Steering Wheel Lights Don't Work - Reset SJB? 2014 GT Manual

[DocG5]

Hey guys, first time poster, just got my Mustang about 4 months ago.

Here's the issue: Steering wheel button lights, headlamp switch, trunk pop/hazard/tc control button, and puddle lamps all do not light up at night with lights on. Dimmer switch does not effect these items.
Checked fuse F10, it was popped. Replaced it and none of these work still but the fuse is still good and is getting 12v. According to the wiring diagram (I'll put it below if I can) this circuit is controlled by a FET and a "Micro" (assume that means some sort of micro computer). I've been wondering if maybe the SJB has a code that needs to be cleared or reset? How would I do that? I have Forscan and a OBD cable but don't know where to find the right module to reset or what to do in Forscan really. I don't want to mess anything up further.

I saw that this is a really common issue on the Flex model. Here is one post with my exact issue: No Lights on Steering Wheel/Shifter for 2009 Flex
A lot of people say the dealers were able to fix it but I would like to fix it myself if I can.
Not much luck finding a solution for Mustangs. Any experience here or know what to try next?

 

[DocG5]

Some more info that may be relevant - The previous owner of this car had swapped in the BOSS 302 cluster and he ran with that for a while. He swapped back in the stock one before selling it to me. Was wondering if maybe unplugging that with the battery still hot could pop the fuse? Seems unlikely though as the IPC isn't part of this circuit. But maybe the wrong cluster threw some code at the SJB that needs to be cleared? Idk grasping at straws here...
I've also backprobed at C210 pin 19, as shown on the diagram, and I got 2.5v on both ends of the connector. Not sure if this is correct though because I have the manual coupe so I don't have the overhead console or the transmission selector so maybe this wire is used for something else now?
My electrical knowledge is limited, so please bear with me!

 

[DocG5]

Okay, another update: I backprobed between C2267 (the trunk/hazard switch, since it's the easiest one to access) and between pin 39 on C2280B on the SJB side and I got solid connection. 0.1 ohms of resistance. So there's no short or open circuit as far as I can tell. So my problem has to be with the SJB not sending power. Hopefully my FETs aren't fried. And I have no idea why the original fuse would have popped. I took the time to look around the harness in the center console, particularly where the splice is (S224) and everything looked fine. It's not near where any connector tabs are or anything that could have pinched it. I guess I'll now try to figure out if I can do something in Forscan. If anyone has any knowledge on what to do in Forscan I would greatly appreciate it!

 

[DocG5]

FIXED IT! Hopefully this is my last update. Posting for anyone who experiences a similar issue.

Initially, I had bought and tried one of the cheaper OBD USB cables that said it worked with FORscan, this one had the little HS->MS toggle switch on the outside. This cable wouldn't let me see all of the modules, particularly the GEM/SJB that controls these lights. So I had to bite the bullet and buy the $60 cable that is recommended from FORscan. Initially, when I plugged in the new cable, it didn't work either, it was still showing me the same modules that the cheaper cable was. To fix this, I had to unplug everything, recycle the ignition, and plug the cable back in. When FORscan prompts you with the "Hey we know this car, want to use this previously saved profile?"... CLICK NO! This will force FORscan to relearn your car and search for all available modules. This brought up about 2x as many modules as before, one of them being the GEM/SJB!
Looking at the DTCs, there were a ton of faults from the GEM/SJB saying that the steering wheel buttons, headlamp switch, puddle lights, and trunk pop switch were all cut off from receiving power. And there was one code saying a short to ground was detected, which is likely what triggered the protection mode. I decided to clear the DTCs to see what came back on, hoping that the module with the faulty wiring would show itself by not working. I was willing to sacrifice another fuse to find out. But luckily everything came back on and is working! I will keep an eye on it and update here if anything changes, but I've driven a few times now and everything still works! Bonus, I found out this car has the Pony projectors! Thought it just had the standard puddle lights.

Still not sure what caused the initial short and popped fuse. I am going to assume something was unplugged that shouldn't have been during the previous ownership. Hopefully, this is the end of this issue for me!

TL;DR—Buy the recommended FORscan cable. It's the only way to see all of your car's modules and clear hidden DTCs.

Hope this helps!

Video proof of it working for those that care

 

[Spence340]

Thanks for following up with the fix, hope it was a permanent one.

 

[DocG5]

Thanks for following up with the fix, hope it was a permanent one.

No problem! Bugs me real bad when someone with my exact issue doesn’t post their solution haha. If anyone has a question you can message me

 

[Ritcher]

Hi,
I'm having the same issue you had — the steering wheel button lights, headlamp switch, and the trunk pop/hazard/traction control buttons all stopped working right after I disconnected and reconnected the battery. I already replaced the F10 fuse, but the problem is still there. Do you know what else could be causing this? Any help would be really appreciated!

 

[DocG5]

Hi,
I'm having the same issue you had — the steering wheel button lights, headlamp switch, and the trunk pop/hazard/traction control buttons all stopped working right after I disconnected and reconnected the battery. I already replaced the F10 fuse, but the problem is still there. Do you know what else could be causing this? Any help would be really appreciated!

Hey! Sounds exactly like what I had. If your F10 fuse is still good after running the car and doesn’t pop again then your SJB (smart junction box) likely has a stored code on it that is preventing it from sending power to that circuit. You’ll need to buy the recommended forscan scanner and download the software on a laptop to clear the code. A regular OBD scanner won’t be able to see that code. Maybe a higher end scan tool could see it but I’m not sure. You could also probably take it to Ford and have them clear the code but they’ll likely charge you.
Once that code is cleared everything should work again.

 

[delroy]

Congrats on the troubleshooting Doc. Very impressive. Re the pony projection, I think that might be part of the premium package. I have that on my car too. Mine is a 2014 GT Premium coupe with 6MT and 30K miles which I just got in May. It's never been winter driven and is pristine! Too bad you are in Ca. It's a long way from Hamilton ON.

 

[Ritcher]

Hey! Sounds exactly like what I had. If your F10 fuse is still good after running the car and doesn’t pop again then your SJB (smart junction box) likely has a stored code on it that is preventing it from sending power to that circuit. You’ll need to buy the recommended forscan scanner and download the software on a laptop to clear the code. A regular OBD scanner won’t be able to see that code. Maybe a higher end scan tool could see it but I’m not sure. You could also probably take it to Ford and have them clear

Thanks a lot for the info! That makes sense now. My F10 fuse is holding fine, so it sounds like the SJB code might be the issue. I'll look into getting Forscan and a compatible scanner to clear it, since I'd rather try that before paying Ford to do it. Really appreciate your help!

If possible, could you also share a photo of the Forscan setup you're using? That would be a big help.
Thanks.

 

[Ritcher]

Hello Sir,
Waiting for your response

 

[DocG5]

This is the scanner I bought: scanner
And here’s where you can download Forscan: Forscan download page

I am not sure if it’s necessary, but I got the free 2 month trial to the extended license, all it takes is putting in an email address and following a few steps on their website. It might be necessary for this procedure so I’d go ahead and do that.

 

[Ritcher]

Thanks for your reply.
The website is not working, the page isn't open
Appreciate all u do

 

[slonison]

Thanks for your reply.
The website is not working, the page isn't open
Appreciate all u do

I believe this is the one he used

https://www.amazon.com/OBDLink-EX-FORScan-OBD-Adapter/dp/B081VQVD3F