Headlight ECU RH Communication Stop Mode [10/2022 - ]: Procedure

1. Disconnect the cable from the negative (-) auxiliary battery terminal.
2. Disconnect the A44 headlight ECU sub-assembly RH connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A44-24 (CANH) - A44-23 (CANL)	Cable disconnected from negative (-) auxiliary battery terminal	54 to 69 Ω

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE CAN BRANCH LINES OR CONNECTOR (HEADLIGHT ECU SUB-ASSEMBLY RH) 

Result: 

OK 

See step  2

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A44-12 (GND) - Body ground	Cable disconnected from negative (-) auxiliary battery terminal	Below 1 Ω

2. Reconnect the cable to the negative (-) auxiliary battery terminal.
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A44-6 (IGR) - Body ground	Ignition switch ON	11 to 14 V

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  3

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A44-13 (ECUB) - Body ground	Ignition switch ON	9.5 to 14 V

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE HEADLIGHT ECU SUB-ASSEMBLY RH. Refer to  REMOVAL [10/2022 - ] 

Result: 

NG 

See step  4

1. Disconnect the A74 semiconductor power integration ECU connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A74-2 (L) - A44-13 (ECUB)	Cable disconnected from negative (-) auxiliary battery terminal	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE SEMICONDUCTOR POWER INTEGRATION ECU. Refer to  REMOVAL [10/2022 - 08/2023]  , or refer to  REMOVAL [08/2023 - ] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR