"Service engine Soon" vs "Check Engine"

[Robertwav1]

I didn't realize until recently that we now have to deal with two diagnostic lights. Guess I'm a little behind here. Here is some info I found in case anyone might be interested. By the way this is a 2000 impala I have recently worked on....no error codes using auto tap, no "check engine light" just an annoying "Service Engine Soon" popping up every once in a while. Chevy is very vague about this, their response, if it's not lit now don't worry about it. Anyway, in an ongoing investigation;

A Yellow Warning light, (Usually a Service engine soon light) indicates "Proceed with caution." The onboard computer system has indicated a potential problem and is alerting the driver. This computer system resets and re-tests all sensors and indicators each time the car is started. The computer system is capable of correcting some minor abnormalities, but if the light continues to come on after multiple car starts, it is probably sensing something that would imply a visit to the diagnostic mechanic is in order.

Some common things that may cause a yellow light (Service engine soon light) to come on, but will probably require an experienced technician to diagnose are:

• anti-lock brake systems
• safety restraint systems, such as air bags
• emissions components
• computer-related problems, such as faulty sensors

If you are driving your car and a yellow light comes on, ask yourself these questions:

1. Did you notice problems when starting the car? (slower to start than normal..etc.)

2. Have you noticed a decrease in fuel mileage recently?

3. What is the over-all running condition of the car? Is the engine misfiring or not performing like normal? Are there any new noises from under the hood? Turn off the radio and listen closely as you drive the car.

4. Do you notice any odors, such as a rotten egg smell, or see visible smoke from the tail-pipe or from under the hood?

Make sure to note the exact location and wording of the light that has been coming on, because Murphy's Law dictates that the light will suddenly not come on when you take it in to the repair shop.

In some cars, "engine" is the more serious red light, whereas others use "check engine light," which is a yellow caution light. If the mechanic thinks you are seeing a yellow "check engine light," and your car is indicating a red "engine" danger light, this could be a costly mistake for both of you. Why? You could be having a serious over heating problem and the mechanic is assuming you are having a less serious caution light illuminating. The mechanic then might give you the "green light" (no pun intended) to proceed with your out of town road trip with the kids. Yikes!

Start the car, and point to the light to ensure good communication of the problem. Intermittent dash warning lights can be a pain and hard to diagnose! Diagnosing the problem in some cases will require the light to be on while the mechanic performs the diagnostic test. If the light is not on when you bring the car to the shop, you might be wasting your time and the mechanic's.

[richtazz]

"check engine light" and "service engine soon light" are different names for the same animal. Since car manufacturers can no longer use words on warning lights in our "global" economy, they have to use symbols, which can be confusing as to what problem they are indicating.

[Robertwav1]

Originally Posted by richtazz

"check engine light" and "service engine soon light" are different names for the same animal. Since car manufacturers can no longer use words on warning lights in our "global" economy, they have to use symbols, which can be confusing as to what problem they are indicating.

I have thought this also but now....I have the latest autotap software and it's compliant with the ODB3 systems that are due in 2008. The "service engine soon" light does not record an error like the "Check Engine" light. My software shows no codes at all and the "Check Engine" light is green which means "no diag codes present". I was a little taken back by this since I have used this software with great success. Now.....something is going on and I have no means of finding out what...I kinda think that's exactly what they want. What's next? ODB3 is "big brother" to me. They are going to monitor your car via satellite and fine you if the emmissions system is not fixed in a certain amount of time.

[richtazz]

Is the light you're referring to on the instrument cluster or in the information center? You car is standard OBD-II diagnostics (similar to my Grand Prix) and I know of nothing like you describe on GM W-bodies. I'm not saying it isn't there, as I don't own an Impala, but I've never heard of what you describe.

['97ventureowner]

Here's an interesting read on the possible implementation of an OBD III system starting in California. Talk about "Big Brother"! http://www.asashop.org/autoinc/may/obd_iii_new.cfm

[Robertwav1]

Originally Posted by richtazz

Is the light you're referring to on the instrument cluster or in the information center? You car is standard OBD-II diagnostics (similar to my Grand Prix) and I know of nothing like you describe on GM W-bodies. I'm not saying it isn't there, as I don't own an Impala, but I've never heard of what you describe.

Yes...it's on the information center to the left of where the "Check Engine light" is. It's the LCD screen bout 1.5" x 1.5", the same screen that's lets you know about the oil change. This light lit 4 times but it goes out and has not come back on as of yet. It's actually an in-law's car and I'm gonna find out tonight how this week went as far as the light's status. I'm still looking into this and the more I find out....I will post. If anyone can shine any light on this subject to clarify things that would be great!

[Robertwav1]

Originally Posted by '97ventureowner

Here's an interesting read on the possible implementation of an OBD III system starting in California. Talk about "Big Brother"! http://www.asashop.org/autoinc/may/obd_iii_new.cfm

Good article! I hope it never comes to be....at least not in my lifetime. What worries me now is the fact that these politicians are going after stuff that's legal.....guess they gave up on the illegal stuff!