHART Gauge indication Refrigerant cycle Probable cause Corrective action [F] Low-pressure side becomes negative. Liquid tank or front/rear side of expansion valve's pipe is frosted or dewed. High-pressure side is closed and refrigerant does not flow. ↓ Expansion valve or liquid tank is frosted. Leave the system at rest until no frost is present. Start it again to check whether or not the malfunction is caused by water or foreign particles. If water is the cause, initially cooling is okay. Then the water freezes causing a blockage. Drain water from refrigerant or replace refrigerant. If due to foreign particles, remove expansion valve and remove the particles with dry and compressed air (not shop air). If either of the above methods cannot correct the malfunction, replace expansion valve. Replace liquid tank. Check oil for contamination
Scheme 177
Insufficient Heating
SYMPTOM: Insufficient heating