Last Modified: 11-29-2007 1.6 C
Service Category: Vehicle Interior Section: Heating/Air Conditioning
Model Year: 2008 Model: Sequoia Doc ID: RM000002VXE002X
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM: DESCRIPTION (2008 Sequoia)

DTC

B1421/21

Solar Sensor Circuit (Passenger Side)

DESCRIPTION

The Automatic light control sensor (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 current from the solar sensor varies according to the amount of sunlight. When the sunlight increases, the output current increases. As the sunlight decreases, the output current decreases. The air conditioning amplifier detects output current from the automatic light control sensor (solar sensor).



DTC Code

DTC Detection Condition

Trouble Area

B1421/21

Open or short in passenger side solar sensor circuit
  • Automatic light control sensor (solar sensor)
  • Harness or connector between automatic light control sensor (solar sensor) and air conditioning amplifier
  • Harness or connector between automatic light control sensor (solar sensor) and main body ECU
  • Main body ECU
  • Air conditioning amplifier

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1.

READ VALUE USING TECHSTREAM (SOLAR SENSOR (P SIDE))

(a) Connect the Techstream to DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Air Conditioner / Data List / Solar Sensor (P Side).

(e) According to the display on the Techstream, read the 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 voltage increases as brightness increases

Open in circuit: 0

Short in circuit: 255

OK:

The display is as specified in the normal condition.

Result

Result

Proceed to

NG

A

OK (When troubleshooting according to Problem Symptoms Table)

B

OK (When troubleshooting according to the DTC output)

C
A

2.

CHECK HARNESS AND CONNECTOR (SOLAR SENSOR SYSTEM VOLTAGE)

(a) Disconnect the I21 Automatic light control sensor (solar sensor) connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

I21-3 (CLTE) - Body ground

Always

Below 1 Ω

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

I21-6 (CLTB) - I21-3 (CLTE)

Ignition switch ON

11 to 14 V

Ignition switch off

Below 1 V

(d) Reconnect the automatic light control sensor (solar sensor) connector.

OK

3.

CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - AUTOMATIC LIGHT CONTROL SENSOR)

(a) Disconnect the H24 air conditioning amplifier connector.

(b) Disconnect the I21 automatic light control sensor (solar sensor) connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

H24-32 (TSP) - I21-2 (TSR)

Always

Below 1 Ω

H24-32 (TSP) or I21-2 (TSR) - Body ground

Always

10 kΩ or higher

(d) Reconnect the solar sensor connector.

(e) Reconnect the air conditioning amplifier connector.

OK

4.

CHECK AUTOMATIC LIGHT CONTROL SENSOR (SOLAR SENSOR (TSR - CLTE VOLTAGE))

(a) Remove the automatic light control sensor (solar sensor) with its connector still connected HEATING / AIR CONDITIONING: SOLAR SENSOR: REMOVAL (2008 Sequoia) .

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

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

Standard voltage:

Tester Connection

Condition

Specified Condition

2 (TSR) - 3 (CLTE)

Sensor is subjected to electric light

0.8 to 4.3 V

Sensor is covered with a cloth

Below 0.8 V

HINT:

  • As the inspection light is moved away from the sensor, the voltage decreases.
  • Use an incandescent light for inspection. Bring it about 30 cm (11.8 in.) from the solar sensor.

(d) Reinstall the Automatic light control sensor (solar sensor) sensor.

OK

5.

CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - SOLAR SENSOR, BODY GROUND)

(a) Disconnect the H3 main body ECU connector.

(b) Disconnect the I21 automatic light control sensor (solar sensor) connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

H3-18 (CLTE) - I21-3 (CLTE)

Always

Below 1 Ω

H3-20 (CLTB) - I21-6 (CLTB)

Always

Below 1 Ω

H3-18 (CLTE) or I21-3 (CLTE) - Body ground

Always

10 kΩ or higher

H3-20 (CLTB) or I21-6 (CLTB) - Body ground

Always

10 kΩ or higher

(d) Reconnect the automatic light control sensor (solar sensor) connector.

(e) Reconnect the main body ECU connector.

OK