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'Check Charging System' message...

A couple times at autocrosses, I've had a 'Check Charging System' message pop up in the cluster when restarting for my next run. Last year, it happened once, but I was never able to replicate it. (I also stopped shutting the car off between runs pretty shortly afterward, and no more issues.)

Today, it happened again. Then after shutting off and restarting to try to clear it, I got a MIL for a P260F (Evap system) fault code. The P260F did not happen last time.

I was able to clear the fault, and neither the fault nor the check charging system message returned, but I'd like to resolve it rather than hoping it does not come back. Has anyone else seen issues like this?

Of note, the car is a 2011 Mustang GT, and this has only happened at autocross events, and only when restarting the car (after shutting it off after a prior run). I also had an OBDLink MX connected both times when it happened (to log OBD data with the Track Addict app).
 
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No observed issues other than the message above. The battery was fresh when I bought the car last Spring, and seems solid.
 
I found another discussion here with similar symptoms where the issue was the PCM relay. Tried that as a quick and easy step, but no luck...

If I shut off the car between runs at an autocross, I still get the 'check charging system' message when I restart. This time, the P260F repeated as well.

It seems like this has to be heat-related. It only happens at autocross events, and only if I shut down the car between runs (without an extended idle prior to shutdown). If I let the engine idle between runs, no issue.

The battery is pretty recent, but I assume the alternator is original (2011 / 28k miles). Ideas/thoughts on likely root cause?
 
This is a shot in the dark. I know on the 05 to 09 mustangs the alternator was poor at high RPM and would break. It wasn't until 2009 they released the denso brand alternators that could handle the RPM. I am pretty hard on my car even in normal street driving especially merging onto highways. My car started having the charge check charging system error also and after much testing I found it was my alternator giving up after so many high RPM instances. After I swapped to a denso version of the alternator it solved my problem. However through the process I learned a lot about the charging system in general. If your battery doesn't hold 12 volts of charge or higher while the car is off, your battery is already weak. If you use the same battery on and alternator or even a new alternator it could eventually ruin the alternator. the warranty for my new alternator stated this specifically. However it will not cause the check charging system error. Also with the vehicle running you should be getting a voltage that is higher than 12 volts. I can't remember exactly right now, but it's above 12.4 volts. I would have to Google what you're looking for, but I'm sure it's readily available. If your alternator is not putting out that power, it is suspect. however on my mustang it would put out that power level, but would occasionally stop doing that and thus the warning.

TL;DR

The check charge system warning is very likely your alternator. If you replace the alternator also make sure your battery is behaving in spec, because if it is not it can kill an alternator prematurely.
 
I had this error pop up a couple years ago. No issues with power or anything just the error would pop up and mainly when running on track. Swapped the alternator and has been good since.
 
I had this issue on my 350 after two days of spirited driving in Rosamond, CA. Mine turned out to be the alternator. Dealer still has my car. They had a hard time replicating the issue but it only took me a spin around the block to trigger the fault. Charging seemed erratic when the fault was showing but it seemed to reset itself if the rpm was kept low.
 
It sounds like an alternator swap is likely in my future...

Is the Boss 302 alternator kit the sweet spot in terms of cost/performance for an S197?

How difficult is the R&I on the S197 Coyote cars?
 
76
51
Exp. Type
HPDE
Exp. Level
3-5 Years
Dothan, Alabama
Don't want to hijack the thread but I've also seen this issue quite often with my 14 GT, but I haven't seen any crazy drops in voltage while the car is running. It happened first time earlier last year but ended up being the battery, but it came back after my last outing before COVID. Do you guys think the stock voltage gauge is not accurate, and I may still have an alternator issue?
 
6
10
Exp. Type
Autocross
Exp. Level
Under 3 Years
Post Falls, ID
I've been getting that same error message over the past few track days. Just installed ATX-20 HD and fired her up this morning and voltage read 16 and the got the same message again. Anyone seen that high of voltage?
 
168
36
I had the same same check charging system light on my 12 Boss 302.
First time was coming off the track at Watkins Glen.
Scanned it and alternator showed bad.Replaced it and good for awhile and charging system light came back on and off.
Ended up changing the battery harness.That ended the problem.
FYI the trans has to be removed to R&R the battery harness.
I believe the one of the three tiny wires to the alternator plug gave up.
 

Bill Pemberton

0ld Ford Automotive Racing Terror
6,837
5,901
Exp. Type
Time Attack
Exp. Level
20+ Years
Blair, Nebraska
Th alternator could be the main culprit as many noted, and frankly if you talk to many racers who track a lot replacing an alternator is quite common. When I lost mine during the Mustang Roundup last year I actually had one competitor offer me his spare alternator that he said he always carried since they seemed to be a weak point. Good luck and hopefully that is your fix, since it would not be that unusual on any 11 year old car actively driven.
 
179
205
Exp. Type
HPDE
Exp. Level
3-5 Years
Raleigh, NC
I've been getting that same error message over the past few track days. Just installed ATX-20 HD and fired her up this morning and voltage read 16 and the got the same message again. Anyone seen that high of voltage?
Yep. I had the H5 battery. Was fine for about the first 12 months, then the voltage would fluctuate frequently. Eventually it would hit 16V and I was getting warnings that the system would shut down. I am of the opinion that the Ford Smart Charging System is not compatible with anything but lead-calcium batteries.
 
6
10
Exp. Type
Autocross
Exp. Level
Under 3 Years
Post Falls, ID
I had the same same check charging system light on my 12 Boss 302.
First time was coming off the track at Watkins Glen.
Scanned it and alternator showed bad.Replaced it and good for awhile and charging system light came back on and off.
Ended up changing the battery harness.That ended the problem.
FYI the trans has to be removed to R&R the battery harness.
I believe the one of the three tiny wires to the alternator plug gave up.
yikes - thanks
 
6
10
Exp. Type
Autocross
Exp. Level
Under 3 Years
Post Falls, ID
Th alternator could be the main culprit as many noted, and frankly if you talk to many racers who track a lot replacing an alternator is quite common. When I lost mine during the Mustang Roundup last year I actually had one competitor offer me his spare alternator that he said he always carried since they seemed to be a weak point. Good luck and hopefully that is your fix, since it would not be that unusual on any 11 year old car actively driven.
Thanks Bill. So I ran yesterday afternoon and this morning. Yesterday afternoon it leveled back off at about 14.6. This morning I get in and fire up, lights are going off, charging system service indicator comes on, the other screen is telling me to start the vehicle or shut it off and that timer bar shows up. Then I lose power steering. Restart same. Restart and I'm waiting to get into the starting spot from our hot pits and I get steering back. All this while I'm reading 15.5 up to 16.1. I drove a few laps and it didn't come back down so I got back to my rig, borrowed a friend's battery, same issue. So several of us are thinking it must be the alternator. Have it coming Tuesday; so I'm done driving for the weekend. Could be worse but a bummer nonetheless.
 

JDee

Ancient Racer
1,516
1,540
Exp. Type
W2W Racing
Exp. Level
20+ Years
halfway between Mosport and Shannonville
I'm no expert on auto charging systems, but to me that sounds more likely that the regulator is not working. I come from a marine DC charging background and if you got excessive voltage (14.2 or slightly above that was the max you'd see under normal charging conditions) it was for sure a regulator problem. Maybe the regulator is built into the alternator on cars? Cruising boats used programmable 4 stage external regulators. 15 - 16 volts should kill a battery fairly quickly I would think?
 
6
10
Exp. Type
Autocross
Exp. Level
Under 3 Years
Post Falls, ID
I'm no expert on auto charging systems, but to me that sounds more likely that the regulator is not working. I come from a marine DC charging background and if you got excessive voltage (14.2 or slightly above that was the max you'd see under normal charging conditions) it was for sure a regulator problem. Maybe the regulator is built into the alternator on cars? Cruising boats used programmable 4 stage external regulators. 15 - 16 volts should kill a battery fairly quickly I would think?
Yeah I think you’re spot on. The regulator is built into the alternator on these. Just reading some horror stories about the odd wire getting damaged or harness replacement …I’ll circle back here after I install the new alternator.
 

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