The dreaded and mysterious "Engine Light" is on!
Thread Starter
5 Year Member
Joined: Mar 2009
Posts: 1,322
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From: The Great Midwest, aka, Flyover Country
The dreaded and mysterious "Engine Light" is on!
So...2018 SCab XL 4x4 with the 3.5TT EB with 54K miles, regularly serviced, always garaged, no vermin infestation. Light showed up a day ago with zero outward signs of weirdness from the truck in terms of operation--no engine glitches, no stumbling, no poor shifting, etc. I checked the capless fuel fill and it looks like it's seated, visually anyway. Here's the question: should I make a trip to get the code(s) read at an auto parts store? Or izzat waste of time? Can I get any additional specific information by going into the engineering mode and scrolling through the long list of parameters? Or should I do a battery disconnect to bleed the charge off the ECU/BCM and reconnect after 15 minutes to see if the code is gone?
As an add, the battery is less than a year old and gets a regular top-off charge every couple of weeks. No reason to believe the battery is suspect.
Thx for the help!
As an add, the battery is less than a year old and gets a regular top-off charge every couple of weeks. No reason to believe the battery is suspect.
Thx for the help!
Last edited by icantdrive55; Feb 18, 2026 at 10:46 AM.
Thread Starter
5 Year Member
Joined: Mar 2009
Posts: 1,322
Likes: 532
From: The Great Midwest, aka, Flyover Country
OK. Much ado about nothing....or perhaps a "non-event"....maybe?
The light has been on every key cycle for the last 3-4 days. Went out to the garage to head out to have the code(s) read and...the light didn't come on at startup. Called the shop that I use for repair and they said if the light wasn't on they couldn't grab any fault codes to read. What comes to mind is that on my way home last night, I stopped and filled the tank. Gonna throw out a guess that the act of sticking the nozzle into the filler neck "fixed" whatever potential misalignment of the spring-loaded seal had occurred, and it took a couple of key-on-off cycles to clear. So, some sort of electronic fart by the one of the myriad of sensors on these rolling computers. Should'a gone back to get my PhD in modern coding.
The light has been on every key cycle for the last 3-4 days. Went out to the garage to head out to have the code(s) read and...the light didn't come on at startup. Called the shop that I use for repair and they said if the light wasn't on they couldn't grab any fault codes to read. What comes to mind is that on my way home last night, I stopped and filled the tank. Gonna throw out a guess that the act of sticking the nozzle into the filler neck "fixed" whatever potential misalignment of the spring-loaded seal had occurred, and it took a couple of key-on-off cycles to clear. So, some sort of electronic fart by the one of the myriad of sensors on these rolling computers. Should'a gone back to get my PhD in modern coding.
5 Year Member
Joined: Mar 2015
Posts: 2,456
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From: Anchorage, AK
OK. Much ado about nothing....or perhaps a "non-event"....maybe?
The light has been on every key cycle for the last 3-4 days. Went out to the garage to head out to have the code(s) read and...the light didn't come on at startup. Called the shop that I use for repair and they said if the light wasn't on they couldn't grab any fault codes to read. What comes to mind is that on my way home last night, I stopped and filled the tank. Gonna throw out a guess that the act of sticking the nozzle into the filler neck "fixed" whatever potential misalignment of the spring-loaded seal had occurred, and it took a couple of key-on-off cycles to clear. So, some sort of electronic fart by the one of the myriad of sensors on these rolling computers. Should'a gone back to get my PhD in modern coding.
The light has been on every key cycle for the last 3-4 days. Went out to the garage to head out to have the code(s) read and...the light didn't come on at startup. Called the shop that I use for repair and they said if the light wasn't on they couldn't grab any fault codes to read. What comes to mind is that on my way home last night, I stopped and filled the tank. Gonna throw out a guess that the act of sticking the nozzle into the filler neck "fixed" whatever potential misalignment of the spring-loaded seal had occurred, and it took a couple of key-on-off cycles to clear. So, some sort of electronic fart by the one of the myriad of sensors on these rolling computers. Should'a gone back to get my PhD in modern coding.
Thread Starter
5 Year Member
Joined: Mar 2009
Posts: 1,322
Likes: 532
From: The Great Midwest, aka, Flyover Country
Guess that's possible. At this point, with no symptoms showing up and no light illuminated, I think just leave well enough alone. If it happens again, I'll investigate more thoroughly.
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Captain of Industry
Joined: Nov 2011
Posts: 4,614
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From: Arklahoma
It's faily common for a Check Engine light to come on and then go off after a few engine cycles or the next time you gas up. Probably nothing to worry about unless it happens again. I had a Grand Cherokee that would show the Check Engine light when I drove it in the mountains above about 8000 feet elevation. A day or two after returning to lower elevation it would go off and stay off until the next mountain trip.
