Hi! My name is Thomas and I am a new Volvo owner. I own a Tire Shop In New Orleans so I know a little about cars. If anyone has any tire questions I can help!

I bought a 2003 Volvo V70 2.5 Non Turbo Wagon for $500 that looks brand new but (there is always a catch) does not run. Sometimes it runs and sometimes it does not.

When the engine does not run the ECU will not communicate with a OBDII scanner. It simply won't scan. When it is scanable the vehicle runs and there are no engine codes but does have a no communication code when I scan the transmission.

I checked the relay and the fuses that power up the ECU and the ECU is getting power. (Fuse 3 to the vacuum pump is blown but seems unrelated my my problem. A new fuse will blow right away.)

How can I track this problem further? Are there any common ECU problems or ground loss problems to the ECU I should look for?

If I put in a used ECU to check it will it run or would the security system have to be programmed to the key? I see the ignition switch has a wire that leads back to the ECU in the wiring diagrham. Where should I go from here?

Thanks so much for all of the valuable knowledge here!

In the mean time I will keep searching some more keys words to see if anyone else had the same problem.

 

Anyone ever had this problem?

Can I swap the computer without security programming?

Thanks!!