8

I'm looking to buy my first car and I went to a second hand car dealership to test drive one of their cars. I've got an OBDII fault code reader but when I wanted to plug it in the man said that in the past other people had plugged those things into cars and it had broken the car, so he refused to let me plug mine in. When asked how he just said that the lights on the dashboard lit up, he wasn't very specific about how it actually damaged it.

I'm wondering if this is a legitimate issue he might have had or if he was just not wanting me to find out about all the faults the car has.

The visual check of the car I did was fine and the tyres including the spare was fine. And when I looked though the service history of the car it all seemed fine to my extremely limited experience and there was no obvious issue with driving the car, this is the only real thing which made me wonder about how good it or the dealership might be.

Blazen
  • 181
  • 1
  • 2

2 Answers2

19

This is a legitimate cybersecurity issue due to car theft.

Immobilizers and keyless entry systems are programmed through the OBD port. With a scanner, you can simply pair a new key fob to the vehicle, come back and drive away.

Newer cars require registration and an access token from the manufacturer's server to access key and immobilizer functions, but many older cars have no such security.

A no OBD port access policy is present even in quasi-professional settings like auto auctions (see "CAN I REMOVE THE TRACKING DEVICE?").

You will either have to use a mutually trusted mechanic, ask the dealer to do a scan for you with their tool, or merely observe the CEL.

user71659
  • 643
  • 3
  • 10
17

Absolutely a red flag. If he won't let you use your OBDII scanner, then ask him to bring his out. If he believes the car has no issues, then he shouldn't fear the scanner (yours or his). If he still refuses, walk away. There are better cars and definitely better car dealerships to work with.

Pᴀᴜʟsᴛᴇʀ2
  • 165,084
  • 32
  • 259
  • 508