Dreaded Check Engine light on after 3 weeks of Ownership

[aceinspp57]

I had those fuel trim codes, too, but then something much worse happened: I parked in the paid garage downtown, shifted it to park, maybe shut it off, but then all the PRND lights flashed on and off at once, a message saying "Service Shifter System" popped up, and it freaking locked the shifter! Found codes U1465 and U1466 with my OBD tool but they could not be reset. Panic! I'm in a paid garage, stuck in park, in a car that has no manual release out of park, with an immobilized car. I would've had to get a flatbed with dollies into the unattended garage to tow it to a dealer.
LUCKILY...I went back after 20 minutes or so, turned it on, and it shifted fine, as if nothing had happened. I got it to the dealer right away. They applied this TSB: 18-022-26 REV. D for the fuel trims and ESM (shifter) software from 68590558AF to 68590558AG, and all the problems are gone and no MIL.

Welcome to the forum. See this is your first post. Would like for you to go the the six pack introduction thread and introduce your self and tell us a little about you. Thanks later RJD

 

[CareerFirefighter]

... I got it to the dealer right away. They applied this TSB: 18-022-26 REV. D for the fuel trims and ESM (shifter) software from 68590558AF to 68590558AG, and all the problems are gone and no MIL.

So you got REV D and I got REV C. Interesting.

I wonder if a year from now there's going to be REV L, M, N O, P ...

 

[Pioneer4x457]

I had those fuel trim codes, too, but then something much worse happened: I parked in the paid garage downtown, shifted it to park, maybe shut it off, but then all the PRND lights flashed on and off at once, a message saying "Service Shifter System" popped up, and it freaking locked the shifter! Found codes U1465 and U1466 with my OBD tool but they could not be reset. Panic! I'm in a paid garage, stuck in park, in a car that has no manual release out of park, with an immobilized car. I would've had to get a flatbed with dollies into the unattended garage to tow it to a dealer.
LUCKILY...I went back after 20 minutes or so, turned it on, and it shifted fine, as if nothing had happened. I got it to the dealer right away. They applied this TSB: 18-022-26 REV. D for the fuel trims and ESM (shifter) software from 68590558AF to 68590558AG, and all the problems are gone and no MIL.

Ahh, the shifter, another issue crossover between the Daytona and Sixpack. More to come I'm sure.
One thing I've noticed when my car decides to flake out is shut it off, open the door, close the door and wait. If you look at the shifter itself, everything else will shut down, but the "P" will stay lit. Wait for that to go out after a couple minutes. Then open the door like you are getting in again normally.

 

[NewYorker9]

Very good to know...

 

[daperry2]

Well after spending two weeks late May diagnosing check engine light and various codes at the dealership with Star and TA's from Dodge involved, we seemed to have the issue reappear again at 2,300 miles. Dealership told me today to bring it back Monday for another extended stay as codes imply the previous issue has returned. They really don't know why and will contact area TA again to help with diagnosis and repair again. This is now the 4th time check engine issues have occurred with the first 3 prior to 850 miles and two months of ownership. If anyone has access to internal data, I would appreciate knowing if VIN # 2C3CDAMP3TR241855 flags as UCONNECT is having issues too. In service date was 04/03/2026. Thanks

 

[Don Keppler10]

I

Check your gas station. These need 93 Top Tier Certified in them. Probably the most common thing to trip the CEL is bad gas.

The computer and sensors really notices the bad gas if you run it hard. I just posted on this in another thread. I’ve seen it in the Wagoneer SO Hurricane with ”93 octane” that wasn’t Top Tier.

It is just as important to use top tier gas as the correct octane. Every 3,000 miles add a 20 oz bottle of Chevron Techron Concentrate Plus Fuel System Cleaner. It helps prevent carbon build up on the exhaust valves.

 

[vrax14]

https://www.toptiergas.com/ You can use their site or app. The manual specifically calls out using Top Tier Certified as recommended… so probably even more important if going to run 91 in lieu of 93… the manual says 91 is the minimum for HO version, but my SO Wagoneer only allows for 93 so that’s interesting…

A quick list of common stations generated from AI:


Most Widely Available
• Shell — nitrogen-enriched formula that cleans and prevents engine deposits
• Chevron — one of the most recognized TOP TIER brands nationwide
• Exxon / Mobil — uses “Mobil Synergy,” a blend of 9 additives including detergents, a friction modifier, and a corrosion inhibitor
• Phillips 66
• Valero
• Sinclair — 1,300+ locations across the U.S.
• Sunoco
Best Value
• Costco (Kirkland Signature gas) — TOP TIER certified and typically up to 21 cents per gallon cheaper than competitors, though membership is required

Great info thanks.

 

[daperry2]

I

It is just as important to use top tier gas as the correct octane. Every 3,000 miles add a 20 oz bottle of Chevron Techron Concentrate Plus Fuel System Cleaner. It helps prevent carbon build up on the exhaust valves.

Will check again but since day 1, never used anything but Shell 93 octane from 1 of 2 Shell stations in my area. Thanks for the fuel system cleaner suggestion.

 

[2026 Metalflake Green2]

Well after spending two weeks late May diagnosing check engine light and various codes at the dealership with Star and TA's from Dodge involved, we seemed to have the issue reappear again at 2,300 miles. Dealership told me today to bring it back Monday for another extended stay as codes imply the previous issue has returned. They really don't know why and will contact area TA again to help with diagnosis and repair again. This is now the 4th time check engine issues have occurred with the first 3 prior to 850 miles and two months of ownership. If anyone has access to internal data, I would appreciate knowing if VIN # 2C3CDAMP3TR241855 flags as UCONNECT is having issues too. In service date was 04/03/2026. Thanks

Hi Brother:

I have been there. I have Scat Pack Plus and went through numerous trips to the dealer for the first 2 months of ownership. The car appears to be stable now and hoping it stays that way. These are great looking and performing vehicles when everything works as it should, but don’t think we’re ready for prime time. Good luck with yours!

 

[baabootoo55]

I

It is just as important to use top tier gas as the correct octane. Every 3,000 miles add a 20 oz bottle of Chevron Techron Concentrate Plus Fuel System Cleaner. It helps prevent carbon build up on the exhaust valves.

Isn't this the old days? If not, have a link?

 

[daperry2]

Hi Brother:

I have been there. I have Scat Pack Plus and went through numerous trips to the dealer for the first 2 months of ownership. The car appears to be stable now and hoping it stays that way. These are great looking and performing vehicles when everything works as it should, but don’t think we’re ready for prime time. Good luck with yours!

Thanks! Will see what happens next week when they start running diagnostics again. Mine is the Scat Pack Plus too with all options except glass roof. Hopefully a new generation of mechanics with degrees in software engineering can be trained as this seems to be the future. Gone are the days when a tach, dwell meter, timing light, and a couple of wrenches usually did the trick. At least my 442 W30 restoration project is still reliable in the interim though not as quick as the Scat Pack.