DTC B1244: Light Sensor Circuit Malfunction [08/2015 - 08/2017]: Procedure

1. Clear the DTC (Refer to DTC CHECK / CLEAR [08/2015 - 08/2017] ).
2. Recheck for DTC (Refer to DTC CHECK / CLEAR [08/2015 - 08/2017] ).

   OK

   DTC B1244 is not output.

Result: 

OK 

USE SIMULATION METHOD TO CHECK 

(Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE [08/2015 - 08/2019] )

Result: 

NG 

See step  2

1. Operate the Techstream according to the display and select Data List.
   MAIN BODY
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Illumination Rate	Illumination rate / min.: 0, max.: 99.99	Actual illumination rate is displayed	-

   OK

   Output illumination is as shown in table above.

Result: 

OK 

REPLACE MAIN BODY ECU 

Result: 

NG 

See step  3

1. Disconnect the I21 automatic light control sensor connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

2. 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

3. Reconnect the automatic light control sensor connector.

Result: 

OK 

REPLACE AUTOMATIC LIGHT CONTROL SENSOR 

(Refer to PROCEDURE - Step 69 )

Result: 

NG 

See step  4

1. Disconnect the H3 main body ECU connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

2. Disconnect the I21 automatic light control sensor connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   H3-20 (CLTB) - I21-6 (CLTB)	Always	Below 1 Ω
   H3-19 (CLTS) - I21-5 (CLTS)	Always	Below 1 Ω
   H3-18 (CLTE) - I21-3 (CLTE)	Always	Below 1 Ω
   H3-20 (CLTB) - Body ground	Always	10 kΩ or higher
   H3-19 (CLTS) - Body ground	Always	10 kΩ or higher
   H3-18 (CLTE) - Body ground	Always	10 kΩ or higher

4. Reconnect the automatic light control sensor connector.
5. Reconnect the main body ECU connector.

Result: 

OK 

REPLACE MAIN BODY ECU 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR