BMS Fault - Alternator?

[jman1200]

I started getting a sporadic BMS fault (the battery image on the cluster's display).
Using Torque, I started monitoring what was going on and found that there were instances were the voltage would peak up to 16.4V but most of the time it would stay below 14V. Voltage with the engine off shows at 12.4V.
When it peaks above 16V, the AC system shuts down, I guess to protect itself.





Forscan shows the following codes:






Battery was about 2 years old and still under warranty so I went and got a new one. The issue persisted.
I disconnected the alternator and checked the connections. Did the same for the battery cables and main ground. No change.
It is my understanding that the voltage regulator for this vehicle is built into the alternator so before I go and replace it, is there anything else I should look at?

 

[kryptto]

so here is from alldata:

what is the state of charge or SOC? Note:Verify the battery state of charge (SOC) is greater than 70% before diagnosing any auto stop start concerns. Refer to the Workshop Manual Section 414-00, Charging System, for additional information.

In short for me - a ****** of a repair - faulty BCM - or maybe a door / seat module being faulty? read those attached docs - generator is still in the picture unfortunately.

Possible Sources

- Wiring, terminals or connectors

- Battery

- Generator

- PCM

- RFA (Remote Function Actuator) module
PINPOINT TEST G : DTC U3003:16
G1 RECHECK THE BCM (Body Control Module) DTCs

- Ignition ON.

- Enter the following diagnostic mode on the scan tool:BCM (Body Control Module) Self-Test.

- Using a scan tool, clear the DTCs. Repeat the BCM (Body Control Module) self-test.

Is DTC U3003:16 still present?

 

[Majestic]

Did you reset the BMS when you replaced the battery?

 

[jman1200]

Did you reset the BMS when you replaced the battery?

I did. 5x headlight flash + 3x brake.

 

[Majestic]

I did. 5x headlight flash + 3x brake.

I would do it with Forscan. I have never heard of someone successfully resetting it with any combo of switches, brakes, etc.

 

[Texas Marauder]

I did. 5x headlight flash + 3x brake.

I seen several procedures like this but, no proof that they work. A scan tool is needed to positively reset the BMS.

That being said, I don't think that has anything to do with your problem. Likely a bad alternator but, more testing is needed.

The relevant codes are P065B and P0625. The others are incidental to these codes.

 

[kryptto]

I seen several procedures like this but, no proof that they work. A scan tool is needed to positively reset the BMS.

That being said, I don't think that has anything to do with your problem. Likely a bad alternator but, more testing is needed.

The relevant codes are P065B and P0625. The others are incidental to these codes.

I have seen Texas Marauder be spot on - tbh - its never more than the most obvious. The other option pay the diagnosis fee and get an estimate - fix it yourself - I have done that a local shop charges $110 for a diagnosis. Yes you hope they are right - but that's the whole do you trust them. I have a trusted shop.

 

[Texas Marauder]

Additionally, you have a 2010 model. The BMS didn't start until the 2013 MY.

Three possibilities 1) alternator 2) wiring 3) PCM

 

[jman1200]

I would do it with Forscan. I have never heard of someone successfully resetting it with any combo of switches, brakes, etc.

I also reset everything that could be reset with Forscan.
The above procedure does work, you see the CEL go off for a couple of seconds and then come on. It only works once every time the battery is disconnected.

https://www.fordservicecontent.com/Ford_Content/vdirsnet/OwnerManual/Home/Content?variantid=8914&languageCode=en&countryCode=USA&Uid=G2246222&ProcUid=G2243071&userMarket=usa&div=f&vFilteringEnabled=False&buildtype=web

 

[Texas Marauder]

LOL, sometimes I think I'm talking to the wall. Your "procedure" affected the CEL. You really have no idea what it did, if anything. Assuming you have a 2010 as noted in your signature, it didn't reset the BMS because your car does not have a BMS. How can you tell? Is there a sensor on the negative cable? No there isn't. But, believe whatever you want.

2010:


2014:

 

[jman1200]

@Texas Marauder , no need to be rude buddy.
I'm just going by what I know, which could be wrong and if I am, educate me. No need to add comments like "LOL, sometimes I think I'm talking to the wall." or "believe whatever you want".
You seem to know about electronics and what you are saying makes sense but there is no need trash other people with your knowledge. At some point in life you'll learn to be humble.
Please don't help any further.

 

[Ta2dResqr]

@Texas Marauder , no need to be rude buddy.
I'm just going by what I know, which could be wrong and ff I am, educate me. No need to add comments like "LOL, sometimes I think I'm talking to the wall." or "believe whatever you want".
You seem to know about electronics and what you are saying makes sense but there is no need trash other people with your knowledge. At some point in life you'll learn to be humble.
Please don't help any further.

First, you are wrong and he did try to educate you. First, he told you that the procedure you listed is one of many that is claimed but does not always work. Further evidence to this not working is the fact that the link you posted comes from a Ford Bronco owner's manual. Second, he stated that the 2010 does not have a BMS system. Third, he told you the codes to ignore and the ones to concentrate on. Fourth, he gave you the principles of operation and all the needed wiring diagrams and told you it was most likely the alternator but, to diagnose it further.

Second, he is quite humble and often goes way out of his way to provide diagrams, links, and knowledge. He has taken the time to respond to this topic 3 times continuously telling you that you are going down the wrong path and that you need to look at the alternator.

Third, telling people that are taking their time to help you with a problem even after you ignore their advice is a good way to get a lot of the people with knowledge on here to ignore your posts and requests for help because, you are going to waste their time, not listen, and tell them to go away.

I suggest you go pop your hood and look at the negative cable and the generator charging cable and notice that there is no sensors. Then, I suggest you be a little humble and take the advice given to you by multiple people and use the diagrams and troubleshooting provided that apply directly to your vehicle and stop chasing some procedure you found online for a completely different model vehicle (that is a completely different platform and does not even share a drivetrain). Then, come back, apologize, and report what you found after trying the diagnostic paths that were provided.

 

[jman1200]

@Ta2dResqr, since you took the time to write that message, I'll give you my point of view.

On post #9 I was replying to Majestic not to Texas Marauder.
What was said in post # 10 was spot on but the added comments totally changed how the message is perceived:

Read this:

LOL, sometimes I think I'm talking to the wall. Your "procedure" affected the CEL. You really have no idea what it did, if anything. Assuming you have a 2010 as noted in your signature, it didn't reset the BMS because your car does not have a BMS. How can you tell? Is there a sensor on the negative cable? No there isn't. But, believe whatever you want.

Now read this:

Your "procedure" affected the CEL. You really have no idea what it did, if anything. Assuming you have a 2010 as noted in your signature, it didn't reset the BMS because your car does not have a BMS. How can you tell? Is there a sensor on the negative cable? No there isn't.

Different, right?

I spend more time than I should on forums and am an Admin of one. I love helping people and have written and documented multiple repairs I've done to guide others. Electronics is not my forte.
Written communication lacks tone, facial expression and gesture and many times the same message can be perceived differently when its written. This is why, as a general rule, comments like the ones quoted should be omitted.

Now, let's look at the chain of events:

1) 10:25 am - I post about my issue.
2) 11:04 am - kryptto provides lots of info. I don't have time to read the attachments, saved for later.
3) 11:30 am - majestic asks if I reset the BSM
4) 11:41 am - I reply that I did (as I thought I did) and explain how.
5) 11:50 am - majestic replies suggesting to use forscan.
6) 12:46 pm - texas marauder replies with an initial point of view reinforcing my initial thought of the issue being a bad alternator.
7) 1:03 pm - kryptto replies reinforcing the previous post.
8) 1:27 pm - texas marauder points out that the 2010 doesn't have a BSM and provides a document on how the system operates. Again, no time to read immediately, saved for later.
9) 2:01 pm - I reply to majestic's previous message and explain why (I thought) the procedure worked, not trying to ignore what was said about the BSM.
10) 6:06 pm I receive a message accusing me of being stubborn and not listening to the advice provided.

I'll leave it at that.

I'm not asking anyone to pick sides, this is not about that. I'm just stating my point of view.
I thank kryppto, majestic and texas marauder for the help and information provided up to this point.
______________________

Since then I've been looking a the attachments. Some of it I already did but will continue checking connections.

From the Principles of Operation:
The PCM is able to adjust the charging voltage according to the battery temperature by using a signal from the Intake Air Temperature (IAT) sensor. The PCM also uses other inputs to control charging system voltage such as the Vehicle Speed Sensor (VSS) and Engine Coolant Temperature (ECT). The voltage set point is calculated by the PCM and communicated to the voltage regulator by the GENCOM circuit based on the needs of the vehicle and the conditions.

My vehicle was low on engine coolant which I now topped up with no change. Maybe that affected the ECT reading misleading the PCM?

There is also something else I don't fully understand about the Check Charging System (let's not call it BSM anymore) going off after the engine goes above 2000 rpm.
A few days ago I disconnected the battery for more than 2 hours while I was cleaning some connections and the shift tables and other things reset. Something that changed is that before that I would get the CCS (Check Charging System) alarm after a short period of driving and it would go away, and then come back, and then go away... After that day, it comes on within 10 seconds of me turning the engine on, even if its still idling, and it won't go away.

I'll go over the connections again this weekend and will re-read the info sent. Some of it I don't really understand but will try my best. Will also go through forscan again to see if I can find a way to properly reset this system.

 

[J persons]

I've seen other Ford products that had wildly fluctuating output and it was usually a bad voltage regulator. Some autoparts stores can sell you just the voltage regulator but if not, you may have to buy a new alternator.

 

[ShatteredMJ]

It’s the alternator. You have a universal voltage spike affecting many modules. A single module failure or wiring issue would not do that. If your alternator is shorting your main battery fuse would have blown. It looks like a bad regulator/rectifying diod and is fixed by replacing the alternator. Just my 2 cents, I’m no expert.

 

[jman1200]

That was my initial train of thought (and still my main suspect) but then I read that the PCM in this car can command the regulator to raise the voltage. This is also noted in the Principles of Operation document shared in post #8.
Last night I ran some tests using Forscan, all came good, right now only code P0625 is coming up.



Not sure how to reset the Charging System Alarm, maybe by resetting the PCM - All Adaptations?

 

[jman1200]

Yesterday I finally replaced the alternator. Got a new 200 amp Motorcraft from Rockauto.
The alert is gone, problem fixed.

What a pain to replace it, not that hard but very difficult to work on due to space restrictions. Mechanic quoted 2.5 hours, took me 4 so not too bad.

This video was very useful. I did not remove the pipe shown at 1:10 or the coil harness. The fan assembly required a lot of pushing/pulling to get out so as the alternator once the bolts were removed. Taking the alternator out was also very tricky and had to spin it around to make it fit through the engine block and AC lines in that area.