P0B44Hybrid/EV Battery Voltage Sense B 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
- P0B44 is the J2012 slot for a cell voltage channel B whose reading jumps or drops out for short moments rather than failing permanently. No manufacturer documents P0B44 publicly. For orientation, GM's 2019 tables check channel B for open sense lines (P0B40), frozen values compared with the other cells (P0B41) and fixed limits of 0.2 V and 4.8 V (P0B42, P0B43); an erratic monitor would add a test for implausible steps between samples. CARB requires the storage system's voltage sensors to be monitored as inputs and faults to be pinpointed to the smallest replaceable unit. Typical causes are vibration-loosened cell taps and connectors on the monitoring board. Warnings may come and go with driving conditions.
- What you may notice
- MIL or hybrid warning that comes and goes
- Occasional loss of electric drive or assist
- Likely causes
- LikelyLoose or cracked cell tap connection
- PossibleFretting or vibration damage at the monitoring board connector
- PossibleElectrical noise from inverter or motor coupling into the sense lines
- 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 – €6,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.