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Service engine light

I looked at a 2001 Chevy Cavalier today that is for sale. Instead of a check engine light that stays on, it has a service engine light with a picture of a little wrench. The check light comes on with the key before starting, but goes right off. The wrench light stays on. I’ve never seen a light like this. What does it tell me? How do I fix its issue and turn it off? There is no owner’s manual, or I probably wouldn’t need to ask here.

The service engine soon light is displayed, usually, for maintenance which is past due, such as oil change interval.
You need the Owner’s Manual. It has information which may not be available ANYWHERE else.

Let’s be realistic. I’m not likely to buy a manual off of ebay for a car I MIGHT buy. Figure by the time it would get here, the car would probably be sold to someone else. Then I’d be stuck with a manual for a car I’m not likely to ever own.

Did you try some simple internet searching for online manuals? I have found free full-text owner’s manuals online (last one I recall was for a Ford and I think it came via Ford).

Or someone here might have the specific knowledge of that light.

Or you can probably find discussion boards dedicated to Chevy and even Cavaliers

I’m afraid the online manual won’t help you much. Here is a “cut and paste” of what it says. In other words, come in and spend money. Maybe that’s why it’s for sale.

Service Vehicle Soon Light

This light will come on briefly when you turn on the ignition. It will stay on or come on if it detects a problem on the vehicle. If this happens, see your dealer?s service department as soon as possible.

Here’s the owners manual for 2001 Cavalier.


I believe the wrench light indicates some sort of maintenance needs to be done.

Time to have the car owner get the codes read and service the vehicle before you proceed with a purchase.

The SERVICE ENGINE SOON light (a wrench symbol) is NOT the same thing as the CHECK ENGINE SOON light (an engine symbol). The owner’s manual, which Tester shows a link to, does NOT tell what will cause the SES light to come on. It just tells you to, “see your dealer for service”.
Only the CHECK ENGINE SOON light (an engine symbol) will hava a scanable DTC trouble code, such as P0300.

Ahh, and therein lies the point of the question. What does the light tell me? Can I find out without taking the guy’s car to the dealer? I’m not sure I’m willing to do that as it’s an as-is deal. He’s not willing to fix anything.

A quick Google search leads me to believe this is a trouble light for the BCM (Body Control Module), and probably has a proprietary code system that only the dealer has. To find out what the problem is, a trip to the dealer may be your only choice. This is different from the OBD-II system that is mandated for the engine control module (ECM).

Try this technique, to turn off the wrench icon light, turn the ignition key to RUN (engine off); Depress the gas pedal to the floor three times (slowly, within 5 seconds)and wait a few seconds for the wrench icon to go off; Turn key OFF.

I tried that, thinking it might be like the “oil change” light. It stayed on.

You ask what the light is telling you.

It’s telling you the vahicle has some unknown condition, whether it’s neglect or a fault happening. It’s telling you that if you don’t take this as a warning and look at other vehicles instead, you can only blame yourself should you discover a serious problem after the purchase.

Keep looking. There are other cars out there.

The cause of the lit WRENCH ICON could be as simple as a burned out bulb! Look for an unlit light on the dash, gear shift indicator, power window switch, and courtesy lights. Turn the interior lights dimmer switch to different positions, and check the interior lights. If any are burned out, replace them.
Only a GM TECH 2 scan tool (or, equivalent) can scan the BCM (Body Control Module) for the trouble codes which could turn on the WRENCH ICON light. Changing all burned out interior lights may turn the WRENCH ICON off. Try it.
The BCM sends power (12? volts) to: the dimmer switch, dash lights, gear shift indicator lights, power window switch light, interior lights, courtesy lights.
The wiring diagrams are at public library Web site ARRC (Auto Repair Research Center). Once at ARRC, input vehicle data, and look under: WIRING DIAGRAMS > INTERIOR LIGHTS. The wiring diagram shows the lights which the BCM provides power to.
If any reader visits the ARRC site, please tell us. After dozens of referrals to the ARRC site, only ONE person has said they did visit there.