Powertrain, generic · Hybrid propulsion

P0B4B Hybrid/EV Battery Voltage Sense D Circuit Range/Performance

Check engine lightOn

EmissionsRelevant

Drive cycleNot required

Limp modePossible

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.

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Outdated battery controller software (Chrysler Pacifica PHEV)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

Symptoms

MIL, often after several drives
Limited hybrid assist or electric range

Repair estimate

DifficultyShop_onlyWorkshop job

Parts and labour€50–6,000

Time0.2–8 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

hv battery voltage sense dwiring harnessbms

References: gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com, static.nhtsa.gov.