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.

   OK

   DTC 5-1 is not output.

OK → CLEAR HISTORIC DTC 

NG: Go to next step 

1. Check for DTC using the Techstream.

   HINT: 

   The mayday ECU is connected to the BEAN. Check that there are no multiplex communication system DTCs present.

   RESULT
   
   

   Result	Proceed to
   No DTC	A
   Related to multiplex communication system	B

B → GO TO MULTIPLEX COMMUNICATION SYSTEM 

A: Go to next step 

1. When the headlight dimmer switch is set to the low beam position, check that the combination meter indicator dims.

   HINT: 

   The mayday ECU uses the BEAN communication stop judgment to check for the dim signal from the cowl side junction block RH (main body ECU RH).

   OK

   Combination meter indicator dims.

NG → GO TO LIGHTING SYSTEM 

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