[FREE] tCAN-Pro - TAYCAN BATTERY DIAGNOSIS FOR THE COMMUNITY

[Tooney]

Uh. Gemini and chatgpt say this scan is actually a serious danger. Could someone help confirm? Dealer is closed and I'm not sure what to do with this car...

Related forum threads by @ct14garage :
https://www.taycanforum.com/forum/t...drive-with-shorted-out-battery-modules.24793/
https://www.taycanforum.com/forum/t...-out-battery-modules-video.27737/#post-415129

Sponsored

 

[gamueller]

Uh. Gemini and chatgpt say this scan is actually a serious danger. Could someone help confirm? Dealer is closed and I'm not sure what to do with this car...

Gemini says it's a battery failure, fire risk and electrocution risk!!! (and chatgpt says similar):
This screenshot is extremely valuable. You have caught something much more serious than just "unbalanced cells."
You have data indicating a Critical High Voltage Isolation Fault.
Here is the breakdown of what this screen shows and exactly how to present it to your dealer to cut through the "unable to replicate" excuses.
The "Smoking Gun" in Your Data
Ignore the red/green blocks for a second. Look at the text list on the right side under Battery Info.
IsoRes Batt-: 1.5 kΩ (Red Flag #1)
What it means: This is the "Insulation Resistance" of the battery's negative rail.
The Spec: A healthy High Voltage system should be reading in the Megaohms (MΩ) or at least above 500 kΩ.
Your Reading: 1.5 kΩ is dangerously close to zero. This effectively means electricity is "leaking" from the battery internals to the chassis or shield.
Common Cause: In Taycans, this is the classic signature of water/coolant intrusion inside the battery pack.
Voltage Delta Δ: 0.151 V (Red Flag #2)
What it means: The difference between your highest and lowest cell voltages.
The Spec: Porsche usually considers anything over 0.050 V (50mV) as a fault requiring module replacement.
Your Reading: You are at 151mV. This is 3x the failure threshold.

At least 4 modules are Ok

 

[tacomaboy]

Related forum threads by @ct14garage :
https://www.taycanforum.com/forum/t...drive-with-shorted-out-battery-modules.24793/
https://www.taycanforum.com/forum/t...-out-battery-modules-video.27737/#post-415129

Holy shit this is terrifying.

I finally got the dealer to respond and they said have it towed in. No tow trucks available for two days. I drove it to a nearby park parking lot but I'm worried it can catch on fire or electrocute someone. I really hope I'm overreacting but I can't find any evidence to imply I shouldn't be really worried.

 

[tacomaboy]

At least 4 modules are Ok

These are the four they replaced in June.

 

[whitex]

Had 4 modules replaced in June. I have been struggling with HV electrical issues and red rings since then. The car has been in service 153 days since I have owned it (1/11/25). Thats 48% of the time!

I *JUST* got it back from service, it was there 46 days, and I test drove it and the range seems way way off (in a bad way).

Just ran the TCAN pro and this is what I see now. Can I show this to the service tech or are they going to give me shit for running the app? Its not an invasive scan, right? Do I need to try getting the battery to 0 and then charging it to 100 before I take it back? I suspect its probably toast and will be a brick in the morning. I can't express how frustrated and upset I am.

I would go a full cycle first (charge to 100%, drain it back). If you JUST got 4 modules replaced, and 4 of them show higher SoC than the rest (which is what makes the rest of them look red). When the modules are replaced, the service tech needs to charge each module as close as possible to the rest of them before installing it. unfortunately they charge to whatever the level was shown when they started the first one, possibly your battery drained a little while they were charging the 4, one at a time, as most dealers only have one jig to do this on. I also suspect the replacement procedure allows for some mismatch, as the BMS will balance it out eventually. It's probably better that the new ones are at higher SoC, as the BMS can balance them by discharging them individually once the battery is above some SoC and idle.

Bottom line, unless the car is showing you errors on the IC or PCM, just charge the battery and use the car before bringing anything up to the dealer, unless you're running up against the end of the battery warranty and want to catch it before it expires.

 

[tacomaboy]

I would go a full cycle first (charge to 100%, drain it back). If you JUST got 4 modules replaced, and 4 of them show higher SoC than the rest (which is what makes the rest of them look red). When the modules are replaced, the service tech needs to charge each module as close as possible to the rest of them before installing it. unfortunately they charge to whatever the level was shown when they started the first one, possibly your battery drained a little while they were charging the 4, one at a time, as most dealers only have one jig to do this on. I also suspect the replacement procedure allows for some mismatch, as the BMS will balance it out eventually. It's probably better that the new ones are at higher SoC, as the BMS can balance them by discharging them individually once the battery is above some SoC and idle.

Bottom line, unless the car is showing you errors on the IC or PCM, just charge the battery and use the car before bringing anything up to the dealer, unless you're running up against the end of the battery warranty and want to catch it before it expires.

Thanks! To be clear, the modules were replaced in June. It was recently in the shop to replace the power electronics modules.

 

[whitex]

Thanks! To be clear, the modules were replaced in June. It was recently in the shop to replace the power electronics modules.

I see. I'd cycle the battery first anyways (as long as the car is not showing any errors), see if the BMS will balance it out.

 

[tacomaboy]

I see. I'd cycle the battery first anyways (as long as the car is not showing any errors), see if the BMS will balance it out.

For a power cycle, AC charge only, right?

I see. I'd cycle the battery first anyways (as long as the car is not showing any errors), see if the BMS will balance it out.

Hmm, another update. It's been sitting at 20% for maybe 2 hours. I just refreshed the app and it's now down to 14% while just sitting.

 

[Hirschaj]

...
IsoRes Batt-: 1.5 kΩ (Red Flag #1)
What it means: This is the "Insulation Resistance" of the battery's negative rail.
The Spec: A healthy High Voltage system should be reading in the Megaohms (MΩ) or at least above 500 kΩ.
Your Reading: 1.5 kΩ is dangerously close to zero. This effectively means electricity is "leaking" from the battery internals to the chassis or shield.
Common Cause: In Taycans, this is the classic signature of water/coolant intrusion inside the battery pack.
...

I think AI is freaking you out for no reason. I have the same reading for "IsoRes Batt-" (it's been that way for over a year I believe) and it has not been an issue for me. I think it's quite common to have a reading in that range. I don't think anyone sees readings in the megaohms range as AI is stating to you. Definitely have your dealership check it out and let us know what they say but AI is terrible at so many things and I think it's feeding you some BS in this case. I look forward to hearing the outcome.

 

[Hirschaj]

Hmm, another update. It's been sitting at 20% for maybe 2 hours. I just refreshed the app and it's now down to 14% while just sitting.

That's definitely problematic. Maybe more bad modules.

 

[lcarron]

For a power cycle, AC charge only, right?
Hmm, another update. It's been sitting at 20% for maybe 2 hours. I just refreshed the app and it's now down to 14% while just sitting.

I have the exact same lost in 2 or more hours when the SOH is below 40%
Porsche do not want to do anything stating that this is normal operation at 50k. The overall SOH is at 83% and the warranty will not kick in.

 

[Manni55TaycanRWDplus]

Bei meinem Taycan wurde 1 neues Modul eingebaut. Nach 20TKm hat sich vom Modul nicht viel geändert. Die Spannung und der SoC des Moduls sind immer noch höher !!!!
Du musst damit leben, bis du das neue Modul den Rest anpasst. Das kann ein ganzes Jahr anhalten !!!

 

[Manni55TaycanRWDplus]

BMS arbeitet bei 100 % SOC-Anzeige

 

[thefunkygibbon]

The Taycan gateway provides the IP address

what's happened to your newer version of the app with. the paid features? thought you were ready to release it over summer?

 

[CaliPorsche]

Uh. Gemini and chatgpt say this scan is actually a serious danger. Could someone help confirm? Dealer is closed and I'm not sure what to do with this car...

I also have a 2020 4S - In my case three modules have been replaced and I get similar red and green cell mapping as you when using the tool - especially at the bottom 20% of charge. I am not an expert but when you are adding new cells among old cells it should not be a surprise to see a delta in voltage like this. I would run the rebalancing protocols listed here - effectively run down to 2% or less of charge, leave for 8 hours or so, charge to 100% with a home charger at 10-11kwh, again leave f=overnight at 100% - then use the tool to check what you see at the top and numerous points in discharge of that battery. In my case I regularly get 230-240 miles from a full charge even though the mapping shows three cells out of synch with the rest.

Sponsored