2002 Air Conditioning: Diagnosis Lexus IS I

PROBLEM SYMPTOMS TABLE

Use the table below to help you find the cause of the problem. The numbers indicate the priority of the likely cause of the problem. Check each part in order If necessary, replace these parts.

Problem Symptoms

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1. Inspect Drive Belt's Installation Condition Check that the drive belt fits properly in the ribbed grooves.
2. Inspect Drive Belt Tension Check that the arrow mark on the belt tensioner falls within area "A" of the scale. If it is out side area "A", replace the drive belt. HINT: When a new belt is installed, it should be lie within area B.

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1. Remove Engine Under Cover
2. Remove Drive Belt Using SST, loosen the drive belt tension by turning the drive belt tensioner arm clockwise from the bottom side, and remove the drive belt. SST 09216-00041

ON-VEHICLE INSPECTION

1. Inspect Hose And Tube Connections For Looseness
2. Inspect Hoses And Tubes For Leakage Using a gas leak detector, check for leakage of refrigerant.

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1. Discharge Refrigerant From Refrigeration System
2. Replace Faulty Tube Or Hose NOTE: Cap the open fittings immediately to keep moisture or dirt out of the system.
3. Tighten Joint Of Bolt Or Nut To Specified Torque NOTE: Connections should not be torqued tighter than the specified torqued.
4. Evacuate Air From Refrigeration System And Charge System With Refrigerant Specified Amount: 600 +/- 50 G (21.16 +/- 1.76 Oz.)
5. Inspect For Leakage Of Refrigerant Using a gas leak detector, check for leakage of refrigerant.
6. Inspect Air Conditioning Operation

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1. Discharge Refrigerant From Refrigeration System HINT: At the time of installation, please refer to the following item. Evacuate air from refrigeration system. Charge system with refrigerant and inspect for leakage of refrigerant. Specified amount: 600 +/- 50 g (21.16 +/- 1.76 oz.)
2. Drain Engine Coolant From Radiator HINT: It is not necessary to drain out all coolant.
3. Disconnect Liquid Tube And Suction Hose From A/C Unit Remove the bolt and slide the plate, then disconnect the both tubes. Torque: 10 N.m (100 kgf.cm, 7 ft.lbf) NOTE: Cap the open fittings immediately to keep moisture or dirt out of the system. HINT: At the time of installation, please refer to the following item. Lubricate 2 new O-rings with compressor oil and install them to the tubes.
4. Disconnect Water Hoses From Heater Radiator Pipes Grip the claws of the hose clip and slide the hose clip along the hose. Disconnect the water hose.
5. Remove Cooler No. 1 Grommet
6. Remove Heater Pipe Grommet
7. Remove Drain Hose Grommet
8. Remove Instrument Panel And Reinforcement (See «REMOVAL & INSTALLATION»(ref-154166-S35088291742003050700000) )
9. Remove Blower Unit (See «REMOVAL»(ref-174966-S40589498222005041300000) )
10. Remove 2 Air Ducts Slide the floor carpet backward. Remove the air ducts LH, RH.
11. REMOVE A/C UNIT Disconnect the connectors. Disconnect the wire harness clamps. Remove the 2 nuts, 2 bolt and A/C unit.

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1. Remove Wire Harness
2. Remove Drain Hose
3. Remove Heater Radiator Remove the screw and clamp. Pull out the heater radiator.
4. Remove Blower Motor Control Relay Remove the screw and blower motor control relay.
5. Remove Air Mix Servomotor Remove the 3 screws and servomotor.
6. Remove Air Outlet Servomotor Remove the 2 screws and servomotor.
7. Remove Expansion Valve Pry out the packing. HINT: At the time of reassembly, please refer to the following item. Do not reuse the packing. Using SST, remove the 2 bolts, then separate the expansion valve, and tube connector. SST 07110-61050 Torque: 4.1 N.m (42 kgf.cm, 36 in.lbf) HINT: At the time of reassembly, please refer to the following item. Lubricate 4 new O-rings with compressor oil and install them to the valve.
8. Remove Evaporator Temperature Sensor Using a screwdriver, pull out the sensor with bracket plate. HINT: Tape the screwdriver tip before use. Release the 2 claws and sensor from bracket plate.
9. Remove Evaporator Remove air mix servomotor. Disconnect the connector. Remove the 3 screws and servomotor. Remove tube and accessory. Pry out packing. HINT: At the time of installation, please refer to the following item. Do not reuse the packing. Using SST, remove the 2 bolts and the tube and accessory. SST 07110-61050 Torque: 4.1 N.m (42 kgf.cm, 36 in.lbf) NOTE: Cap the open fittings immediately to keep moisture or dirt out of the system. HINT: At the time of installation, please refer to the following item. Lubricate 2 new O-rings with compressor oil and install them to the tube. Remove screw and drain pipe. Remove evaporator. Remove the screw and drain hose. Remove the 4 screws and cover. Pull out the evaporator. HINT: At the time of installation, please refer to the following item. If evaporator is replaced, add compressor oil to evaporator. Add 40 cc (1.4 fl.oz.) Compressor oil: ND-OIL 8 or equivalent Remove Insulator From Heater Case Remove Air Duct

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1. Inspect Air Mix Servomotor Inspect the air mix servomotor operation. Connect the positive (+) lead from the battery to terminal 7 and negative (-) lead to terminal 6, then check that the arm turns to "COOL" side smoothly. Connect the positive (+) lead from the battery to terminal 6 and negative (-) lead to terminal 7, then check that the arm turns to "WARM" side smoothly. If operations are not as specified, replace the servomotor. Inspect position sensor resistance. Measure resistance between terminals at servomotor arm each position as shown in the chart. If resistance is not as specified, replace the servomotor.
2. Inspect Evaporator Check evaporator fins for blockage. If the fins are clogged, clean them with compressed air. NOTE: Never use water to clean the evaporator. Check fitting for cracks or scratches. If necessary, repair or replace.
3. Inspect Heater Radiator Inspect fins for blockage. If the fins are clogged, clean them with compressed air.

1. Inspect Condenser Fins For Blockage Or Damage If the fins are clogged, wash them with water and dry with compressed air. NOTE: Be careful not to damage the fins. If the fins are bent, straighten them with a screwdriver or pliers.
2. Inspect Condenser And Fittings For Leakage Of Refrigerant Using a gas leak detector, check for leakage of refrigerant. If there is leakage, check the tightening torque at the joints.

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1. Discharge Refrigerant From Refrigeration System HINT: At the time of installation, please refer to the following item. Evacuate air from refrigeration system. Charge system with refrigerant and inspect for leakage of refrigerant. Specified amount: 600 +/- 50 g (21.16 +/- 1.76 oz.)
2. Remove Air Cleaner Duct And Air Cleaner Assembly
3. Remove ECU Outlet Duct
4. Remove 2 Radiator Upper Supports Remove the 2 bolts and upper supports.
5. Disconnect Discharge Hose And Liquid Tube Remove the 2 bolts and disconnect the hose and tube. Torque: 10 N.m (100 kgf.cm, 7 ft.lbf) NOTE: Cap the open fittings immediately to keep moisture or dirt out of the system. HINT: At the time of installation, please refer to the following item. Lubricate 2 new O-rings with compressor oil and install them to the hose and tube.
6. Remove Condenser Remove the 4 bolts and 2 brackets. Push the radiator toward engine. Push the condenser toward radiator and pull it upward. HINT: At the time of installation, please refer to the following item. If condenser is replaced, add compressor oil to the condenser. Add 40 cc (1.4 fl. oz) Compressor oil: ND - OIL 8 or equivalent

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1. Using a hexagon wrench (10 mm, 0.39 in.), remove the cap from the modulator.
2. Remove the filter from the modulator.
3. Using pliers, remove the dryer.
4. Insert a new dryer into the modulator. NOTE: Do not remove the dryer from a vinyl bag until inserting it into the modulator Install the dryer with its 2 layered part faced upward to the modulator.
5. Insert the filter into the modulator. NOTE: Install the filter with its protrusion faced downward to the modulator.
6. Install the cap to the modulator. Apply compressor oil to the O-rings and screw part of the cap. Compressor oil: ND-OIL 8 or equivalent Using a hexagon wrench (10 mm, 0.39 in.), install the caps. Torque: 12.3 N.m (125 kgf.cm, 9 ft.lbf)

1. Check Quantity Of Gas During Refrigeration Cycle
2. Set On Manifold Gauge Set (See «MANIFOLD GAUGE SET»(ref-174966-S03291344402005041300000) )
3. Run Engine Run the engine at 1,500 RPM for at least 5 minutes. Then check that the high pressure reading is 1.37 - 1.57 MPa (14 - 16 kgf/cm 2 , 199 - 228 psi).
4. Check Expansion Valve If the expansion valve is faulty, the low pressure reading will drop to 0 kPa (0 kgf/cm 2 , 0 psi).

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1. Discharge Refrigerant From Refrigeration System HINT: At the time of installation, please refer to the following item. Evacuate air from refrigeration system. Charge system with refrigerant and inspect for leakage of refrigerant. Specified amount: 600 +/- 50 g (21.16 +/- 1.76 oz.)
2. Remove Instrument Panel (See «REMOVAL & INSTALLATION»(ref-154166-S35088291742003050700000) )
3. Remove Expansion Valve Pry out the packings. HINT: At the time of installation, please refer to the following item. Do not reuse the packing. Using SST, remove the 4 bolts and separate the expansion valve and tube and accessory. SST 07110-61050 Torque: 4.1 N.m (42 kgf.cm, 36 in.lbf) NOTE: Cap the open fittings immediately to keep moisture or dirt out of the system. HINT: At the time of installation, please refer to the following item. Lubricate 6 new O-rings with compressor oil and install them to the tube and valve.