DTC B1387-19: A/C Cooling Electric Expansion Valve Circuit Current Above Threshold [08/2023 - ]: Procedure
WARNING: This page is about a different car, the 2025 Lexus RX 450h+ and 2024 Lexus RX 450h+. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK HARNESS AND CONNECTOR (COOLING ELECTRIC EXPANSION VALVE (COOLER EXPANSION VALVE) - HEAT PUMP ECU ASSEMBLY)
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
- CHECK COOLING ELECTRIC EXPANSION VALVE (COOLER EXPANSION VALVE)
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.
*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 - ]