I've had the SERV light intermittently come on for the last month or so, and have been trying to diagnose the problem. The symptom is the SERV light illuminating along with a slight but noticeable decrease in available power. It typically happens within about 5 minutes of starting out, and sometimes goes out on it's own but mostly stays on until the end of the trip. It's always not illuminated on restart of the car.
I swapped the 12V battery today (didn't think that was the problem but wanted to rule it out). Gave it a good charge and the problem is still present.
Digging a bit deeper I reset all the profiles (I have OVMS v3), looked at various logs and still had the problem. I started to see a pattern where is *seems* to happen shortly after a reasonably (>5-10s) period of regen (so, say, deceleration from 40mph to 20mph).
I also noticed that the latest OVMS firmware is 25th Sep, and while I can't say for definite it was *around* this time that I started seeing the problem. (I'm running 3.2.005-42-g0e8f7306/ota_1/main (build idf v3.3-beta3-774-g6652269e1 Sep 25 2019 18:38:03))
So I disabled CAN writes in OVMS, and it seems to have fixed the issue. I've only done one drive since, but it was quite long and the SERV light stayed off the whole time - I haven't been able to do that for quite a few weeks.
So, is there anything in the latest firmware that could cause a SERV issue after a bit of regen? I have got the "Enable Auto Power Adjustment" ticked and Kickdown enabled.
Happy to re-enable CAN writes and grab logs etc if they'd help (just let me know what you need).