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1995 corsica

i have a 95 corsica and the car runs quiet and smooth but only when i drive at hi speed in cruise control when i tap the brake to turn off the cruise control or even when i am not using cruise when i tap the brake to begin slowing down the engine light comes on but it never happens in town only at 55 or higher speeds anybody have any ideas i have taken it to autozone and they gave me one of those metal keys for the plug but no good can anybody help or no why the light comes on?

How about another attempt to get the codes read?

Have no idea what you mean about a metal key for the plug

Did Auto Zone say they couldn’t get codes, did they give your a direction to take in getting your trouble codes?

its amazing nobody has herd of this key from autozone you have to buy the code reader on 95 or older the key i am talking about looks just like a key autozone gave it to me but check engine light does not flash though.do you thin it could be the speed sensor?

OKAY! I read this about 10 times trying to understand what this key was, and I get it now. GM cars’ ALDL connector can be jumpered so that the Check Engine Light flashes out the codes that are stored.

Unfortunately! You are falling victim to what has been dubbed “OBD 1.5”. GM transitioned from OBD to OBD II in 1994 and 1995 (http://en.wikipedia.org/wiki/OBD-II#OBD_1.5) and this left a few cars out in the cold.

The short version is: you HAVE TO USE A SCAN TOOL on these vehicles. They will not flash out the codes like the old OBD cars do. If your Autozone can’t figure out that little nugget (and they can’t really be blamed, those guys aren’t mechanics) you really should consider taking it to the dealer to just have the codes read.

I imagine this “key” is a jumper so you can put your car into diagnostic mode and count some light flashes, didn’t Auto Zone give you any instructions on how to use the key?

Another way to read the codes in your car (the way the dealer would do it) is with the TECH1 scanner(for OBD1 cars) if you can’t get your car to flash codes you may have to get someone with a TECH1 or a comparable scanner to do it (this shouldn’t be hard)