AIR CONDITIONING SYSTEM (for Manual Air Conditioning System), Diagnostic DTC:B1422

DTC Code DTC Name
B1422 Compressor Lock Sensor Circuit

SYSTEM DESCRIPTION

The ECM sends the engine speed signal to the air conditioning amplifier assembly via CAN communication.

The air conditioning amplifier assembly sends an air conditioning operation request signal to the ECM via direct line, and the ECM sends a magnet clutch operation permission signal to the air conditioning amplifier assembly via direct line.

The air conditioning amplifier assembly reads the difference between compressor speed and engine speed. When the difference becomes too large, the air conditioning amplifier assembly determines that the cooler compressor assembly is locked and turns the magnet clutch assembly off.

DTC Code DTC Detection Condition Trouble Area
B1422 An open or short in the compressor lock sensor circuit.

  • Cooler compressor assembly

  • Harness or connector

  • Magnet clutch relay (MG CLT)

  • Air conditioning amplifier assembly

  • ECM

  • CAN communication system

WIRING DIAGRAM

A0157X8E01

INSPECTION PROCEDURE

Tech Tips

As DTC B1422 is also output when the fan & generator V-belt is damaged or loose, inspect the belt before performing troubleshooting.

PROCEDURE


  1. CHECK CAN COMMUNICATION SYSTEM


    1. Use the intelligent tester to check if the CAN communication system is functioning normally Click here.

      Result
      Result Proceed to
      CAN DTC is not output A
      CAN DTC is output (for LHD) B
      CAN DTC is output (for RHD) C

    B

    GO TO CAN COMMUNICATION SYSTEM Click here

    C

    GO TO CAN COMMUNICATION SYSTEM Click here

    A

  2. INSPECT MAGNET CLUTCH RELAY (MG CLT)


    1. A015C9EE03

      Remove the magnet clutch relay (MG CLT).

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3 - 5 Battery voltage is not applied to terminals 1 and 2 10 kΩ or higher
      Battery voltage is applied to terminals 1 and 2 Below 1 Ω

    NG

    REPLACE MAGNET CLUTCH RELAY (MG CLT)

    OK

  3. CHECK HARNESS AND CONNECTOR (MAGNET CLUTCH RELAY - BATTERY, AIR CONDITIONING AMPLIFIER AND COOLER COMPRESSOR)


    1. Remove the magnet clutch relay (MG CLT).

    2. Disconnect the E81 air conditioning amplifier assembly connector.

    3. Disconnect the C30 cooler compressor assembly connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      Magnet clutch relay terminal 1 - Body ground Ignition switch ON 11 to 14 V
      Ignition switch off Below 1 V
      Magnet clutch relay terminal 5 - Body ground Ignition switch ON 11 to 14 V
      Ignition switch off Below 1 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Magnet clutch relay terminal 2 - E81-20 (MGC) Always Below 1 Ω
      Magnet clutch relay terminal 3 - C30-3 (MG+)
      Magnet clutch relay terminal 1 - Body ground Always 10 kΩ or higher
      Magnet clutch relay terminal 2 - Body ground
      Magnet clutch relay terminal 3 - Body ground
      Magnet clutch relay terminal 4 - Body ground

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY


    1. A015DOAE36
      Text in Illustration
      *a

      Component with harness connected

      (Air Conditioning Amplifier Assembly)

      Remove the air conditioning amplifier assembly with its connectors still connected Click here.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      E81-20 (MGC) - Body ground

      • Engine idling

      • Blower switch LO level

      • A/C switch on (magnet clutch on permitted)

      		 Below 1 V

      • Engine idling

      • Blower switch LO level

      • A/C switch off or on (magnet clutch on not permitted)

      		 11 to 14 V

    NG

    CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - ECM) Click here

    OK

  5. INSPECT COOLER COMPRESSOR ASSEMBLY


    1. A0157LME03

      Remove the cooler compressor assembly.


    2. Check the magnet clutch operation.

      OK
      Measurement Connection Specified Condition

      Battery positive (+) → 3 (MG+)

      Battery negative (-) → cooler compressor assembly body

      		 Magnet clutch engages

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 (SSR+) - 2 (SSR-) 20°C (68°F) 160 to 320 Ω
      Result
      Result Proceed to
      OK A
      NG (for 1VD-FTV) B
      NG (for 1GR-FE) C

    B

    REPLACE COOLER COMPRESSOR ASSEMBLY Click here

    C

    REPLACE COOLER COMPRESSOR ASSEMBLY Click here

    A

  6. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - COOLER COMPRESSOR)


    1. Disconnect the E81 air conditioning amplifier assembly connector.

    2. Disconnect the C30 cooler compressor connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E81-8 (LOCK) - C30-1 (SSR+) Always Below 1 Ω
      E81-35 (SG-5) - C30-2 (SSR-) Always Below 1 Ω
      E81-8 (LOCK) - Body ground Always 10 kΩ or higher
      E81-35 (SG-5) - Body ground Always 10 kΩ or higher
      Result
      Result Proceed to
      OK (When troubleshooting according to problem symptoms table) A
      OK (When troubleshooting according to the DTC) B
      NG C

    B

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    A

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

  7. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - ECM)


    1. Disconnect the E81 air conditioning amplifier assembly connector.

    2. Disconnect the A38*1 or A52*2 ECM connector.


      • *1: for LHD

      • *2: for RHD

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      E81-17 (AC1) - A38-30 (AC1) Always Below 1 Ω
      E81-27 (ACT) - A38-18 (ACT) Always Below 1 Ω
      E81-17 (AC1) - Body ground Always 10 kΩ or higher
      E81-27 (ACT) - Body ground Always 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      E81-17 (AC1) - A52-30 (AC1) Always Below 1 Ω
      E81-27 (ACT) - A52-18 (ACT) Always Below 1 Ω
      E81-17 (AC1) - Body ground Always 10 kΩ or higher
      E81-27 (ACT) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY


    1. A015DOAE37
      Text in Illustration
      *a

      Component with harness connected

      (Air Conditioning Amplifier Assembly)

      Remove the air conditioning amplifier assembly with its connectors still connected Click here.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      E81-17 (AC1) - Body ground

      • Engine idling

      • Blower switch LO level

      • A/C switch on

      		 Below 1 V

      • Engine idling

      • Blower switch LO level

      • A/C switch off

      		 11 to 14 V
      E81-27 (ACT) - Body ground

      • Engine idling

      • Blower switch LO level

      • A/C switch on (magnet clutch on)

      		 Below 1 V

      • Engine idling

      • Blower switch LO level

      • A/C switch off or on (magnet clutch off)

      		 11 to 14 V

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

  9. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY


    1. Temporarily replace the air conditioning amplifier assembly with a new or normally functioning one Click here.

    2. Check the air conditioning system to check it functions properly.

      OK
      Air conditioning system functions operate normally.
      Result
      Result Proceed to
      OK A
      NG (for 1GR-FE) B
      NG (for 1VD-FTV) C

    B

    REPLACE ECM Click here

    C

    REPLACE ECM Click here

    A

    END (AIR CONDITIONING AMPLIFIER ASSEMBLY IS FAULTY)