P0B5BHybrid/EV Battery Voltage Sense G Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- When P0B5B appears, the battery controller has seen cell sense channel G at a level no usable cell would show, and it shuts down or restricts electric operation to stay on the safe side. GM documents the trigger for its lithium-ion systems as cell voltage G at or below 0.2 V for 1.4 s in a 2 s window, Type A, with the test held off while communication, open line or balancing faults are active. On the 2012 two-mode hybrids channel G is block 7, and the code needs blocks 7 and 8 together under 2 V in 15 of 20 samples, Type B. Sense wiring, connector pins and the monitoring input deserve attention before the cells, which have their own cell voltage codes.
- What you may notice
- Hybrid system warning and MIL
- Electric drive disabled or restricted
- Likely causes
- LikelyChannel G sense line shorted to a neighbouring line
- PossibleDamaged or backed-out pin in the monitoring connector
- PossibleFailed measuring input on the monitoring module
- 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: €50 – €5,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.