Defective Battery, Recall 24S24 and other topics

[SportBob001]

I was in and out in less than 45 minutes today for the update on the recall. Great service as always at Classic Ford in Smithfield.

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[Dude]

I am not an engineer so my wording might not be entirely correct. So the BCM and PCM are supposed to be able to check the battery charge level and are not doing that and therefore the BS still allows the auto start stop to shut the engine off and at some point the battery charge is low enough that it cannot restart the BS? Is it also that the systems are charging the battery properly until some point where it is no longer doing that?

I am an engineer and everything i say in this post is 100% conjecture because none of us know the charging system algorithms implemented by Ford in the BCM and in the PCM.

We don’t even know the division of charging system work implemented in the BCM and in the PCM.

We do know that the BCM is a set of software instructions and a set of configuration data (parameters). Ford does not completely redesign the BCM software for each different vehicle - the configuration data allow parts of the software to work across a wide range of vehicles .. that’s why you said earlier it worked fine in Ford Escapes and Edge. That’s partially due to the configuration data was correct for those vehicles.

The PCM is similar but of course its software and its configuration data is completely different from the BCM. For example, we have been told that one of the PCMs job is to set the alternator charging output (possibly under the control of the BCM telling the PCM but that’s conjecture on my part).

My next conjecture is the BCM is primarily responsible for monitoring the battery. That would include knowing how many times the battery goes through a “charge cycle”. We do not know Ford’s definition of a charge cycle so I would just be guessing to say more. The BCM probably is responsible for calculating the State of Health (SOH) of the battery but again we do not know the algorithm. The BCM has lots of other jobs - you can google for some typical info on that.

Here is a stylized diagram of some BCM implementation (block diagram). It is not specific to Ford - I’ve never seen details on the BCM block diagram for any Ford.

The BCM may be involved in controlling the Auto Start/Stop (in conjunction with other modules). Your post listed a lot of good info about Auto Start/Stop. Hopefully now you can see how it is possible for the BCM configuration data being incorrect about the condition of the battery will cause Auto Start/Stop to work incorrectly.

And because the PCM configuration data was incorrect, we can guess that the PCM was not running the alternator sufficiently to keep the battery properly charged. We do not know the algorithm for this nor do we know what it is Ford fixed in the configuration data for the BCM and PCM.

We all hope Ford got Recall 24S24 fixes right and the issues have been resolved.

Time will tell.

 

[Dude]

Good info.... One would think it would be easy to pop that info onto the instrument cluster and make it available for day to day driving...

It is easy and you can buy aftermarket devices to display information made available on the OBD port.

 

[Dude]

One thing I'm curious about is how the auto start/stop determines battery voltage/SOC when the engine is running and the alternator is operating.

The BCM monitors the state and health of the battery and communicates with the PCM we believe to set the alternator output.

I assume the BCM controls auto start/stop or controls whatever other module (if any) that implements auto start/stop

As posted earlier, these items influence the auto start/stop behavior and I believe the BCM has access to all of the items:

The system does not stop the engine if:
• The driver door is open.
• The driver seatbelt is unfastened.
• Your vehicle is at high altitude.
• The heated windshield is on.
• The transmission is in manual (M).
• Your vehicle is on a steep grade.
• The engine is warming up.
• The outside temperature is too low or too high.
• The battery charge is low.
• The battery temperature is outside the optimal operating range.
• The engine is required to run to maintain interior climate and reduce fogging.

 

[thomasm23]

I had the 24S24 recall done yesterday. Before applying the software update, the dealer called to inform me that the AGM battery was failing. This is a 2 year old Motorcraft AGM battery that replaced the original Motorcraft AGM.

I told the dealer to apply the software update and retest the battery after. This time the battery tested good.

 

[sajohnson]

I had the 24S24 recall done yesterday. Before applying the software update, the dealer called to inform me that the AGM battery was failing. This is a 2 year old Motorcraft AGM battery that replaced the original Motorcraft AGM.

I told the dealer to apply the software update and retest the battery after. This time the battery tested good.

I've had that experience before -- inconsistent results.

 

[Bucko]

All the more reason to eliminate the auto stop

Easily done...turn it off after starting.

 

[Switchblade]

I got this recall done today in about half an hour (perhaps even a little less) at my dealership.
Is that even possible to do it so fast...?
The dealer bulletin allows more time for this 24S24 recall.

 

[KidWiff]

It is easy and you can buy aftermarket devices to display information made available on the OBD port.

I understand aftermarket devices are readily available. I’m just saying that, with all the self diagnostic tools and electronics on board, we shouldn’t have to purchase aftermarket. The info is in the computer, simply make it available on the instrument cluster…

 

[Dude]

I understand aftermarket devices are readily available. I’m just saying that, with all the self diagnostic tools and electronics on board, we shouldn’t have to purchase aftermarket. The info is in the computer, simply make it available on the instrument cluster…

Totally agree. But it is what it is. Try the engineering test mode to see the voltage. The aftermarket devices display many other parameters like transmission temperature, coolant temperature …

 

[Major Kong]

mobile service tech arrived and cast the demons out of the software yesterday
begone bugaboos out out
all good now

 

[RushMan]

I got this recall done today in about half an hour (perhaps even a little less) at my dealership.
Is that even possible to do it so fast...?
The dealer bulletin allows more time for this 24S24 recall.

If they skipped hooking up a battery charger as specified in the procedure, and didn't reprogram the TPMS afterwards, sure.

 

[Bucko]

mobile service tech arrived and cast the demons out of the software yesterday
begone bugaboos out out
all good now

Did the service tech toss chicken bones in the air and chant "be gone charging demons, be gone"?

 

[Milehifireguy]

Had the 24S24 recall done 2 days ago. So far no adverse effects. I hadn’t been experiencing any of the related issues prior. Keeping an eye on things.

 

[coopny]

I had the recall work done. Mobile service, within 30 minutes. Completely painless except it overwrote my powerport timeout (I don't like the 1 hour 10min default timeout as my cellphone booster draws 1.8amps, I'm just turning off my power splitter on engine stop until I get around to getting FORscan to reprogram a five second timeout in.)

I'm cautiously optimistic that this may resolve issues that many of us have had with the EFBs and lifespan. It's not just about battery quality, it's about how the BCM/PCM manage charge to the battery. If they were consistently shortchanging charging the battery or otherwise mis-charging it (overcharging can be damaging too), it could explain the short life of a lot of batteries.

I like the idea of a "battery looks bad, have it checked" warning and quite honestly, I'm surprised it hasn't been implemented earlier. The computers in the car know the state of charge, they know the voltage sag/dip, delay, etc... these are the types of things that battery testers look at. The BCM/PCM have the benefit of doing this over a long period of time since they're always powered and monitoring all stop/start events.

Via reddit:
I work in the auto industry on the software side and this is the most accurate answer I've seen so far. Realistically if we wanted to do this without the car randomly loading the battery itself to test, we could design a feature that checks cranking amps during normal startup and compares it to an experimental value that is near the operating limit, but this isn't done because if the operator is requesting a startup they are probably in the vehicle, minus remote start. and if the turnover feels/sounds sluggish, then your battery is probably getting old and is ready to be replaced soon. It's easily implemented to check but very near the bottom of features that sell a car. When we're working on a new program, so often do we scrap a feature I think is awesome simply because market research says it's not worth the money.

Now we have a recall and to mitigate risk/litigation, Ford has prioritized a feature that the hardware has been capable of all along.

I've had some issues with my BS and some reservations - I'm not happy about all aspects of my vehicle (not getting in that here) - but as someone who has been skeptical on the battery/battery management system of the BS on this forum in numerous threads and posts, I'm actually very very happy to hear that Ford has put priority on a "your battery could be going bad, get it checked" warning, before the car won't start and you can't get to work, or when you're at a store in 95F weather and can't start your car. (Or god forbid with auto stop/start that it's while in the middle of the road).

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