2002 Jeep GC Engine light is on

Overpriced useless Jeep that should be made by Ford instead? ;)

Brian Foster did pass the time by typing:

Loose nut behind wheel?

gas cap, or Oxygen sensor ?

"L.W. ("ßill") Hughes III" a écrit dans le message de news: snipped-for-privacy@cox.net...

And the winner is!!!

Excellent guess. That happened the first week I owned the vehicle. This time they said my gas cap was shot so I needed a new one. Gas cap $17.11 Diagnosis & labor $93.50

They also detected a "misfire" on the computer so they did a "3M Complete fuel system maintenance" $42.44 worth of parts $140 labor

Throw in another $$17.70 for shop supplies and an EPA fee.

$317.12 No more engine lite and car is running better.

They also wanted to rotate and balance my tires (I declined) and they wanted to put new hood struts on (I also declined)

This is a 5 star dealer that is owned by Pensky.

You could have saved yourself $93.50 on the diagnosis, and found the misfire on your own if you had a OBDII Code Reader and a list of codes. Here is the list,

You can get the Code Reader on eBay, the nice ones run about 90 bucks, the Really Nice ones run to about $150. This one repair would have covered the cost of the reader, the next repair could be free.

Alternate Plan B, go down to your local auto parts store. They will let you check out a code reader, sort of like how a library lets you check out a book. You could do this diagnostic and repair at home for free. Well, you would still have a parts cost, but I know for a fact that a gas cap doesn't cost $17.

Sorry for the bad news.

PS The 3M Complete Fuel System service is stuff in a can that they pour into the gas tank.

That's pretty good. Are these code readers vehicle specific or will a code reader work on a Jeep, GMC, Ford, etc...?

Thanks

Brian Foster did pass the time by typing:

OBDII is a standard on most all vehicles.

If my 93 had OBDII I'd probably be thinking about the datalogger and the code reader. However, the model shown there will even work on older OBDI/SCI systems.

Actually I may just order this for my ZJ since it will work on the newer car as well.... there goes more money.

No, they are not specific. That is the beauty of OBD II. When they - whomever "they" are - came up with OBD, each maker had their own way of doing it. It became clear that the consumer would be screwed if all cars were not built to the same spec., it was also clear that a mechanic would be burdened with an unmanagable task of keep all of the codes and readers current. So, OBD II was developed, and is required on all vehicles built after 1996. Presumably, care before that have OBD I, and the means of pulling codes on these years is dependent upon the scheme the car maker built into the system.

There are more codes than some cars need, but they will simply not be able to throw one of these. For example, let's say that Code P0440 meant that X was not working right. Your car hasn't got the X Feature, so it wouold never throw this code. But all cars that have the feature will throw the same code when whatever X means isn't working right. (It just happens that P0440 is a fault in the Evaporative Emissions System, so all cars have the ability to throw this code.)

OBD II specifies that the connector to plug into is a certain type, and is located in a specific place - this is under the dashboard in the vicinity of your left leg (in a USA car, left hand drive). The connector is easy to find, and there can be no requirement to remove any covers to gain access to it. I gotta back track on the cover part, but the connector MUST be easy to find after removing any cover that might exist in the area where your feet belong while driving. The point is, the connector is readibly accessable and easily identifiable.

If I was running a Service Department at a new car dealership, I would have the Service Writer plug in the code reader to pull the codes, and enter that information on the service ticket. If the code was one that could be caused by the owner/operator (the P0440 code comes from leaving the gas cap loose or off), I would have the service writer send the car home with the owner, and not charge to pull or clear the code. There are several codes that can come from operator error, and will not return once the error is corrected, and no parts are needed to correct the error.

However, there is still allowances for extra Manufacturer specific codes in ODB II.

Dave Milne, Scotland '91 Grand Wagoneer, '99 TJ

That's true, but if your car won't produce them, it makes no difference. Actually, even if you car does make them, the code number and a description of the fault is available if you have the correct code reader.

The MFG specific codes are for unique features that one manufacturer might have. If another manufacturer also employs a particular feature, then the code is no longer unique. The link I posted with the codes assigned to date shows some that are unique, and to whom they are assigned.

In any case, the same hardware is used to extract and reset the codes, only the codes themselves are subject to a unique quality.