P0BAAHybrid/EV Battery Voltage Sense W Circuit Range/Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- Here the W reading is not missing but implausible: it fails to follow the rest of the pack. GM's 2019 hybrid powertrain control processor 2 watches for the average cell voltage to move more than 0.022 V between samples and then expects channel W to trend at least 0.005 V in the same direction; 35 failures in 40 samples at 100 ms give a Type A fault. The 16OBDG02 programme applies the same logic with 0.002 V. The eAssist system is more tolerant and only asks the cell to move half as far as the others once the average shifts more than 0.045 V, 20 of 40 samples, Type B. In the 2011 Volt tables W appears as sensor 23 of the rationality check. Drivers often notice nothing beyond the warning lamp.
- What you may notice
- Warning lamp with little change in driving
- Possibly limited regeneration or electric assist
- Likely causes
- LikelyMeasuring input for W frozen at a fixed value
- PossibleBattery controller software needing an update
- RareCell W reacting differently to load because of ageing
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €80 – €5,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.