FDRS marathon update begins

[rjinaz]

Resetting the BMS is a myth. Yes a reset will momentarily show 100% but as soon as the BMS reads the battery it will again show the true SOC, the BMS system is working properly and can't be tricked. Your battery is most likely toast.

Yep... what I figured.

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[Big Dog Daddy]

Yep... what I figured.

I've learned since 21 when I bought my truck. I'm on my forth battery since new. And finally have a good one. It's 2 years old and still maintains a 75 to 85 soc all of the time.

 

[rjinaz]

Sucks to as I only had 4 modules left.
Technically the GWM is done... the USB loaded, but the truck is going into power save mode with the ignition off, so it cannot complete the update, and the BCM cannot be updated by me. Security login required.

 

[fordtruckman2003]

the truck is going into power save mode with the ignition off

Definitely a usual sign your battery is on last legs. Mine just randomly failed last December and it wasn't even cold out. ?‍

 

[rjinaz]

Definitely a usual sign your battery is on last legs. Mine just randomly failed last December and it wasn't even cold out. ?‍

Definitely not the 12v battery.
Went back to AutoZone and pulled the battery from the truck to test.
It's perfect. Sitting at 98% SOC, yet my truck keeps going into power save mode and reporting low SOC.
Could it be my hybrid battery is having issues? 

 

[fordtruckman2003]

Oh you have a PB! Sorry, didn't see that.

It could be your battery in the rear cab?
I know you have two on those trucks.

 

[rjinaz]

Still scratching my head on this one.
Diagnostics say there's nothing wrong with the charging system.
Bench test of the battery outside the truck shows it's at 98% SOC and still fully capable of putting out 800+ CCA of juice on demand.
Stick it in the truck and I get this....

Think I'll just get a pre-computer truck and do a resto-mod. Modern suspension, simple EFI system. No fancy computers.

Even my charger shows the battery is pretty much charged up.
Current draw is practically nothing.

 

[SilverPigeon]

@rjinaz Rick, Can I ask a basic (and maybe silly) question: where are you putting the negative lead of the charger? Battery terminal - or frame ground? It sounds like the BMS sensor isn't picking up true voltage; for that it needs frame ground ?

 

[rjinaz]

@rjinaz Rick, Can I ask a basic (and maybe silly) question: where are you putting the negative lead of the charger? Battery terminal - or frame ground? It sounds like the BMS sensor isn't picking up true voltage; for that it needs frame ground ?

Frame ground.

I know you have to attach it basically away from the BMS monitor, not on the negative terminal directly or BMS won’t see it correctly.

 

[SilverPigeon]

I too have a crappy H6 battery, but before commencing my long FDRS session, I externally charged it and tested it at 100%SOC and health. I then did a BMS reset and, while the BMS saw a decent SOC, made sure to put a constant 13.8V voltage supply to battery + and frame ground. Due to varying current draws, the voltage would fluctuate between 13.2 and 13.6, but FDRS never complained about low SOC during the 14 or so hours. Maybe give that a go?

 

[rjinaz]

I too have a crappy H6 battery, but before commencing my long FDRS session, I externally charged it and tested it at 100%SOC and health. I then did a BMS reset and, while the BMS saw a decent SOC, made sure to put a constant 13.8V voltage supply to battery + and frame ground. Due to varying current draws, the voltage would fluctuate between 13.2 and 13.6, but FDRS never complained about low SOC during the 14 or so hours. Maybe give that a go?

Here's the problem...
The battery is fully charged. It won't accept any more charge.
The truck is brain damaged and thinks it's only at 19%.
So, I suspect the BMS sensor is garbage.

 

[SilverPigeon]

Here's the problem...
The battery is fully charged. It won't accept any more charge.
The truck is brain damaged and thinks it's only at 19%.
So, I suspect the BMS sensor is garbage.

And a BMS reset doesn't change the FDRS detected SOC%? Before blaming the sensor, maybe a 15 minute drive and hook up FDRS after?

 

[rjinaz]

And a BMS reset doesn't change the FDRS detected SOC%? Before blaming the sensor, maybe a 15 minute drive and hook up FDRS after?

Been there... done that.... bought the T-Shirt. ?
I've reset BMS more times that I care to count. Driven it 10-12 miles and it still doesn't show the correct SOC.
The sensor is $28.
Apparently, there is a service bulletin out on these for the Lightening. Same part #.
I wouldn't be surprised if they are not available over the counter.


Edit:
Yep. As I expected. No dealer will sell them from their inventory as they are reserved for the Lightening service bulletin.

 

[Big Dog Daddy]

A side note to updating with FDRS. There is an ongoing issue with non-dealer FDRS logins right now that will stop you from installing the BCM update on your list. This update actually is very important in your case as it updates the charging system algorithm on your PB truck to maintain higher SOC levels at all times. A dealer would be able to do this update for you and they would not know about the issue of FDRS updating the BCM with non-dealer logins.

 

[rjinaz]

Ok... GWM update completed.
Only thing left is the BCM (can't do) and the APIM.
All others are done.
I went ahead and ordered a new BMS sensor, but was able to finish the GWM update while having it hooked up to the battery charger in Power Supply mode. Guess the GWM doesn't care too much about the SOC for the battery.

Will attempt APIM update after I replace the BMS sensor.

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