Ford Mustang Forum banner
1 - 12 of 12 Posts

·
Registered
2019 mustang gt premium
Joined
·
10 Posts
Discussion Starter · #1 ·
Hello all, first off I have a manual 2019 Mustang GT with a JLT CAI (oiled filter), kooks 1 7/8 long tubes, and a Corsa extreme catback active exhaust. Car only has 14,500mi with fully synthetic oil changes every 3k miles. The car is tuned by Lund for 93. When I WOT either in 2nd or 3rd gear from 3200rpm, the car throws a wrench light and goes limp when it reaches around 4200rpm. I used my ngauge to scan for DTCs but nothing shows up. I’ve cleaned the TB (stock) and MAF with their respective cleaners but that didn’t help. I’ve sent data logs to Lund before the wrench light pops up and when the wrench light is on but they couldn’t find anything wrong with the tune. All bolts are tightened under the car, all hoses are secured on the CAI. I wanted to try everything before I take it into Ford just in case it’s an easy fix I’m just overlooking and I’d rather not pay $100 for something easy. You guys have any suggestions?
 

·
Super Moderator
Joined
·
3,840 Posts
Turn off your AdvanceTrac/Traction Control and see if that helps. I have to keep mine turned off for spirited driving. For me, the tires break-loose on WOT and cause a wrench 🔧 light. Also driving on gravel roads can cause this too. Disabling this 100% eliminates the issue for me.

In my case, it’s caused by A-Symmetrical wheel speeds causing the computer to think I’ve lost control.
 

·
Registered
2019 mustang gt premium
Joined
·
10 Posts
Discussion Starter · #3 ·
Turn off your AdvanceTrac/Traction Control and see if that helps. I have to keep mine turned off for spirited driving. For me, the tires break-loose on WOT and cause a wrench 🔧 light. Also driving on gravel roads can cause this too. This 100% eliminates the issue for me.
I usually have my car in track mode which turns off traction control and I’m assuming it also turns off advancetrac but the wrench pops up in all modes. I just don’t understand how the wrench light could pop up and not throw any codes. Could there be a hidden code that can only be detected by certain scanners?
 

·
Super Moderator
Joined
·
3,840 Posts
I just don’t understand how the wrench light could pop up and not throw any codes.
Yeah, it won’t throw a regular code in most cases. A bad wheel-speed sensor or wiring issue can do this too. You may need to take it to a dealership to diagnose, but expect some resistance and blame placed on the tune and CAI. My dealer doesn’t give me any guff, but most are quick to assign blame to anything aftermarket.

Could there be a hidden code that can only be detected by certain scanners?
It is read differently and I’m not sure how that works. I took mine to Ford and they told me there were no trouble codes of any kind. I was having the issue when my car was new, before any modifications were done. The Mustang guy (tech) is the one who told me to disable advancetrac. I did that & never had another problem. I think advancetrac is a function of the BCM/ABS (as opposed to the PCM) so l think it only shows with special scan modes/tools. I can’t swear to that however.

Mine is a ‘14 so it may function differently, so check your users manual. I have to hold down the Traction-control button for 4 seconds, while pressing the clutch & brake pedals at the same time. Putting mine into sport/track mode doesn’t disable it on my car, it only adjusts some of the parameters to be more forgiving.
 
  • Like
Reactions: Beechkid

·
Registered
2019 mustang gt premium
Joined
·
10 Posts
Discussion Starter · #5 ·
Yeah, it won’t throw a regular code in most cases. A bad wheel-speed sensor or wiring issue can do this too. You may need to take it to a dealership to diagnose, but expect some resistance and blame placed on the tune and CAI. My dealer doesn’t give me any guff, but most are quick to assign blame to anything aftermarket.

It is read differently and I’m not sure how that works. I took mine to Ford and they told me there were no trouble codes of any kind. I was having the issue when my car was new, before any modifications were done. The Mustang guy (tech) is the one who told me to disable advancetrac. I did that & never had another problem. I think advancetrac is a function of the BCM/ABS (as opposed to the PCM) so l think it only shows with special scan modes/tools. I can’t swear to that however.

Mine is a ‘14 so it may function differently, so check your users manual. I have to hold down the Traction-control button for 4 seconds, while pressing the clutch & brake pedals at the same time. Putting mine into sport/track mode doesn’t disable it on my car, it only adjusts some of the parameters to be more forgiving.
That’s worth giving it a try. I’ll try it out tomorrow morning. I know a guy who has a special scanner so I’m going to try out your idea on the way to his place. If all else fails, then I guess to Ford I go. Thanks!

i tried what you said with turning off both the advancetrac and traction control and it still threw a wrench light with no code. I guess I’m going to Ford 🥲 thanks for your input though.
 

·
Super Moderator
Joined
·
3,840 Posts
i tried what you said with turning off both the advancetrac and traction control and it still threw a wrench light with no code. I guess I’m going to Ford 🥲 thanks for your input though.
At least now you know for sure it’s a defect rather than a quirk. Please do post back when you get this resolved.
 
  • Like
Reactions: 5.0 Coyote

·
Registered
2019 mustang gt premium
Joined
·
10 Posts
Discussion Starter · #7 ·
Have anyone found a fix to this issue? I’m having the problem with my 19 mustang gt. Only 15k miles on it and OEM throttle body
 

·
Registered
Joined
·
10,885 Posts
have you scanned it for codes?
if yes, what are they?
 

·
Registered
Joined
·
10,885 Posts
No codes are pulling up. Scanned it using multiple scanners of all calibers
now I see you mentioned that earlier, guess I neglected to scroll up before replying . . . other than that, and turning off advancetrac which you already did too, I got nuthin
 

·
Registered
2019 mustang gt premium
Joined
·
10 Posts
Discussion Starter · #11 ·
At least now you know for sure it’s a defect rather than a quirk. Please do post back when you get this resolved.
So I didn’t take it to Ford 🤣. But I found the issue. I did what I should’ve done in the first place and swapped the stock air box back in (should’ve done it from the beginning I know but I didn’t have an air filter for it and my naive mind thought there would be no issue with a new CAI), reloaded an older tune before the JLT, and presto changeo, works like a charm. So it has something to do with either the tune or the actual CAI. Will log it and send it to Lund Racing and hopefully they can find a fix, if not, guess I’m staying stock until I go forced induction.
 

·
Super Moderator
Joined
·
3,840 Posts
Thanks for the update. This may serve to help others who run into a similar problem.
 
1 - 12 of 12 Posts
Top