Lexus IS250 · Service Manual HEATER & AIR CONDITIONING SYSTEM

B1421/21

Diagnostic trouble codes

DESCRIPTION

E107008E01
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 voltage output 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. Harness and connector between solar sensor and main body ECU (cowl side junction block ECU RH)
  4. A/C amplifier

WIRING DIAGRAM

E109253E09

INSPECTION PROCEDURE

HINT:
  1. If DTC B1244 is output at the same time, troubleshoot DTC B1244 first.
  2. If the check is performed in a dark place, DTC B1421/21 or B1424/24 (solar sensor circuit abnormal) may be output.


1. READ VALUE OF INTELLIGENT TESTER

  1. Connect the intelligent tester to the DLC3.

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

  1. Expose the sensing portion of the solar sensor to light.

    HINT:
    Use an incandescence light for inspection.

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

Data List / Air Conditioning: 
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 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

C
REPLACE AIR CONDITIONING AMPLIFIER
A


2. CHECK WIRE HARNESS (SOLAR SENSOR)

  1. E107010E05
    Disconnect the solar sensor connector.

  1. 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)
    		 10 to 14 V



OK
Go to step 4
NG


3. CHECK WIRE HARNESS (MAIN BODY ECU RH - SOLAR SENSOR)

  1. E108942E09
    Disconnect the main body ECU RH connector.

  1. 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 RH

4. CHECK SOLAR SENSOR

  1. E109215E10
    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 according to the value(s) in the table below.

    Standard voltage:
    LHD:
    Tester Connection
    		 Condition
    		 Specified Condition
    K1-2 (TSR) - K1-3 (CLTE)
    		 Sensor is subjected to electric light
    		 0.8 to 4.3 V
    K1-2 (TSR) - K1-3 (CLTE)
    		 Sensor is covered with a cloth
    		 Below 0.8 V

    Standard voltage:
    RHD:
    Tester Connection
    		 Condition
    		Specified Condition
    K1-1 (TSL) - K1-3 (CLTE)
    		 Sensor is subjected to electric light
    		 0.8 to 4.3 V
    K1-1 (TSL) - K1-3 (CLTE)
    		 Sensor is covered with a cloth
    		 Below 0.8 V

    NOTICE:
    1. 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 and positive (+) lead to terminal 1 of the solar sensor.
    2. 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.

    HINT:
    1. Use an incandescent light for inspection. Bring it within about 30 cm (11.8 in.) of the solar sensor.
    2. As the inspection light is moved away from the sensor, the voltage increases.



 NG
REPLACE SOLAR SENSOR
OK


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

  1. E116905E05
    Disconnect the solar sensor connector.

  1. Disconnect the A/C amplifier connector.

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

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

    Standard resistance:
    RHD:
    Tester Connection
    		 Condition
    		 Specified Condition
    J58-14 (TSP) -K1-1 (TSL)
    		 Always
    		 Below 1 Ω
    J58-14 (TSP) - Body ground
    		 Always
    		 10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE AIR CONDITIONING AMPLIFIER


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