Inspection Procedure

1. Remove the A/C amplifier with connectors still connected.
2. Start the engine and press the A/C switch.
   Fig 1: Identifying D37 Terminals

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3. Measure the waveform according to the condition in the table below.

   Standard 

   TESTER CONNECTION AND SPECIFIED CONDITION
   
   

   Tester connection (Symbols)	Condition	Specified condition
   D37-28 (TACO) - Body ground	Engine running A/C switch: ON	Pulse generation (See WAVEFORM )

   OK: 

   Wave form appears as shown in the illustration. 

Fig 2: Identifying Waveform Graph

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OK:  Go to step  3

NG: Go to Next Step 

1. Disconnect the connector from A/C amplifier.
   Fig 3: Identifying A/C Amplifier Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the connector from the ECM.
3. Measure the resistance according to the value (s) in the table below.

   Standard 

   TESTER CONNECTION AND SPECIFIED CONDITION
   
   

   Tester connection (Symbols)	Condition	Specified condition
   D37-28 (TACO) - D41-1 (TACH)	Always	Below 1 Ω
   D37-28 (TACO) - Body ground	Always	10 kΩ or higher

Fig 4: Identifying D41 Connector Terminals (TACH)

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NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: GO TO SFI SYSTEM SFI SYSTEM 

1. Remove the A/C amplifier with connectors still connected.
2. Start the engine and press the AUTO switch.
   Fig 5: Identifying D37 Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Measure the waveform according to the condition in the table below.

   Standard 

   TESTER CONNECTION AND SPECIFIED CONDITION
   
   

   Tester connection (Symbols)	Condition	Specified condition
   D37-9 (LOCK) - D37-17 (SG-3)	Engine running Magnetic clutch ON Blower switch: ON	Pulse generation (See WAVEFORM )

   Result 

   RESULT DESCRIPTION
   
   

   Result	Proceed to
   NG	A
   OK (Checking from the PROBLEM SYMPTOMS TABLE )	B
   OK (Checking from the DTC)	C

B: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN  PROBLEM SYMPTOMS TABLE  

C: REPLACE AIR CONDITIONING AMPLIFIER 

Fig 6: Waveform Graph

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A: Go to Next Step 

1. Disconnect the A/C lock sensor (with magnet clutch compressor assembly) connector.
   Fig 7: Identifying A/C Lock Sensor Connector

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2. Measure the resistance according to the value (s) in the table below.

   Resistance 

   RESISTANCE SPECIFICATIONS
   
   

   Tester connection	Condition	Specified condition
   D37-28 (TACO) - D41-1 (TACH)	at 20°C (68°F)	160 to 320 Ω

Fig 8: Identifying D41 Connector Terminals (TACH)

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NG: REPLACE A/C LOCK SENSOR (VW MAGNET CLUTCH COMPRESSOR ASSEMBLY) 

OK: Go to Next Step 

1. Disconnect the connector from A/C lock sensor (w/ magnet clutch compressor assembly).
   Fig 9: Identifying Wire Harness Side Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the connector from the A/C amplifier.
Fig 10: Identifying Air Conditioning Amplifier Connector Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Measure the resistance according to the value (s) in the table below.

Standard 

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: REPLACE AIR CONDITIONING AMPLIFIER