P0B8AHybrid/EV Battery Voltage Sense P Circuit Intermittent/Erratic
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P0B8A is the erratic-signal member of the channel P group. There is no public manufacturer documentation for it: GM describes open, rationality, low and high diagnostics for sense P in its 2016 and 2019 tables, but none for an intermittent signal, and the Ford bulletins stop at channel N. The code exists because CARB 1968.2 requires the voltage sensors of a hybrid battery to be monitored and malfunctions to be stored under distinct codes. If set, the picture would be a channel P value that briefly drops out or spikes, for instance through a fatigued wire near a bend in the sense harness or a connector that loses contact when the pack warms up. Readings in live data may look normal between the events.
- What you may notice
- Warning lamp that goes out again
- Occasional engine start without demand on hybrids
- Likely causes
- LikelyFatigued wire at a bend of the sense harness
- PossibleConnector losing contact as the pack warms up
- RareSporadic fault in the cell monitoring chip
- 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.