OBD When Buying a Car

[Spinal]

I had an interesting one today.

I turned up to view a car I was considering bidding on, and as always asked for permission to plug an OBD reader in to check for fault codes.

The seller refused this, without providing a reason. Needless to say, I walked away; but it made me curious.

How many people would turn away/down a buyer with an OBD reader? Or as a buyer, do you usually check for fault codes or hope for the best?

M.

 

[whitenemesis]

Was the seller private or trade? MB?

 

[KillerHERTZ]

The reason might not that he is trying to hide somthing, but the fact that you might be to much hassle/grief for him to deal with. eg, if you start listing error codes and pointing out X&Y need changing, this and that needs fixing. (not aimed directly at you by the way!)

Where as the next buyer might take it for a test drive and buy it no problems.

 

[tron]

I have seen trade sellers refuse to allow obd to be used prior to sale. I would walk away. There are always more cars.

 

[prprandall51]

Considering that the papers regularly carry stories about how an extra key for the car is programmed by thieves simply tapping into the OBD port, I am not surprised that a seller would refuse you access to the port. I wouldn't let anyone plug anything into my car.

I believe BMW owners have a known fix whereby they move the OBD port back up behind the dash and fit a false one to prevent this type of theft.

 

[markjay]

As above.

Additionally a non-technical person might not fully understand what you are trying to do and will be concerned that you might somehow damage the car.

If it was a trade seller, I would ask him to connect an ODB scanned in your presence and scan the car for fault codes.

 

[Spinal]

Pseudo-trade seller (i.e. a trade seller listing the trade-in cars on eBay - perfect source for cheap cars to do charity rallies in. I help organize the White Hat Rally, which raises ~£50k a year for Barnardos)

Fully agree on the walk-away option on my side, though I didn't consider the reprogram a key aspect. It does make sense from that side for cars that are vulnerable to that (only BMW from what I know of?). Thanks though, made me see something I hadn't taken into account!

M.

 

[M12MKD]

Depends on the sellers knowledge of cars.

Me? I was happy to let the guy attached the computer to my car but then I've the same system and scanned it before the guy came so I knew what he result would return.

But best to walk away from it, with cars now days it's really like saying "no you cannot open the bonnet", he's loss your gain most likely!

Also like above as a sell you also have to be weary of scams so I kinda understand this reaction too.

Sad fact is like most thing the honest people out there get tar'd with the same brush!

 

[mersum1es]

As above.

Additionally a non-technical person might not fully understand what you are trying to do and will be concerned that you might somehow damage the car.

If it was a trade seller, I would ask him to connect an ODB scanned in your presence and scan the car for fault codes.

+1, not damage but they just don't know that MB diagnostic cannot be used to stole the car later...

...and also like another above, they do not like that you'll announce that car is actually been a taxi, mileage is rigged, and couple of injectors need changing

Most bigger dealers are also providing service, you may ask then to use OBD scanner of their own?

 

[E270 Owner]

There's code readers and handheld/laptop software programmers.

Both can potentially damage the cars canbus system and related ecu's, and lock the keys out of the immobilizer system.

I wouldn't let just any one plug a scanner/reader/programmer into a car I was selling.

As mentioned above most "dealers" have their own OBD tools.

 

[Mrhanky]

I have been asked this a couple of times I the past from potential buyers. I did not let them plug their reader in. Instead I offered to plug my own in and show them the result.

Both times I pointed out it would be best to test after the test drive as I could have simply cleared any stored codes. Neither of the people had thought of this and I very much got the impression they had only asked about the reader as someone said it was a good thing to do.

When I showed them the reader results, neither person seemed to know what they where looking at.

 

[MercedesDriver]

I would never ask seller something like this and to be honest I would never allow a buyer to attach any equipment he might have. I just find it too risky. Instead it would be much better and really appropriate asking for an independent service check at local MB or specialist. After all if someone is planning to spend few thousands, 100 pounds up doesn't make a difference.

 

[MCFastybloke]

I don't have a machine, but would ask if we could go to a dealer or indy and have them read the codes at my expense,
This happended when I sold my 997 and the buyer had it boroscoped at the same time, tech pulled out the scope from cyl 2 and the metal shroud from the end stayed in the bore, 4.30 Friday evening,buyer from Newcastle standing in a unit in Brighouse,the technician,apprentice and both partners all looking at the end of this boroscope minus the shroud.

 

[danch]

Have done this on my last 3 BMW purchases before going Merc & found faults on all generally Lambda sensor/glow plug related & each time had agreed money taken off the price to cover repair.

 

[Spinal]

Interesting how many people wouldn't let a buy check error codes. I guess I've just been lucky so far, I've brought an OBD reader to every car I've looked at bar one in the last couple of years.

The only one I didn't check first I bought from someone on here whom I trusted fully.

I wouldn't touch a car if the seller wouldn't let me run an scan nowadays unless I fully trusted them... I would be happy with them using their own scanning tool, but either way I would need to see the fault codes.

M.

 

[E270 Owner]

Put it this way, if it was your car you were selling say @ £20,000
would you allow Joe public to come along and plug in a Chinese copy e-bay special OBDII reader into your 20k cars OBDII socket ??

Reading you post it seems you would........