AIR CONDITIONING SYSTEM, Diagnostic DTC:B1384

DTC Code DTC Name
B1384 Heating Electric Expansion Valve Circuit

DESCRIPTION

The No. 1 air conditioning accessory assembly (electric expansion valve (heating)) is installed to the accumulator and accessory assembly and is partially open when the power switch is off. When the power switch is on (IG), the heat pump air-conditioning control operates the stepping motor and adjusts the opening amount of the No. 1 air conditioning accessory assembly (electric expansion valve (heating)). When the heat pump air-conditioning control is in cooling mode, the No. 1 air conditioning accessory assembly (electric expansion valve (heating)) is open based on the signal from the heat pump ECU assembly. When the heat pump air-conditioning control is in series heating/parallel heating/heating/gas injection heating mode, the No. 1 air conditioning accessory assembly (electric expansion valve (heating)) 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
B1384 Heating Electric Expansion Valve Circuit When the motor is being operated, there is an open or short in the No. 1 air conditioning accessory assembly (electric expansion valve (heating)) circuit or the No. 1 air conditioning accessory assembly (electric expansion valve (heating)) is overheating

  • Harness or connector

  • Heat pump ECU assembly

  • No. 1 air conditioning accessory assembly (electric expansion valve (heating))

Memorized

(4 sec. or more)*

WIRING DIAGRAM

A003MBXE04
*a Driver IC
*b No. 1 Air Conditioning Accessory Assembly (Electric Expansion Valve (Heating))
*c Heat Pump ECU Assembly

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (NO. 1 AIR CONDITIONING ACCESSORY ASSEMBLY (ELECTRIC EXPANSION VALVE (HEATING)) - HEAT PUMP ECU ASSEMBLY)


    1. Disconnect the A43 No. 1 air conditioning accessory assembly (electric expansion valve (heating)) 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
      A43-1 (VOL-) - A42-15 (AOR2) Always Below 1 Ω
      A43-4 (VOL+) - A42-16 (AOR1) Always Below 1 Ω
      A43-5 (TX+) - A42-35 (AOR4) Always Below 1 Ω
      A43-2 (TX-) - A42-36 (AOR3) Always Below 1 Ω
      A43-1 (VOL-) or A42-15 (AOR2) - Body ground Always 10 kΩ or higher
      A43-4 (VOL+) or A42-16 (AOR1) - Body ground Always 10 kΩ or higher
      A43-5 (TX+) or A42-35 (AOR4) - Body ground Always 10 kΩ or higher
      A43-2 (TX-) or A42-36 (AOR3) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. INSPECT NO. 1 AIR CONDITIONING ACCESSORY ASSEMBLY (ELECTRIC EXPANSION VALVE (HEATING))


    1. A003LS8C01
      *a

      Component without harness connected

      (No. 1 air conditioning accessory assembly (electric expansion valve (heating)))

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A43-1 (VOL-) - A43-4 (VOL+) 20°C (68°F) 8 to 10 Ω
      A43-2 (TX-) - A43-5 (TX+) 20°C (68°F) 8 to 10 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE HEAT PUMP ECU ASSEMBLY Click here

    NG

    REPLACE NO. 1 AIR CONDITIONING ACCESSORY ASSEMBLY (ELECTRIC EXPANSION VALVE (HEATING)) Click here