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Electrical: Intermittently, the car will not start after turning off, also headunit resets

10K views 25 replies 9 participants last post by  teslacadden 
#1 ·
Hey all!
I have a peculiar problem that I wasn't sure anyone might be able to weigh in on. These issues started a while back. I think they may be related.

Issue 1: Occasionally, when starting a car, all dashboard functionality gets reset, as if the computer had been factory wiped. Notably, this does not lose Bluetooth settings, which I presume are stored elsewhere. It does however reset instrument cluster brightness, dash screen brightness and all settings, current radio station. This happens right around once every month, or once every couple of months. This issue started happening a while back before the second issue.

Issue 2: Sometimes, when I shut off the car, it behaves as if someone had cut the breaker. Think of how it normally shuts down: you press the Start/Stop button, the lights stay on, music stays on, things keep running, just the engine is off. What I see happen however is a similar sensory effect to you watching TV at home and the power going out for the neighborhood. I push the Start/Stop button upon parking, and everything goes away. Speakers, dash lights, head unit, dome lights, headlights, foot well lighting - I mean literally everything. It's about the same effect as the car not having a battery at all. Pressing Start/Stop again at that point will not start the car again: it's dead for all intents. I presume something gets tripped up though, and something does get rebooted eventually. After about 5-10 minutes of waiting, the Start/Stop can be pushed again and the car will came back as if everything is normal - though with the dash completely reset as in the Issue 1.

I've been dealing with this for maybe a year or so due to its intermittent nature. Recently though I dropped my car off at the dealer for an oil change and to fix my weather stripping and swollen lug nuts - the latter of the two issues is something I have literally never experienced on any vehicle before, and as I pulled into their receiving bay, the did that #2 thing. The tech got into the car to try to start it to look at the mileage, and nothing. Some other techs happened to be walking by, and multiple people saw this happen. A person who I assume was one of the managers even remarked with concern that they had to get to the bottom of it. He also further inquired - politely - if my car would come back eventually, as I presume he was thinking I was now blocking their receiving bay completely.

Well, they've had the car for almost a month at this point, and have had no luck reproducing the issue. I personally don't think it's an issue you can just repro. I've had to deal with issues similar to that before, where there's no repro for the problem, and the only way to go forward is to start pulling things apart. In my case it's with Software systems, but it sucks regardless.

I think they are going to have to hand the car back to me as I believe they are out of ideas. I turn to you now, folks, in case someone has any suggestions for troubleshooting, fixing, or otherwise.

Thanks!
 
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#3 ·
Woof, I honestly don't know, but that's an interesting thought. Not familiar with electrics in cars tbh. Followed the ground wire lead, and here's at least one place I end up:

Very interesting. Looks like it's at least a point of discussion for our ST brethren
 
#5 · (Edited)
Original battery?

Edit:

I ask this because I took my car to the dealer because it had a few "electrical quirks" that were starting to pop up. The infotainment system would factory reset for no reason once a week. also I told them that the auto start stop feature just stopped working. Me being who I am was thinking to myself that this had to be because of the low voltage of my then 2 year old battery. The dealer also kept my car for a little over a week, and decided to do nothing because they said "there is a aftermarket alarm on the car soooooo....." I picked up my car and never took it back except for the recall work and the free oil changes that come with a 7 year extended warranty. I changed my battery my damn self. most of the "quirks" went away. The damage to the APIM was too far gone to save. Thankfully they replaced it. If it goes bad out of warranty again, I'm just gonna throw a Pioneer in there like I put in my truck. The sound quality of my truck puts the RS stereo to shame already.
 
#7 ·
Original battery, yeah. Considering when this started happening, only 3 years out of a battery? I also can't see how an older battery would explain electric quirks - like the resetting maybe? but the fact the car just shuts off? Especially after being driven for a while. It never has even an iota problem starting when it's just been sitting around. Every time I've had battery issues it was due to the older battery not providing sufficient cranking voltage - it dipping too low on startup. Every time these cars also exhibited real **** startup for a while before finally being unable to do so. In my case when the car starts, it starts right away, no problem (though having reset the head sometimes). The shut-off issue I am experiencing specifically pops up when I do drive somewhere, stop, park the car, shut off the engine - boom, dead, no start, until something reboots and starts to function again, and then again no issues at all for a while.

As an aside, the APIM did have to be replaced already. I want to say this was about a year ago. The issue exhibited there was that I somehow could not update to a new version of Sync 3 (3.0 from 2.2 I think), even after extensive troubleshooting and hacking of files based on a different thread here. Brought it into the dealer, and they ended up replacing the APIM.
 
#8 ·
Yup, change that battery.
My car would do the same things, hasn't done that since I've replaced the battery. I haven't had an oem Ford battery last more than a year in the past 4 fords I've bought. The other cars just stranded me with no warning, no symptoms, full power on cranking, park the car come back to it 30 minutes later and completly dead. Couldn't even get them jumped off.
My wife's fusion when it died, I had parked it at a ball game, came out after and it cranked right up, but the car actually died sitting in traffic trying to get out of the parking lot. Battery was shot.
Weak batteries cause all kinds of electrical glitches in modern cars.
 
#10 ·
I remember batteries lasting almost a decade. For some reason this car just eats them up.

Before I changed the RS's battery, it would start up just fine. Never had a slow crank. But the voltage would dip to the high 6 volt range while cranking. The resting voltage was around 9 to 10 volts after sitting parked for about 10 minutes.

I bet you that your dealer will not replace the battery for free. If they do, go buy a lottery ticket right away.
 
#11 ·
D1rt, that's interesting! I have not had the car shut off while driving, and I've not been stranded by it ... yet. It weirds me out that it comes back after a while. Thought now I am wondering: if there is some kind of issue with power regulation from the battery, it's conceivable the voltage dips too low for some reason upon shutting the car off causing everything to trip.

And yeah, EvanRyan, I feel like batteries used to last for me 5-7+ years. My Civic's OEM battery at the time of sale was still going strong on year 8 with zero issues! My SO's car needed a battery recently at I wanna say 9 years? Also OEM.

So what do folks recommend for batteries? The dealer still has my car, so I might try to get them to cover a new battery, but I bet they will be unwilling to. They were unwilling to cover the freaking weather strip, something that I have never had fall off on any vehicle I've ever owned or worked on. Yet, it did fall off on one of my doors. If you ask me, a manufacturing issue, but oh well.
 
#16 ·
You don’t need the oem size battery. It takes very little cca to start the EcoBoost. I have an 170 cca rated battery with the grimmspeed mount and it starts just fine. I don’t however use the auto stop/start, but I do have a 300w amp running in place of factory sub amp.
 
#12 ·
Did your auto stop start work by any chance? That quitting seems to be the first sign of a low battery.
But yeah my rs would do the whole black out and lose all settings thing. Stop to pump gas, get back in the car and everything was black, couldn't start the car for a few minutes then out of nowhere everything was back. Oddly enough it would usually have juice to unlock the door then go black, only locked me out once.

The fusion tripped me out, it was odd, enough power to crank the car just fine, but died a minute later while it was running with the alternator. But it was the battery.
 
#13 ·
Did your auto stop start work by any chance? That quitting seems to be the first sign of a low battery.
But yeah my rs would do the whole black out and lose all settings thing. Stop to pump gas, get back in the car and everything was black, couldn't start the car for a few minutes then out of nowhere everything was back. Oddly enough it would usually have juice to unlock the door then go black, only locked me out once.

The fusion tripped me out, it was odd, enough power to crank the car just fine, but died a minute later while it was running with the alternator. But it was the battery.
I haven't tested the Auto Stop/Start, as I typically just hit that button as soon as I get in and turn it off. It's a good lead, I'll test it out on the drive home. Dealership has my car ready, so I'mma go pick it up and start doing my own troubleshooting since they couldn't figure it out.
 
#17 ·
Had an issue where the HVAC would shut off and the AWD / Hill Start would give error messages stating they are no longer be available. After much trial and error I found there are wires that run DIRECTLY under the dead pedal (are you kidding?). After 20k they frayed and when I put my foot on the pedal the issues would crop up. Rerouted them and all's well since.
 
#19 · (Edited)
I just replaced my battery today and so far the only two inconveniences I've noticed are that I had to recalibrate all windows before express close (or whatever the feature is called that allows to fully close a window by pulling on the switch until it clicks) started working again. And I had reprogrammed my doors to not lock automatically which got reset.
ForScan fixed the windows and the same process for the locks will fix the locks.
 
#20 ·
Hm, is this doable without ForScan - the window thing? I just got my new battery today, going to put it in tomorrow
 
#22 · (Edited)
I don't have a Windows laptop to use with it unfortunately. The manual process with roll-down, hold 2-3s, roll-up, hold 2-3s does work. Just tested.

Now I'm trying to figure out how to reset the battery monitor. I've seen some suggestions to do the following:
1. Power ON
2. Fogs 5 times (or 8 or 3, seems folks can't agree on this)
3. Hazards same number of times
Funny enough this actually just sends the car into training TPMS mode. Not desired.

Looks like there's a different method suggested here: Throwing Codes after Battery Change. Going to try it later.

As an aside, I wish there was a full list of magic RS combos somewhere! Freaking Konami Code over here.

Edit: Nope, no dice. Either instructions are unclear, or that combo does not work. I tried a few different combinations of hazards, headlights, on/off, brakes
 
#25 ·
Changing the battery! Followed by resetting the battery minder after, of course. The dealer never figured it out either. I have mentioned it to one of the tech advisors since - that hey, maybe if there are gremlins, it might actually just be battery - but they just kinda shrugged with a disingenuous "oh wow," and I am pretty sure ignored whatever I had to say. Assholes.

My first change of battery actually still kept dying on me, and I was figuring that maybe truly I had befallen under the wrath of electrical gremlins. After some back and forth on it with a multimeter, I figured it may have had a dead cell: showing ~10V on cold, instead of the expected 12V, as if one of the six cells was not there. Got Advance to use two different machines - first one said all's well, I let the battery discharge the surface charge then, and asked them to retest it. The manager got a different tool, and this one actually said the battery needed a replacement. The second battery replacement has been working great since. Auto Start/Stop came right back after the second replacement as well, which was a good sign.

I can't promise it will work for you, but the battery was what did it for me.
 
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