"Maximum Battery Charge Level Reduced" message behavior

[Hitmakr7]

Tesla Family,
Something weird, but I'm sure someone here knows the answer. I have a 2012 Tesla Model S P85 with 180k miles. For the most part, I've been sinking a great deal of $ for service, but love the car. It still rides great and functions as it should. However, after the Tesla mobile service replaced my 12v battery replaced after it died on my unexpectantly without any warning, I now get the "maximum battery charge level" message but here is the thing. Its sporadic. Sometimes I can trigger this message by going up a sharp hill and a few minutes later, it goes away. When the message is active, I can't charge past 70 miles. When it goes away, I can charge it fully.

Is this normal? Could it be a short or bad connection? Or is it simply time to get rid of the car?

Thanks Everyone!

 

[Gixx1300R]

Imminent battery failure

 

[NV Ray]

Have you gotten any BMS_u029 or BMS_u018 alerts? Did you do a recent software update?

 

[CleanDemon]

Tesla Family,
Something weird, but I'm sure someone here knows the answer. I have a 2012 Tesla Model S P85 with 180k miles. For the most part, I've been sinking a great deal of $ for service, but love the car. It still rides great and functions as it should. However, after the Tesla mobile service replaced my 12v battery replaced after it died on my unexpectantly without any warning, I now get the "maximum battery charge level" message but here is the thing. Its sporadic. Sometimes I can trigger this message by going up a sharp hill and a few minutes later, it goes away. When the message is active, I can't charge past 70 miles. When it goes away, I can charge it fully.

Is this normal? Could it be a short or bad connection? Or is it simply time to get rid of the car?

Thanks Everyone!

Wow, that’s a beautiful car!

 

[NewbyMaybe]

There's a chance that water has accumulated in the battery bank or under the charge port and an incline is moving the water. But it's more likely the age of the battery.

 

[Hitmakr7]

Have you gotten any BMS_u029 or BMS_u018 alerts? Did you do a recent software update?

I've not received any of these alerts in a warning format... What I mean is when entering into service mode, I saw them there.

 

[Hitmakr7]

Wow, that’s a beautiful car!

Thanks! I hate I may have to get rid of it. Local trade is only offering $8k for it. :-( The car has been babied by myself the the previous owner. The inside looks like new.

 

[Hitmakr7]

There's a chance that water has accumulated in the battery bank or under the charge port and an incline is moving the water. But it's more likely the age of the battery.

Does that mean that its totally trashed? Or just need to dry out? I've driven it another 200 miles without issue now.

 

[dwbv]

Are you able to check the mobile tech's work? Maybe he undid something and didn't tighten it back properly? Something may just be loose? Something was tripped over during the install?

I'm not blaming the tech and it may be worth a check.

 

[goodbadboys9]

Main battery needs to be replaced & you can’t easily dry it out

 

[NV Ray]

I've not received any of these alerts in a warning format... What I mean is when entering into service mode, I saw them there.

I put this FAQ together on those alerts. https://docs.google.com/document/d/...ouid=101367879314455822316&rtpof=true&sd=true

 

[NewbyMaybe]

If dry weather seems to help then it's a good sign the charge port may be shorting, taillight needs to be removed to check it. If water is trapped in the battery then it's smarter to replace it due to age.
If there's an independent EV garage in your area they might help but only temporarily and without much of a warranty.

 

[NewbyMaybe]

If it happens in cold weather then it could be the battery heater.

 

[NewbyMaybe]

Worst part about it is the car could be warning you that a total shutdown will leave you stuck in traffic.

 

[Hitmakr7]

You guys wouldn't believe how I solved the issue..... It was PUMP 2. It failed. After replacing the pump, the car has been operating like a dream. Go figure.......

 

[Kdewalt10]

What’s PUMP2?

 

[NV Ray]

You guys wouldn't believe how I solved the issue..... It was PUMP 2. It failed. After replacing the pump, the car has been operating like a dream. Go figure.......

Thanks for the update. Who diagnosed the solution? Your Tesla Service Center?

Also, to be clear for the members of Tesla BMS_u029/BMS_u018 | Facebook did you get either the BMS_u029 or BMS_u018 alert? In your post #6 you seem to say yes.

 

[dwbv]

You guys wouldn't believe how I solved the issue..... It was PUMP 2. It failed. After replacing the pump, the car has been operating like a dream. Go figure.......

So the car wasn't able to confirm that it could warm up the battery properly therefore it limited charging to 70 miles max. When the pump was working, the car was able to confirm it could warm the battery then all was good.

Is this correct?

 

[maximizese]

Glad you found a solution and I hope it holds up. I googled "Tesla Model S Pump 2" and found some sites about the schematics and removal/install instructions:

Battery Coolant Pump 2 (Remove and Replace)

Would you care to describe how you came to learn that your coolant pump 2 was the problem? I'm assuming Service Mode listed the fault.

 

[Hitmakr7]

Sorry about the delay.... I learned about the Pump 2 replacement from a well respected guy who lives in Pensacola FL who I consider to be the most knowledgeable Tesla guru who never worked at Tesla. He jumped on the Tesla wave really early and owns every model including a few non-Tesla electric vehicles.

Although it was listed as a fault, he threw out this issue well before I sent him an image of the error log.


@dwbv - You are correct.

@NV Ray - The guy in Pensacola FL told me to check for the error. Tesla service center immediately said that I needed to replace the battery even after reviewing the vehicle after taking it in. :-(

@Kdewalt10 - For my vehicle, after removing the frunk lining, it was the pump found in the center of the vehicle. After cutting the power, it took less than 15 minutes to replace.

@maximizese - The same as mentioned above. The contact in Florida told me to look for the fault while in Service Mode.


To all of you who've responded and commented, I wish that one day I could put together a gathering and treat you guys. All of you are amazing and I really appreciate you taking the time to respond.