Model S/X 100 kWh: voltage sense harness tab failures
Contents
Symptoms
- BMS_w107/BMS_f107 errors and related sensor/measurement circuit codes.
- Inability to charge/drive, mismatch between total voltage and the "sum by bricks".
Why it happens
In V2 100-kWh packs, thin contact "tabs"/harnesses are used to read voltage from cell groups. Due to vibrations, thermal cycling, or impact, contacts can detach → the BMS loses correct readings.
Solutions
- Diagnostics of modules, finding the defective harness.
- Restoration/resoldering/replacement of the harness (difficult and requires experience).
- With multiple detachments, module or pack replacement.
Cost (Minsk shop prices)
- Removal/diagnostics/local repair: ≈ $1 000–3 000 (more often ~$2 000).
Links
- V2 harness repair overview: https://sites.google.com/view/teslahvbattery/the-repair/v2-pack-sense-wire-repair
- "Voltage Sense Harness" discussion: https://www.reddit.com/r/TeslaModelS/comments/1fymqev/voltage_sense_harness/
- Examples of BMS errors: https://teslamotorsclub.com/tmc/threads/tesla-model-s-2014-hv-battery-issue.284018/page-4
- Fixing the voltage sense harness on a 2019 Model S (TMC): https://teslamotorsclub.com/tmc/threads/fixing-voltage-sense-harness-on-2019-model-s.350143/
Sources
- https://sites.google.com/view/teslahvbattery/the-repair/v2-pack-sense-wire-repair
- https://www.reddit.com/r/TeslaModelS/comments/1fymqev/voltage_sense_harness/
- https://teslamotorsclub.com/tmc/threads/tesla-model-s-2014-hv-battery-issue.284018/page-4
- https://teslamotorsclub.com/tmc/threads/fixing-voltage-sense-harness-on-2019-model-s.350143/
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