DTC 5-1: LEXUS Link Communication Error: Procedure

1. Turn the power switch from ON (IG) to OFF.
2. Turn the power switch ON (IG) and wait for 10 seconds.
3. Check for the DTC again and wait for 20 seconds. Refer to DTC CHECK / CLEAR .

   OK

   DTC 5-1 is not output.

NG → See step   2 

OK → See step   3 

1. Check for DTC using the Techstream. Refer to DTC CHECK / CLEAR .

   HINT: 

   The bus buffer ECU is connected to the CAN. Check that there are no CAN communication system DTCs present.

   RESULT
   
   

   Result	Proceed to
   No DTC	A
   DTC related to CAN communication system present	B

   HINT: 

   The "U" code is a CAN communication system code.

B → See step   4 

A: Go to next step 

1. When the headlight dimmer switch is set to the low beam position, check that the hazard switch illuminates.

   OK

   Hazard switch illuminates.

   HINT: 

   The mayday ECU uses the dimmer switch signal from the main body ECU to judge if communication has stopped.

NG → See step   6 

OK → REPLACE MAYDAY ECU TOGETHER WITH MAYDAY BATTERY AND THEN PERFORM REGISTRATION