Air Conditioning (Diagnostic Codes & Circuit Tests): Diagnosis Lexus GS III рестайлинг

INSPECTION PROCEDURE

HINT

If it can be confirmed that any compressor oil other than ND-OIL 11 has been used in the vehicle, replace the air conditioning cycle.

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1. INSPECT COMPRESSOR ASSEMBLY Clear the DTC. Refer to «DTC CHECK / CLEAR»(ref-387145-S20183754872011022400000) . Turn the power switch ON (IG). Prepare the vehicle according to the table below. Item Condition Blower speed HI Temperature setting MAX COLD A/C ON Turn the power switch OFF. Remove the service plug grip. WARNING: Because the compressor has a high-voltage circuit, wear the insulated gloves and pull out the service plug grip to cut off the high-voltage circuit before inspection. Do not touch the high-voltage connectors or terminals for 10 minutes after the service plug grip is removed. NOTE: Do not start the engine with the service plug grip removed because it may cause a malfunction. Disconnect the w8 compressor connector. Using a megohmmeter, measure the resistance of the connector. Standard resistance Tester Connection Specified Condition w8-1 (PE) - Body ground 2 Mohms or higher w8-2 (PB) - Body ground 2 Mohms or higher NG --> REPLACE COMPRESSOR ASSEMBLY OK: Go to next step
2. INSPECT AIR CONDITIONING CYCLE Reconnect the w8 the compressor connector. Install the service plug grip. Turn the power switch ON (IG). Set the A/C setting temperature to 25°C (77°F) and the blower switch LO and then operate the compressor for 10 minutes to circulate the refrigerant cycle with refrigerant and collect as much compressor as possible. Turn the power switch OFF. Using a spot cooler or other tools, cool down the compressor assembly for 30 minutes, or leave the vehicle overnight before inspection. NOTE: Do not operate the compressor before inspection. Remove the service plug grip. NOTE: Do not start the engine with the service plug grip removed because it may cause a malfunction. Disconnect the w8 compressor connector. Using a megohmmeter, measure the resistance of the connector. Standard resistance Tester Connection Specified Condition w8-1 (PE) - Body ground 3 Mohms or higher w8-2 (PB) - Body ground 3 Mohms or higher NOTE: If the results are out of the specified range, possible causes are poor insulation in the compressor assembly, or mixing of any oil other than ND-OIL 11 in the refrigerant cycle. NG --> REPLACE AIR CONDITIONING CYCLE OK --> REPLACE COMPRESSOR ASSEMBLY

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The blower motor is operated by signals from the A/C amplifier. Blower motor speed signals are transmitted by changes in the duty ratio.

Duty Ratio

The duty ratio is the ratio of the blower motor ON time (A) to the total of the blower motor ON and OFF time (A + B).

The blower motor controller controls the blower motor speed.

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1. PERFORM ACTIVE TEST USING TECHSTREAM Connect the Techstream to the DLC3. Turn the power switch on (IG). Turn the Techstream on. Select the item below in the Active Test and then check that the motor operates. ACTIVE TEST / AIR CONDITIONER Tester Display Test Part Control Range Diagnostic Note Blower Motor (Blower Motor) Blower motor Min.: Level 0, Max.: Level 31 - RESULT Result Proceed to NG (blower motor does not operate) A NG (blower motor operates but does not change speed) B OK C C --> PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN «PROBLEM SYMPTOMS TABLE»(ref-387145-S36094178262011022400000) B --> See step 6 A: Go to next step
2. INSPECT FUSE (HEATER) Remove the HEATER and DC/DC H-fuses from the engine room No. 1 junction block. Measure the resistance of the H-fuses. Standard resistance Below 1 ohms NG --> REPLACE FUSE OK: Go to next step
3. CHECK WIRE HARNESS (BLOWER MOTOR - BODY GROUND) Disconnect the k1 blower motor connector. Measure the resistance of the wire harness side connector. Standard resistance Tester Connection Specified Condition k1-1 (GND) - Body ground Below 1 ohms NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK WIRE HARNESS (BLOWER MOTOR - BATTERY) Disconnect the k1 blower motor connector. Measure the voltage of the wire harness side connector. Standard voltage Tester Connection Specified Condition k1-3 (+B) - Body ground 10 to 14 V NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
5. CHECK BLOWER MOTOR Disconnect the K52 A/C amplifier connector. Measure the voltage of the connector. Standard voltage Tester Connection Condition Specified Condition k1-2 (S1) - Body ground Power switch ON (IG) 4.5 to 5.5 V NG --> See step 8 OK: Go to next step
6. CHECK WIRE HARNESS (A/C AMPLIFIER - BLOWER MOTOR AND BODY GROUND) Disconnect the K52 A/C amplifier connector. Measure the voltage of the wire harness side connector. Standard voltage Tester Connection Condition Specified Condition K52-11 (BLW) - K52-20 (GND) Power switch ON (IG) Blower switch OFF 4.5 to 5.5 V NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
7. CHECK AIR CONDITIONING AMPLIFIER (BLW SIGNAL) Remove the A/C amplifier with its connectors still connected. Turn the power switch ON (IG). Turn the blower switch ON (Lo). Using an oscilloscope, check the waveform 1. WAVEFORM 1 (REFERENCE): Item Contents Test Connector BLW (K52-11) - GND (K52-20) Tool Setting 1 V/DIV., 500 μsec./DIV. Vehicle Condition Power switch: ON (IG) Blower switch: OFF --> ON OK Waveform is as shown in the illustration. HINT: Waveform varies with the blower level. NG --> REPLACE AIR CONDITIONING AMPLIFIER OK --> REPLACE BLOWER MOTOR
8. CHECK WIRE HARNESS (BLOWER MOTOR - A/C AMPLIFIER) Disconnect the K52 A/C amplifier connector. Disconnect the k1 blower motor connector. Measure the resistance of the wire harness side connectors. Standard resistance Tester Connection Specified Condition k1-2 (S1) - K52-11 (BLW) Below 1 ohms k1-2 (S1) - Body ground 10 kohms or higher K52-11 (BLW) - Body ground 10 kohms or higher NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> REPLACE BLOWER MOTOR

HINT

Start the engine before inspection. Check the RH-IG relay 1 or battery if the smart access system with push-button start does not start.

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1. INSPECT FUSE (ECU-IG RH) Remove the ECU-IG RH fuse from the main body ECU RH. Measure the resistance of the fuse. Standard resistance Below 1 ohms NG --> CHECK FOR SHORT IN ALL HARNESSES AND COMPONENTS CONNECTED TO FUSE OK: Go to next step
2. CHECK AIR CONDITIONING AMPLIFIER (IG+ VOLTAGE) Remove the A/C amplifier with its connectors still connected. Turn the power switch ON (IG). Measure the voltage of the connector. Standard voltage Tester Connection Condition Specified Condition K52-21 (IG+) - K52-20 (GND) Power switch ON (IG) 10 to 14 V OK --> PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN «PROBLEM SYMPTOMS TABLE»(ref-387145-S36094178262011022400000) NG: Go to next step
3. CHECK WIRE HARNESS (AIR CONDITIONING AMPLIFIER - BATTERY AND GROUND BODY) Disconnect the K52 A/C amplifier connector. Measure the voltage of the wire harness side connector. Standard voltage Tester Connection Condition Specified Condition K52-21 (IG+) - Body ground Power switch OFF Below 1 V K52-21 (IG+) - Body ground Power switch ON (IG) 10 to 14 V Measure the resistance of the wire harness side connector. Standard resistance Tester Connection Specified Condition K52-20 (GND) - Body ground Below 1 ohms NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> REPLACE AIR CONDITIONING AMPLIFIER