P0B4B code meaning
Hybrid/EV Battery Voltage Sense D Circuit Range/Performance
Powertrain system Generic code P0Bxx codes Check engine light
What P0B4B means
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.
P0B4B at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor0.2 to 8 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0B4B
- MIL, often after several drives
- Limited hybrid assist or electric range
Common causes of P0B4B
- 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
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Hv battery voltage sense dWiring harnessBms
What each part of P0B4B means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| B | Area: hybrid propulsion. |
| 4B | The exact fault in that area. |
What to do next
- Note P0B4B and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0B4B
What does P0B4B mean?
P0B4B means "Hybrid/EV Battery Voltage Sense D Circuit Range/Performance". How the plausibility of channel D is judged depends on the pack. It is a generic code, so it means the same on every make.
Is it safe to drive with P0B4B?
Drive gently and only to a workshop. With P0B4B the car can go into limp mode (reduced power) to protect itself.
Will P0B4B fail an emissions test?
Yes, it can. P0B4B is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0B4B to fix?
Difficulty: workshop only. A typical repair takes 0.2 to 8 hours of work. This is a job for a workshop.
Will P0B4B clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.