AIR CONDITIONING SYSTEM, Diagnostic DTC:B1421/21

DTC Code DTC Name
B1421/21 Solar Sensor Circuit (Passenger Side)

DESCRIPTION

A0161BWE01

The solar sensor, which is installed on the upper side of the instrument panel, detects sunlight and controls air conditioning AUTO mode. The output voltage from the solar sensor varies in accordance with the amount of sunlight. When the sunlight increases, the output voltage increases. As the sunlight decreases, the output voltage decreases. The A/C amplifier detects changes in the output voltage from the solar sensor.

DTC No. DTC Detection Condition Trouble Area
B1421/21 Open or short in passenger side solar sensor circuit

  • Solar sensor

  • Harness or connector between solar sensor and A/C amplifier

  • Harness or connector between solar sensor and main body ECU

  • Main body ECU

  • A/C amplifier

WIRING DIAGRAM

A015YIKE03

INSPECTION PROCEDURE

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the intelligent tester on.

    4. Select the item 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
      Solar Sensor (P Side)

      Passenger side solar sensor /

      Min.: 0, Max.: 255

      		 Passenger side solar sensor value increases as brightness increases -
      OK
      The display is as specified in the normal condition column.
      Result
      Result Proceed to
      NG A
      OK (When troubleshooting according to the Problem Symptoms Table) B
      OK (When troubleshooting according to the DTC) C

    B

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

    C

    REPLACE A/C AMPLIFIER Click here

    A

  2. CHECK SOLAR SENSOR (SENSOR POWER INPUT)


    1. A0162YDE03

      Disconnect the solar sensor connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      K1-6 (CLTB) - K1-3 (CLTE) Engine switch off Below 1 V
      K1-6 (CLTB) - K1-3 (CLTE) Engine switch on (IG) 11 to 14 V

    NG

    CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - SOLAR SENSOR) Click here

    OK

  3. INSPECT SOLAR SENSOR


    1. A0161FGE05

      Remove the solar sensor.

    2. Reconnect the solar sensor connector.

    3. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      K1-2 (TSR) - K1-3 (CLTE)*1 Sensor is subjected to electric light 0.8 to 4.3 V
      K1-2 (TSR) - K1-3 (CLTE)*1 Sensor is covered with a cloth Below 0.8 V
      K1-1 (TSL) - K1-3 (CLTE)*2 Sensor is subjected to electric light 0.8 to 4.3 V
      K1-1 (TSL) - K1-3 (CLTE)*2 Sensor is covered with a cloth Below 0.8 V

      Tech Tips


      • *1: for LHD

      • *2: for RHD

      Note


      • The connection procedure for using a digital tester such as a TOYOTA electrical tester is shown above. When using an analog tester, connect the negative (-) lead to terminal 2*1, 1*2 and positive (+) lead to terminal 6 of the solar sensor.

      • While using the battery during inspection, do not bring the positive and negative tester probes too close to each other as a short circuit may occur.

      Tech Tips


      • Use an incandescent light for inspection. Bring it within about 30 cm (11.8 in.) of the solar sensor.

      • As the inspection light is moved away from the sensor, the voltage decreases.


    NG

    REPLACE SOLAR SENSOR Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (SOLAR SENSOR - AIR CONDITIONING AMPLIFIER)


    1. A0162YDE06

      Disconnect the solar sensor connector.

    2. A0162IGE04

      Disconnect the A/C amplifier connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      J58-14 (TSP) - K1-2 (TSR)*1 Always Below 1 Ω
      J58-14 (TSP) - K1-1 (TSL)*2 Always Below 1 Ω
      J58-14 (TSP) - Body ground Always 10 kΩ or higher

      Tech Tips


      • *1: for LHD

      • *2: for RHD


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE A/C AMPLIFIER Click here

  5. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - SOLAR SENSOR)


    1. A0162MQE01

      Disconnect the main body ECU connector.

    2. A0162YDE03

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      J74-6 (CLTB) - K1-6 (CLTB) Always Below 1 Ω
      J74-4 (CLTE) - K1-3 (CLTE) Always Below 1 Ω
      J74-6 (CLTB) - Body ground Always 10 kΩ or higher
      J74-4 (CLTE) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE MAIN BODY ECU (COWL SIDE JUNCTION BLOCK RH)