Hill descent fault repair

[BenBB]

I looked in my owners manual and cannot find anything about any of the P/W specific features. I cant even find anything about the hill descent control. I went to a mountain near me that has a section of unpaved unmaintained road so I could test the 4WD function. The 4WD low range is intense Love it. on the way back down the mountain, I decided to return to 2WD and test the hill descent control. Well; when I was in 2WD; it did not work at all, even with the trans in 1st gear. Does this feature only work when you are in 4WD low range?

Thanks for any info you may have

No it Hill Descent Control should work in any mode. I tried it out on a mountain dirt road in 2wd and "Drive", worked great (feels like it does engage 4wd as it sees fit though).

So I'm not sure if you guys have ever experienced issues like this, but I've seen threads of how people would have issues with the "Hill Descent Control Fault" popping up on their dashes randomly and how others would tell them to just clean their high mount brake light. Well I haven't really seen any step by step instructions on how to fix the issue. So as my good deed for the week, I've decided to post a step by step instructions list of how I repaired mine.

Stupid FNG question but...what the hell does that cargo light have to do with Hill Descent??? Just curious if there's a sensor in there or what. My Hill Descent appears to work and no error messages or codes, but one of those two incandescent bulbs is burnt out on mine so I'll seal that bad boy up as you did when I swap the bulb

 

[gwpfan]

Hill descent works in 2WD in mine, but if you going over I think 30mph..whatever speed it is, it doesn't work.

I'd bet the reason it doesn't work has something do with the brake light not giving the proper feedback.

Had a short once in my 95' F150 on the brake lights and once you put it in park, not getting out of park. Could replace the fuse, put it in drive and it would blow and go again, just couldn't put it back in park. Dumb design....granted they don't want you driving without brake lights, but if I was out and didn't know what I know I would've had to get it towed. Ended up being a short in my canopy brake light, luckily I had enough fuses on hand to get home to be able to troubleshoot.

 

[ROBO93]

Just had this happen this morning 30 min into a 5-hr roundtrip drive with a trailer on a 2010 Gen 1 6.2l with 178k miles. Your writeup takes the pain out of what I was sure was going to be a 3-4 week wait and $1k in transmission/computer repairs. Thanks for passing this along!

 

[ROBO93]

Update--pulled 3rd brake light and no moisture. It wasn't raining when it came on to begin with either. Blew the assembly out with compressed air and reattached. Pulled the negative battery lead for 5 min or so to hopefully reset the computer. Reconnected the battery and fired it up and it is now worse than it was to begin with. Hill Descent Control Fault still shows on the dash and now it doesn't complete the full engine warmup before dropping down to a rough running 750 RPM or thereabouts. That used to take about 30 seconds. Now it fires up and then drops to 750 with about 5 seconds and sounds like shit.

Like I said, it wasn't raining when this happened. In fact, it hasn't rained in almost 2 months. I've never had the issue before in the 6 years that I've had this truck. It would not be such a big deal but definitely does not drive normally since that light came on. It is almost as if the transmission is not downshifting like it normally would at highway speeds.

Any ideas?

 

[ROBO93]

UPDATE--apparently there is a wiring harness that got fried somehow and it is going to cost just over $1,000 and 6 days to fix. Sometimes I really don't like my Raptor.

 

[BenBB]

UPDATE--apparently there is a wiring harness that got fried somehow and it is going to cost just over $1,000 and 6 days to fix. Sometimes I really don't like my Raptor.

Well that sucks but hopefully solves the problem. Which harness? The one that runs down the back of the engine to the transmission (have heard reports of that one getting burnt against exhaust) or the one hanging down along the framerail behind the left front wheel (have heard of that one getting smashed against the frame or ripped loose) or is it for the third brake light?

 

[rschap1]

That does sound much different and worse then drying out the 3rd brake light. Good luck with the fix