DTC B1451: Compressor Solenoid Circuit [12/2019 - 10/2022]: Procedure

1. Disconnect the C59 cooler compressor assembly connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Cooler Compressor Assembly)

2. Using an oscilloscope, check the waveform.

   Item	Content
   Tester Connection	C59-2 (SOL+) - Body ground
   Tool Setting	5 V/DIV., 500 μs./DIV.
   Condition	Engine running Blower switch: LO A/C switch: On

   OK

   Waveform is similar to that shown in the illustration.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE COOLER COMPRESSOR ASSEMBLY. Refer to  REMOVAL [12/2019 - 10/2022] 

Result: 

NG 

See step  2

1. Disconnect the C59 cooler compressor assembly connector.
2. Disconnect the H62 air conditioning amplifier assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   C59-2 (SOL+) - H62-18 (SOL+)	Always	Below 1 Ω
   C59-2 (SOL+) or H62-18 (SOL+) - Other terminals and body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [12/2019 - 10/2022] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR