How do the scanners at the dealer work?

Everyone knows you can go to Autozone, shucks auto stores and get your "codes" read.

The dealers have better ones that tell you more then that. I was wondering what it shows. How much more does it show? Someone told me there are codes it reads that the auto parts stores don't.

If there is codes stored, how come the other ones can't read them?

Can someone explane what the scanners at the dealers are like?

I'm havening some more problems with my car and can get the dealer to read the codes for $77.

What are the limitations of a dealer code reader?

If I go to shucks and have them clear my codes, does that clear the ones it doesn't read?

Thank you,
Chris.

I know just enough to be dangerous. I've never worked as a mechanic and don't have firsthand knowledge of GM dealership service departments other than as a customer. But, as far as I can tell, GM dealers use Vetronix's Tech 2 scanner to read all GM cars from 1992 to now. They can read ABS codes, transmission codes, and lots of other detailed information that the simple code readers can't. Is it worth having done? If you have a problem with your car and you take it to them, I imagine they will run codes on it as a first step. If they find the problem quickly via the scanner and then advise you of the problem, saving you lots of time and parts swapping trying to guess your problem, then yes, it is worth it. If your car has no meaningful error codes set, then perhaps it is not worth it. I think it is a great idea to pay for this especially if they will give you a detailed report of what they find. This information could be helpful down the line as problems pop up. Or it could be helpful now as you find there may be several systems not performing at their peak.

The scanners are not readily available for sale to non-mechanics. They are very expensive if you can find one (several thousand dollars).

I have a cheap scanner, ($200.00) and it reads codes as long as the Service Engine light come on, and a code is stored. It has been a reasonably useful tool for me, (four GMs in the family) BEFORE I go to the dealer. Anyway, my question is, are there codes stored in a GM vehicle that do not trigger the Service Engine light? Thanks.

The Tech II also allows you to do so much more--like energize relays on command- and exercise solenoids and the like-- as well as gives you all the current data readings of all the various systems- like egr position, throttle position in both voltage and percentage- and all types of status "on" and "off" signals. It also does all the "body" codes- like HVAC doors and actuators- and remote keyless programming. It can also record events as in snapshots and data logging- to try to find out what is wrong-- I have used them often- and even had one for awhile until one of my mechanics was laid off and stole it-- but that's another story. I would buy another in a heartbeat- but they run about $3200- and have to be updated about avery six months- with downloads from GM- to keep up with current changes and new models......

Thanks for the replys.

I asked if they hook up the scanner to check it out, could it also tell me why my Curse Control doesn't work? (Cruse is not the problem I'm looking at right now, just wondering if that problem could be included with the info they get). They said No.

If the dealer can get "body" codes and all the others, why can't it see the electric stuff from the cruse?

I'm leaning strongly towards taking it in.
Chris.

Thanks for the replys.

I asked if they hook up the scanner to check it out, could it also tell me why my Curse Control doesn't work? (Cruse is not the problem I'm looking at right now, just wondering if that problem could be included with the info they get). They said No.

If the dealer can get "body" codes and all the others, why can't it see the electric stuff from the cruse?

I'm leaning strongly towards taking it in.
Chris.

My guess is that your cruise perhaps does not work due to a mechanical failure of your servo, a vacuum leak, or a problem with the wiring. I don't think scanners are meant to trace wires. You can do that with much simpler tools, such as a multimeter.