Servicing Engine Soon light on

Hi everyone,

My car is a 1994 Saturn SL2 (automatic). It runs fine. Two weeks ago, the Servicing Engine Soon light turned on suddenly when I was driving and went off after several minutes. Later everything is fine, but yesterday the light turned on again when I was driving. I was a bit scared.

Does anyone know what's wrong with my car? And what do I need to do now?

I found several discussions in this forum about Check Engine light on. But first, do these two lights mean the same thing? Second, I didn't do anything to my car - I didn't replace and add anything to it. It just happened.

Your info is greatly appreciated!

Yes, Autozone will do free code reading. Since its a GM you can also pull the code yourself if there's not an Autozone nearby. You just need to jump the computer connector (should be under the dash on the driver's side) with a paper clip. If memory serves me correctly, its the 5th and 6th pins on the top row of the connector that need to be jumped with the ignition in the ON position (but not running). The SES light will flash -- count how many times. That's your error code.

Double-check this before you do it though, you ought to be able to verify exactly which pins to jump with a Google search. The code lists aren't hard to find either.

Actually I phrased that kind of badly now that I read over what I posted.

The SES light will flash but the trick is counting it right. It should flash, then pause, then flash again... so if it flashes twice, then pauses, then flashes six times, your error code is 26. If it flashes three times, pauses, then flashes once, your error code is 31... hopefully that makes more sense.

Thanks. Too bad I don't have the user mannual with me and can't find it online. I have heard about checking error code before. Hope I can figure out which pins to jump with a google search.

I'll actually be able to definitely tell you later today (Monday) once I get to my toolbox at work. I have an old packet that lists the different methods of checking the SES light. Expect to hear back from me around 3 PM EST :)

Okay, I was correct if you have the OBD-I connector, which  you _might_. To tell which one you have, take a look at the connector (usually under the driver side dash, but if you can't find it, look on the passenger side). If it is shaped like a trapezoid, it's an OBD-I. If not, then you have the old GM code connector, the ALDL.

With OBD-I, jump connectors 5 and 6 (from the left) on the top with a paper clip. Right-side-up, the connector looks something like this:

___________

The OBD-I connector is a 16-pin connector. Now, if its the ALDL connector, it should look somewhat rectangular and have 12 pins. With the ALDL, the pins you need to jump are the top two right-most pins, called A and B. Like the OBD-I connector, the ALDL should be under the driver's side. Just remember, DO NOT crank the engine with the diagnostic terminal on the ALDL grounded -- you could possibly do some costly damage to your ECM. All you need to do to check the code is turn the ignition into the ON position and jump A and B. Once you do that, the ECM will enter diagnostic mode and will display Code 12 first (one blink, pause, two blinks). Code 12 will appear three times, then any codes in the ECM will display, then Code 12 will appear again and the process will continue until you shut the car off. To clear the code, all you have to do is disconnect the negative battery cable for about 30 seconds.

It's possible (though unlikely) that your car uses OBD-II -- GM started using it on SOME models back in '94. If that's the case, the connector will look exactly like the OBD-I connector, but jumping the 5 and 6 will just cause the SES light to blink a couple times and do nothing. The only way to pull OBD-II codes is with a diagnostic reader. You can get a simple one off eBay for around $50-$60.

Once you get the code, post it here and I'll look it up for you if you can't find a code list.