DTC U0242: Lost Communication With Headlamp Control Module "B" [10/2017 - 09/2019]: Procedure

1. Clear the DTCs.

   Refer to DTC CHECK / CLEAR [02/2017 - 09/2019]

   Body Electrical > HL AutoLeveling > Clear DTCs 

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  2

1. Turn the ignition switch to ON.
2. Check for DTCs.

   Refer to DTC CHECK / CLEAR [02/2017 - 09/2019]

   Body Electrical > HL AutoLeveling > Trouble Codes 

   OK

   DTC U0242 is not output.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2017 - 05/2018]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [05/2018 - 09/2019] 

Result: 

NG 

See step  3

1. Disconnect the A16 headlight ECU sub-assembly LH connector.
2. Disconnect the A17 headlight ECU sub-assembly RH connector.
3. Measure the resistance according to the value(s) in the chart below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A16-20 (LINL) - A17-20 (LINL)	Always	Below 1 Ω
   A16-20 (LINL) or A17-20 (LINL) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  4

1. Replace the headlight ECU sub-assembly RH with a new or known good one.

   Refer to REMOVAL [10/2017 - 09/2019]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  5

1. Clear the DTCs.

   Refer to DTC CHECK / CLEAR [02/2017 - 09/2019]

   Body Electrical > HL AutoLeveling > Clear DTCs 

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  6

1. Turn the ignition switch to ON.
2. Check for DTCs.

   Refer to DTC CHECK / CLEAR [02/2017 - 09/2019]

   Body Electrical > HL AutoLeveling > Trouble Codes 

   OK

   DTC U0242 is not output.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

END (HEADLIGHT ECU SUB-ASSEMBLY RH WAS DEFECTIVE) 

Result: 

NG 

REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH. Refer to  REMOVAL [10/2017 - 09/2019]