P0B4BHybrid/EV Battery Voltage Sense D 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
- How the plausibility of channel D is judged depends on the pack. On the 2012 GM two-mode hybrids the battery pack control module multiplies block 4 by 20 and compares it with the pack voltage; a gap above 70 V in 160 of 170 samples sets P0B4B, Type B, two trips. Later lithium-ion packs compare movement instead: in the 2016 Cadillac ELR channel D must move with the average cell voltage, checked every 200 ms with 20 failures in 40 samples, Type A, and the 2019 tables use 35 of 40 samples. Chrysler lists the code as Voltage Sense 4 Circuit Performance on the 2020 Pacifica plug-in hybrid and fixes it with BPCM software. Separate codes cover open, low and high faults.
- What you may notice
- MIL, often after several drives
- Limited hybrid assist or electric range
- Likely causes
- PossibleOutdated battery controller software (Chrysler Pacifica PHEV)
- PossibleBlock or cell voltage measurement drifting away from the pack voltage
- PossibleMeasuring input of channel D frozen at a constant value
- 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 – €6,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.