Dtc B1421/21 Solar Sensor Circuit (Passenger Side)

Heater & Air Conditioning System. Lexus Gs430, Gs300. Uzs190 Grs190
Air Conditioning. Lexus Gs430, Gs300. Uzs190 Grs190

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE OF INTELLIGENT TESTER

INSPECT MULTIPLEX NETWORK BODY ECU

CHECK WIRE HARNESS (SOLAR SENSOR - MULTIPLEX NETWORK BODY ECU)

CHECK WIRE HARNESS (SOLAR SENSOR - A/C AMPLIFIER)

CHECK SOLAR SENSOR

DTC B1421/21 Solar Sensor Circuit (Passenger Side)


DESCRIPTION

Lexus Gs430, Gs300. Uzs190 Grs190.Air Conditioning.Air Conditioning System. Dtc B1421/21 Solar Sensor Circuit (Passenger Side)
The solar sensor, which is installed on the upper side of the instrument panel, detects sunlight and controls the air conditioning in AUTO mode. The output voltage from the solar sensor varies according to 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 output voltage from the solar sensor.

DTC No.
DTC Detection Condition
Trouble Area
B1421/21
Open or short in passenger side solar sensor circuit
  1. Solar sensor
  2. Harness and connector between solar sensor and A/C amplifier
  3. A/C amplifier
HINT:
If DTC B1224 is output at the same time, troubleshoot DTC B1224 first.

WIRING DIAGRAM


Lexus Gs430, Gs300. Uzs190 Grs190.Air Conditioning.Air Conditioning System. Dtc B1421/21 Solar Sensor Circuit (Passenger Side)


INSPECTION PROCEDURE

1.READ VALUE OF INTELLIGENT TESTER

  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch on (IG) and push the intelligent tester main switch on.

  1. Select the item below in the Data List, and read the display on the intelligent tester.


A/C amplifier:
Item
Measure Item / Display
(Range)
Normal Condition
Diagnostic Note
Solar Sensor (P side)
(Solar Sens - P)
Passenger side solar sensor /
Min.: 0, Max.: 255
Passenger side solar sensor voltage increases as brightness increases
-
OK:
The display is as specified in the normal condition.

Result:
NG
A
OK (Checking from the PROBLEM SYMPTOMS TABLE)
B
OK (Checking from the DTC)
C


B
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

C
REPLACE AIR CONDITIONING AMPLIFIER
A


2.INSPECT MULTIPLEX NETWORK BODY ECU
Lexus Gs430, Gs300. Uzs190 Grs190.Air Conditioning.Air Conditioning System. Dtc B1421/21 Solar Sensor Circuit (Passenger Side)

  1. Remove the cowl side junction block RH with its connectors still connected.

  1. Measure the resistance of the multiplex network body ECU.

    Standard resistance:
    Tester Connection
    		Condition
    		Specified Condition
    4 (CLTE) - Body ground
    		Always
    		Below 1 Ω

  1. Measure the voltage of the multiplex network body ECU.

    Standard voltage:
    Tester Connection
    		Condition
    		Specified Condition
    6 (CLTB) - 4 (CLTE)
    		Engine switch on (IG)
    		10 to 14 V
    Engine switch off
    		Below 1 V


NG
REPLACE MULTIPLEX NETWORK BODY ECU
OK


3.CHECK WIRE HARNESS (SOLAR SENSOR - MULTIPLEX NETWORK BODY ECU)
Lexus Gs430, Gs300. Uzs190 Grs190.Air Conditioning.Air Conditioning System. Dtc B1421/21 Solar Sensor Circuit (Passenger Side)

  1. Disconnect the M1 solar sensor connector.

  1. Measure the resistance of the wire harness side connectors.

    Standard resistance:
    Tester Connection
    		Condition
    		Specified Condition
    M1-3 (CLTE) - Body ground
    		Always
    		Below 1 Ω
    M1-6 (CLTB) - M1-3 (CLTE)
    		Engine switch off
    		Below 1 Ω

  1. Measure the voltage of the wire harness side connectors.

    Standard voltage:
    Tester Connection
    		Condition
    		Specified Condition
    M1-6 (CLTB) - M1-3 (CLTE)
    		Engine switch on (IG)
    		10 to 14 V


NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK


4.CHECK WIRE HARNESS (SOLAR SENSOR - A/C AMPLIFIER)
Lexus Gs430, Gs300. Uzs190 Grs190.Air Conditioning.Air Conditioning System. Dtc B1421/21 Solar Sensor Circuit (Passenger Side)

  1. Disconnect the M1 solar sensor connector.

  1. Disconnect the L52 A/C amplifier connector.

  1. Measure the resistance of the wire harness side connectors.

    Standard resistance:
    Tester Connection
    		Condition
    		Specified Condition
    L52-14 (TSP) - M1-1(TSL) *2
    		Always
    		Below 1 Ω
    L52-14 (TSP) - M1-2 (TSR) *1
    		Always
    		Below 1 Ω
    L52-14 (TSP) - Body ground
    		Always
    		10 kΩ or higher
    HINT:
    1. *1: LHD
    2. *2: RHD


NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK


5.CHECK SOLAR SENSOR
Lexus Gs430, Gs300. Uzs190 Grs190.Air Conditioning.Air Conditioning System. Dtc B1421/21 Solar Sensor Circuit (Passenger Side)

  1. Remove the solar sensor with its connector still connected.

  1. Apply battery voltage between terminals 6 (CLTB) and 3 (CLTE) of the solar sensor.

  1. Measure the voltage of the sensor.

    Standard voltage:
    Tester Connection
    		Condition
    		Specified Condition
    1 (TSL) *2 - 3 (CLTE)
    		Sensor is subjected to electric light
    		0.8 to 4.3 V
    2 (TSR) *1 - 3 (CLTE)
    		Sensor is subjected to electric light
    		0.8 to 4.3 V
    1 (TSL) *2 - 3 (CLTE)
    		Sensor is covered with a cloth
    		Below 0.8 V
    2 (TSR) *1 - 3 (CLTE)
    		Sensor is covered with a cloth
    		Below 0.8 V
    NOTICE:
    The connection procedure for using a digital tester such as a TOYOTA electrical tester is shown above. When using an analog tester, connect the positive (+) lead to terminal 2 and negative (-) lead to terminal 1 of the solar sensor.
    HINT:
    1. As the inspection light is moved away from the sensor, the voltage increases.
    2. Use an incandescent light for inspection. Bring it about 30 cm (11.8 in.) from the solar sensor.
    3. *1: LHD
    4. *2: RHD


NG
REPLACE SOLAR SENSOR
OK

REPLACE AIR CONDITIONING AMPLIFIER