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.
High severity. Can I keep driving?If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.
Symptoms
- MIL, often after several drives
- Limited hybrid assist or electric range
Most likely causes
- Outdated battery controller software (Chrysler Pacifica PHEV)
- Block or cell voltage measurement drifting away from the pack voltage
- Measuring input of channel D frozen at a constant value
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- It can trigger limp mode.
- It affects emissions.
What each character of P0B4B means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- B: Subsystem depends on the code range
- 4B: Specific fault in that system
Frequently asked questions
Can I keep driving with code P0B4B?
If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.
What causes code P0B4B?
The most common causes are: outdated battery controller software (Chrysler Pacifica PHEV); block or cell voltage measurement drifting away from the pack voltage; measuring input of channel D frozen at a constant value.
Related codes
- P0B4AHybrid/EV Battery Voltage Sense D Circuit
- P0B4CHybrid/EV Battery Voltage Sense D Circuit Low
- P0B4DHybrid/EV Battery Voltage Sense D Circuit High
- P0B4EHybrid/EV Battery Voltage Sense D Circuit Intermittent/Erratic
- P0B46Hybrid/EV Battery Voltage Sense C Circuit Range/Performance
- P0B50Hybrid/EV Battery Voltage Sense E Circuit Range/Performance
- P0ABBHybrid/EV Battery Pack Voltage Sense A Circuit Range/Performance
Sources
- gsi.ext.gm.com: 12OBDG06 Hybrid Diagnostics
- gsi.ext.gm.com: 16OBDG01 Hybrid Diagnostics
- gsi.ext.gm.com: 19OBDG01 Hybrid Diagnostics
- static.nhtsa.gov: MC 10218553 9999
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.