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 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 Open or short in the compressor lock sensor circuit.

  • Cooler compressor assembly

  • Compressor drive belt

  • Harness or connector

  • Air conditioning amplifier assembly

  • CAN communication system

WIRING DIAGRAM

B007TUWE21

INSPECTION PROCEDURE

Tech Tips

As DTC B1422 is also output when the compressor drive belt is damaged or loose, inspect the belt before performing troubleshooting.

PROCEDURE


  1. CHECK CAN COMMUNICATION SYSTEM


    1. Use the GTS to check if the CAN communication system is functioning normally.

      Result
      Result Proceed to
      CAN DTC is not output A
      CAN DTC is output B

    B

    GO TO CAN COMMUNICATION SYSTEM Click here

    A

  2. INSPECT COOLER COMPRESSOR ASSEMBLY


    1. Remove the cooler compressor assembly (A/C lock sensor) Click here.

    2. Inspect the cooler compressor assembly (A/C lock sensor) Click here.


    NG

    REPLACE COOLER COMPRESSOR ASSEMBLY Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - A/C LOCK SENSOR)


    1. Disconnect the H18 air conditioning amplifier assembly connector.

    2. Disconnect the D14 cooler compressor assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H18-28 (LOCK) - D14-1 Always Below 1 Ω
      H18-31 (SG-1) - D14-2 Always Below 1 Ω
      H18-28 (LOCK) - Body ground Always 10 kΩ or higher
      H18-31 (SG-1) - 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