# Check Engine Light came on while driving **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** sonoma, gmc\ **Created:** [February 10, 2020, 5:33am UTC](https://community.cartalk.com/t/check-engine-light-came-on-while-driving/158239 "2020-02-10T05:33:28Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![Mr\_R](https://avatars.discourse-cdn.com/v4/letter/m/7c8e57/32.png) [@Mr\_R](https://community.cartalk.com/u/Mr_R)\ **Post date:** [February 10, 2020, 5:33am UTC](https://community.cartalk.com/t/check-engine-light-came-on-while-driving/158239/1 "2020-02-10T05:33:29Z")
While driving on the freeway my “service engine soon” light came on. The vehicle runs fine, idles fine, starts normally but the light stays on. So what’s the problem? Oxygen sensor? or something else? Vehicle is 2002 GMC Sonoma pickup w/4.3 liter V-6 motor and 72,000 miles. ---
**Author:** ![SteveCBT](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/stevecbt/32/3192_2.png) [@SteveCBT](https://community.cartalk.com/u/SteveCBT)\ **Post date:** [February 10, 2020, 11:03am UTC](https://community.cartalk.com/t/check-engine-light-came-on-while-driving/158239/2 "2020-02-10T11:03:24Z")
If it is truly service engine soon you may need an oil change. If it is the check engine light, stop by an auto parts store, frequently (except CA) they will read the codes for free. Post the code here, it will look like Px123 ---
**Author:** ![Purebred](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/purebred/32/46796_2.png) [@Purebred](https://community.cartalk.com/u/Purebred)\ **Post date:** [February 10, 2020, 11:29am UTC](https://community.cartalk.com/t/check-engine-light-came-on-while-driving/158239/3 "2020-02-10T11:29:33Z")
If you don’t have an owners manual, most likely it is available online. ---
**Author:** ![MikeInNH](https://avatars.discourse-cdn.com/v4/letter/m/a587f6/32.png) [@MikeInNH](https://community.cartalk.com/u/MikeInNH)\ **Post date:** [February 10, 2020, 3:40pm UTC](https://community.cartalk.com/t/check-engine-light-came-on-while-driving/158239/4 "2020-02-10T15:40:05Z")
> [@Mr\_R](#): > > While driving on the freeway my “service engine soon” light came on. Service engine soon usually means some preventative maintenance item needs to be performed. This should all be spelled out in the owners manual. ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [February 10, 2020, 4:48pm UTC](https://community.cartalk.com/t/check-engine-light-came-on-while-driving/158239/5 "2020-02-10T16:48:34Z")
> [@MikeInNH](#): > > Service engine soon usually means some preventative maintenance item needs to be performed > **[Check Engine Light or Service Engine Soon Repair in Morristown, NJ](https://www.shadetreegarage.com/check-engine-light/)** > > So your Check Engine Light or a Service Engine Soon Light is on. What does it mean? How fast do you need to take care of it? Shade Tree Garage in Morristown, NJ can help. Tester ---
**Author:** ![MikeInNH](https://avatars.discourse-cdn.com/v4/letter/m/a587f6/32.png) [@MikeInNH](https://community.cartalk.com/u/MikeInNH)\ **Post date:** [February 10, 2020, 6:58pm UTC](https://community.cartalk.com/t/check-engine-light-came-on-while-driving/158239/6 "2020-02-10T18:58:48Z")
That’s not the way Toyota does it on my Highlander. There’s a Check Engine message and a Service Engine soon message. Check Engine - ECU error. Service Engine Soon - Every 5k miles as a reminder to either do an oil change or tire rotation and oil change. ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [February 10, 2020, 7:02pm UTC](https://community.cartalk.com/t/check-engine-light-came-on-while-driving/158239/7 "2020-02-10T19:02:44Z")
We’re not talking about your Highlander, now are we? Tester ---
**Author:** ![MikeInNH](https://avatars.discourse-cdn.com/v4/letter/m/a587f6/32.png) [@MikeInNH](https://community.cartalk.com/u/MikeInNH)\ **Post date:** [February 10, 2020, 7:07pm UTC](https://community.cartalk.com/t/check-engine-light-came-on-while-driving/158239/8 "2020-02-10T19:07:31Z")
And the link you provided isn’t for GM now is it? ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [February 10, 2020, 7:16pm UTC](https://community.cartalk.com/t/check-engine-light-came-on-while-driving/158239/9 "2020-02-10T19:16:15Z")
It’s the same as a CEL, per the owners manual: "This system is called OBD II (On-Board Diagnostics-Second Generation) and is intended to assure that emissions are at acceptable levels for the life of the vehicle, helping to produce a cleaner environment. The SERVICE ENGINE SOON [US] or CHECK ENGINE [Canada] light comes on to indicate that there is a problem and service is required. "