How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Toyota Service Your Own Question
Toyota Service
Toyota Service, Lexus and Toyota expert
Category: Lexus
Satisfied Customers: 4915
Experience:  30 + years of experience; Multiple Award Winning Svc Mgr; Just Answer Customer's Choice Award Winner
Type Your Lexus Question Here...
Toyota Service is online now
A new question is answered every 9 seconds

Lexus LS400: I have a Lexus LS 400 the engine is not communicating

Customer Question

I have a Lexus LS 400 the engine is not communicating when I used the scanner what could be wrong?
Submitted: 2 years ago.
Category: Lexus
Expert:  Toyota Service replied 2 years ago.
Hello. Welcome to Just Answer. Please allow me to assist you.There are 4 common things that will cause a scanner to not communicate with the vehicle computer:1) The scanner is incompatible with the vehicle in question2) The connection between a compatible scanner and the diagnostic port is not making good contact3) There are blown fuses in the EFI/Computer system that power up the computer4) There is insufficient ground connections at the computer or the battery5) The computer in the car has an internal failure which prevents communication The recommendation here would be to see of your scanner works on a comparable vehicle. If not, get another scanner If it does, and all of the fuses and grounds are good, it might be time to think about a replacement computer in the vehicle. Thanks for choosing Just Answer. It was a pleasure to assist you. If you have any questions, please feel free to reply. If you are satisfied with my input, a positive rating would be greatly appreciated. Thanks in advance.
Customer: replied 2 years ago.
l have rebuilt the computer but the scanner is still not communicfating
Expert:  Toyota Service replied 2 years ago.
I would try your scanner in a compatible vehicle. Perhaps the scanner is the problem. If the scanner does not communicate, there is either a problem with the DLC2 interface connection, the wiring between the DLC2 connection and the computer, or the computer itself is faulty.