AIR CONDITIONING SYSTEM, Diagnostic DTC:B1385

DTC Code DTC Name
B1385 Cooling Electric Expansion Valve Circuit

DESCRIPTION

The electric expansion valve (cooling) is installed to the inlet pipe of the No. 1 cooler evaporator assembly and is closed when the power switch is off. When the power switch is on (IG), the heat pump air-conditioning control operates the stepping motor to adjust the opening amount of the electric expansion valve (cooling). When the heat pump air-conditioning control is in heating/gas injection heating mode, the electric expansion valve (cooling) is closed based on the signal from the heat pump ECU assembly. When the heat pump air-conditioning control is in cooling/series heating/parallel heating mode, the electric expansion valve (cooling) is adjusted to optimally control the opening amount based on the signal from the heat pump ECU assembly.

DTC No. Detection Item DTC Detection Condition Trouble Area Memory
B1385 Cooling Electric Expansion Valve Circuit When the motor is being operated, there is an open or short in the electric expansion valve (cooling) circuit or the electric expansion valve (cooling) is overheating

  • Harness or connector

  • Heat pump ECU assembly

  • Electric expansion valve (cooling)

Memorized

(4 sec. or more)*

WIRING DIAGRAM

A003MBXE05

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (ELECTRIC EXPANSION VALVE (COOLING) - HEAT PUMP ECU ASSEMBLY)


    1. Disconnect the A45 electric expansion valve (cooling) connector.

    2. Disconnect the A42 heat pump ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A45-1 (HPR-) - A42-18 (LBM1) Always Below 1 Ω
      A45-4 (HPR+) - A42-19 (LBLO) Always Below 1 Ω
      A45-5 (HPL+) - A42-38 (LBUT) Always Below 1 Ω
      A45-2 (HPL-) - A42-39 (LBM2) Always Below 1 Ω
      A45-1 (HPR-) or A42-18 (LBM1) - Body ground Always 10 kΩ or higher
      A45-4 (HPR+) or A42-19 (LBLO) - Body ground Always 10 kΩ or higher
      A45-5 (HPL+) or A42-38 (LBUT) - Body ground Always 10 kΩ or higher
      A45-2 (HPL-) or A42-39 (LBM2) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. INSPECT ELECTRIC EXPANSION VALVE (COOLING)


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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A45-1 (HPR-) - A45-4 (HPR+) 20°C (68°F) 8 to 10 Ω
      A45-2 (HPL-) - A45-5 (HPL+) 20°C (68°F) 8 to 10 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE HEAT PUMP ECU ASSEMBLY Click here

    NG

    REPLACE ELECTRIC EXPANSION VALVE (COOLING) Click here