DTC B1421/21: Solar Sensor Circuit (Passenger Side): Procedure

1. Connect Techstream to the DLC3.
2. Turn the ignition switch on (IG) and turn Techstream main switch on.
3. Select the item below in the Data List, and read the value displayed on Techstream.
   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 (Checking from PROBLEM SYMPTOMS TABLE)	B
   OK (Checking from DTC)	C

B → See step   8 

C → See step   6 

A: Go to next step 

1. Disconnect the F2 solar sensor connector.
   Fig 1: Identifying F2 Solar Sensor Connector End View

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the voltage according to the value(s) in the table below.

   Standard voltage

   Tester Connection	Condition	Specified Condition
   F2-6 (CLTB) - F2-3 (CLTE)	Ignition switch off	Below 1 V
   F2-6 (CLTB) - F2-3 (CLTE)	Ignition switch on (IG)	11 to 14 V

OK → See step   4 

NG: Go to next step 

1. Disconnect the D7 main body ECU connector.
   Fig 2: Checking Harness And Connector (Main Body ECU - Solar Sensor)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the F2 solar sensor connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   D7-20 (CLTB) - F2-6 (CLTB)	Always	Below 1 Ω
   D7-18 (CLTE) - F2-3 (CLTE)	Always	Below 1 Ω
   D7-20 (CLTB) - Body ground	Always	10 kΩ or higher
   D7-18 (CLTE) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK) 

1. Remove the solar sensor. Refer to REMOVAL - Step 49 with its connector still connected.
   Fig 3: Checking Solar Sensor

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Connect the battery's positive (+) lead to terminal 6 (CLTB) and the negative (-) lead to terminal 3 (CLTE) of the solar sensor.
3. Measure the voltage according to the value(s) in the table below.

   Standard voltage

   Tester Connection	Condition	Specified Condition
   F2-2 (TSR) - F2-3 (CLTE)	Sensor is subjected to electric light	0.8 to 4.3 V
   F2-2 (TSR) - F2-3 (CLTE)	Sensor is covered with a cloth	Below 0.8 V

   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 6 and positive (+) lead to terminal 3 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.

   HINT: 

   • 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 → See step   7 

OK: Go to next step 

1. Disconnect the F2 solar sensor connector.
   Fig 4: Checking Harness And Connector (Solar Sensor - Air Conditioning Amplifier)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the D37 air conditioning amplifier connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   D37-32 (TSP) - F2-2 (TSR)	Always	Below 1 Ω
   D37-32 (TSP) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   6