DTC B1244: Light Sensor Circuit Malfunction: Procedure

1. Clear the DTCs. Refer to DTC CHECK / CLEAR .
2. Check for DTCs. Refer to DTC CHECK / CLEAR .

   OK

   DTC B1244 output does not occur.

NG → See step   2 

OK → See step   5 

1. Using the Techstream, read the Data List.
   MAIN BODY
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Illumination Rate Info	Illuminance detected by automatic light control sensor/0 to 235600 lx	Illuminance value displayed	-

   OK

   Output illuminance is as shown in table above.

NG → See step   3 

OK → REPLACE MAIN BODY ECU 

Fig 1: Identifying Main Body ECU Connector Terminal

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   E2-20 (CLTB) - E2-18 (CLTE)	Engine switch on (IG)	11 to 14 V

NG → REPLACE MAIN BODY ECU 

OK: Go to next step 

Fig 2: Identifying E2 ECU Connector And F9 sensor Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the E2 ECU connector.
2. Disconnect the F9 sensor connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   E2-20 (CLTB) - F9-6 (CLTB)	Always	Below 1 Ω
   E2-19 (CLTS) - F9-5 (CLTS)
   E2-18 (CLTE) - F9-3 (CLTE)
   E2-20 (CLTB) - Body ground	Always	10 kΩ or higher
   E2-19 (CLTS) - Body ground
   E2-18 (CLTE) - Body ground

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   6