Limp mode issues while off road

[shimmy]

I wheel my 24 Bronco Raptor and on several occasions now have run into the issue where the vehicle will enter limp mode. It seems to happen while going downhill, usually in rock crawl drive mode. All times have been high in the Rockies (8000+ ft elev). It is reproducible if I am stopped for a couple of minutes while facing a steep downhill in 4 lo (idle, in park, or just foot on brake).

Symptoms are the truck will bog down, lose all power, unable to rev above ~3k RPM. Christmas tree dash lights. Seems like full limp mode, it will barely move. Fully restarting the truck solves the problem (power down, open/close doors, lock, unlock, open doors, power on). No codes readable after the event. No dash lights after restart. No events with the ford pass app, always out of cell range.

Only mods are the Ford tune installed at the dealer.

Fully aware there are no vehicles that can be expected to be completely reliable while off-roading but this seems like a known issue. In some cases, could be quite dangerous—if I needed throttle to get out of a situation, in snow or mud or even just to avoid a hazard, it wouldn’t be there.

I have seen a few threads that never got resolved and am posting to see if anyone has gotten any useful responses from their dealer or otherwise. Any further information greatly appreciated!

 

[JohnGalt]

I’ve got no answers, but thanks for posting! All the electronics are cool in their own way, but unnerving.

I’ve had this happen about six months ago. Steep 30+ degrees descent right after climbing the same at about 6000’. I limped down the mountain to where I could get help (in case it wouldn’t restart) before attempting a restart. Restarted, worked fine and haven’t had an issue since. I didn’t pull codes at the time, but don’t recall anything when I did it some time later.

I’ve also seen two other Broncos lose their lockers when getting hung up in rocks with simultaneous lack of traction and high wheel speed. Especially concerning as we were on seriously difficult trails. This required a battery disconnect and then everything was fine. So if restart doesn’t fix an electronics issue, try disconnecting and waiting 5 or so minutes.

Finally, yet another Bronco lost lockers plus… ( I wasn’t there) on Dusy-Ershim trail when the wiring connection to the wheel speed sensor while in some rocks. Fortunately another guy had Forscan and a laptop to troubleshoot. They were able to repair the wiring and drive out without issue. Dusy-Ershim is not a great place to have a breakdown.

Probably time I get Forscan and learn to use it. It’d be cool if you could just run diagnostics off the dash touch screen. That’d be useful!