Inspection Procedure

INSPECT AIR CONDITIONING AMPLIFIER

Remove the A/C amplifier with connectors still connected.
Start the engine and press the A/C switch.

Fig 1: Identifying D37 Air Conditioning Amplifier Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

Standard

TESTER CONNECTION SPECIFIED CONDITION

Tester Connection	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.

OK: Go to step 3

Fig 2: Waveform Graph

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: Go to Next Step

CHECK HARNESS AND CONNECTOR (ECM - AIR CONDITIONING AMPLIFIER)

Disconnect the connector from A/C amplifier.

Fig 3: Identifying D37 A/C Amplifier Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Disconnect the connector from the ECM.

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

Standard Resistance

STANDARD RESISTANCE SPECIFICATIONS

Tester Connection	Condition	Specified Condition
D37-28 (TACO) - A55-15 (TACH)	Always	Below 1 Ω
D37-28 (TACO) - Body ground	Always	10 kΩ or higher

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

Fig 4: Identifying A55 ECM Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: Go to SFI SYSTEM

INSPECT AIR CONDITIONING AMPLIFIER (LOCK - SG-3)

Remove the A/C amplifier with connectors still connected.
Start the engine and press the AUTO switch.

Fig 5: Identifying D37 Air Conditioning Amplifier Connector (LOCK - SG-3)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

Standard

TESTER CONNECTION SPECIFIED CONDITION

Tester Connection	Condition	Specified Condition
D37-9 (LOCK) - D37-17 (SG-3)	Engine running Magnetic clutch ON Blower switch: ON	Pulse generation (See waveform)

Fig 6: Waveform Graph

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Result

RESULT REFERENCE

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

A: Go to Next Step

INSPECT A/C LOCK SENSOR (W/ MAGNET CLUTCH COMPRESSOR ASSEMBLY)

Disconnect the A/C lock sensor (with magnet clutch compressor assembly) connector.

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

Standard Resistance

STANDARD RESISTANCE SPECIFICATIONS

Tester Connection	Condition	Specified Condition
B8-1 (SSR+) - B8-2 (SSR-)	at 20°C (68°F)	160 to 320 Ω

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

Fig 7: Identifying B8 A/C Lock Sensor Connector (With Magnet Clutch Compressor Assembly)

OK: Go to Next Step

CHECK HARNESS AND CONNECTOR (A/C LOCK SENSOR - AIR CONDITIONING AMPLIFIER)

Disconnect the connector from A/C lock sensor (w/ magnet clutch compressor assembly).

Fig 8: Identifying B8 A/C Lock Sensor Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Disconnect the connector from the A/C amplifier.

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

Standard Resistance

STANDARD RESISTANCE SPECIFICATIONS

Tester Connection	Condition	Specified Condition
D37-9 (LOCK) - B8-1 (SSR+)	Always	Below 1 Ω
D37-17 (SG-3) - B8-2 (SSR-)	Always	Below 1 Ω
D37-9 (LOCK) - Body ground	Always	10 kΩ or higher
D37-17 (SG-3) - Body ground	Always	10 kΩ or higher

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

Fig 9: Identifying D37 A/C Amplifier Connector

OK : REPLACE AIR CONDITIONING AMPLIFIER