DTC B1387-18: A/C Cooling Electric Expansion Valve Circuit Current Below Threshold [08/2023 - ]: Procedure

Pre-procedure1

• Disconnect the q1 cooling electric expansion valve (cooler expansion valve) connector.
• Disconnect the A61 heat pump ECU assembly connector.

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

  Standard Resistance

  Tester Connection	Condition	Specified Condition	Result
  q1-1 (HPR-) - A61-25 (CEA2)	Always	Below 1 Ω	Ω
  q1-4 (HPR+) - A61-13 (CEA1)	Always	Below 1 Ω	Ω
  q1-5 (HPL+) - A61-14 (CEB1)	Always	Below 1 Ω	Ω
  q1-2 (HPL-) - A61-26 (CEB2)	Always	Below 1 Ω	Ω
  q1-1 (HPR-) or A61-25 (CEA2) - Other terminals and body ground	Always	10 kΩ or higher	kΩ
  q1-4 (HPR+) or A61-13 (CEA1) - Other terminals and body ground	Always	10 kΩ or higher	kΩ
  q1-5 (HPL+) or A61-14 (CEB1) - Other terminals and body ground	Always	10 kΩ or higher	kΩ
  q1-2 (HPL-) or A61-26 (CEB2) - Other terminals and body ground	Always	10 kΩ or higher	kΩ

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  2

Pre-procedure1

• Disconnect the q1 cooling electric expansion valve (cooler expansion valve) connector.

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

  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

  *a	Component without harness connected (Cooling Electric Expansion Valve (Cooler Expansion Valve))

  Standard Resistance

  Tester Connection	Condition	Specified Condition	Result
  1 (HPR-) - 4 (HPR+)	20°C (68°F)	8 to 10 Ω	Ω
  2 (HPL-) - 5 (HPL+)	20°C (68°F)	8 to 10 Ω	Ω

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None

Result: 

OK 

REPLACE HEAT PUMP ECU ASSEMBLY. Refer to  REMOVAL [08/2023 - ] 

Result: 

NG 

REPLACE COOLING ELECTRIC EXPANSION VALVE (COOLER EXPANSION VALVE). Refer to  REMOVAL [08/2023 - ]