AIR CONDITIONING SYSTEM (for Automatic Air Conditioning System), Diagnostic DTC:B1451/51

DTC Code DTC Name
B1451/51 Compressor Solenoid Circuit

DESCRIPTION

In this circuit, the compressor receives a refrigerant compression demand signal from the air conditioning amplifier.

Based on this signal, the compressor changes the degree of refrigerant compression.

DTC No. DTC Detection Condition Trouble Area
B1451/51 Open or short in solenoid of externally changeable compressor circuit

  • Compressor and magnetic clutch

  • Wire harness between air conditioning amplifier and compressor and pulley

  • Air conditioning amplifier

WIRING DIAGRAM

A017FN6E36

INSPECTION PROCEDURE

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (REG CTRL CURRNT)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch on (IG) and turn the intelligent tester main switch on.

    3. Select the items below in the Data List, and read the value displayed on the intelligent tester.

      Data List / Air Conditioner:
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Reg Ctrl Currnt

      Regulator control current /

      Min.: 0 A

      Max.: 0.997 A

      		 Value changes between 0 A and 0.997 A in accordance with compressor operation -
      OK
      The display is as specified in the normal condition column.
      Result
      Result Proceed to
      NG A
      OK (Checking from PROBLEM SYMPTOMS TABLE) B
      OK (Checking from DTC) C

    B

    PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    C

    REPLACE AIR CONDITIONING AMPLIFIER Click here

    A

  2. INSPECT COMPRESSOR AND MAGNETIC CLUTCH


    1. A017BNWE88

      Disconnect the B51 compressor and magnetic clutch connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      B51-1 (SOL-) - B51-2 (SOL+) 25°C (77°F) 10.1 to 11.1 Ω

    NG

    REPLACE COMPRESSOR AND MAGNETIC CLUTCH Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (COMPRESSOR AND MAGNETIC CLUTCH - AIR CONDITIONING AMPLIFIER)


    1. A017BNWE89

      Disconnect the B51 compressor and magnetic clutch connector.

    2. A017G0LE04

      Disconnect the D33 amplifier connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      B51-2 (SOL+) - D33-2 (SOL+) Always Below 1 Ω
      B51-2 (SOL+) - Body Ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (COMPRESSOR AND MAGNETIC CLUTCH - BODY GROUND)


    1. A017DM9E01

      Disconnect the B51 compressor and magnetic clutch connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      B51-1 (SOL-) - Body Ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE AIR CONDITIONING AMPLIFIER Click here