Air Conditioning. Dtc B1421/21 Solar Sensor Circuit (Passenger Side)

Heater & Air Conditioning System. Lexus Is250, Is220D. Gse20 Ale20

Air Conditioning. Lexus Is250, Is220D. Gse20 Ale20

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE OF INTELLIGENT TESTER

CHECK WIRE HARNESS (SOLAR SENSOR)

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

CHECK SOLAR SENSOR

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

DTC B1421/21 Solar Sensor Circuit (Passenger Side)

DESCRIPTION

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	Solar sensor Harness and connector between solar sensor and A/C amplifier Harness and connector between solar sensor and main body ECU (cowl side junction block ECU RH) A/C amplifier

WIRING DIAGRAM

INSPECTION PROCEDURE

HINT:

If DTC B1244 is output at the same time, troubleshoot DTC B1244 first.
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

Connect the intelligent tester to the DLC3.

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

Expose the sensing portion of the solar sensor to light.
HINT:
Use an incandescence light for inspection.

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

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

REPLACE AIR CONDITIONING AMPLIFIER

A

2.CHECK WIRE HARNESS (SOLAR SENSOR)

Disconnect the solar sensor connector.

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

Go to step 4

NG

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

Disconnect the main body ECU RH connector.

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

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE MAIN BODY ECU RH

4.CHECK SOLAR SENSOR

Remove the solar sensor with its connector still connected.

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

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.

REPLACE SOLAR SENSOR

OK

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

Disconnect the solar sensor connector.

Disconnect the A/C amplifier connector.

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

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE AIR CONDITIONING AMPLIFIER

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

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