Powertrain, generic · Hybrid propulsion

P0B41 Hybrid/EV Battery Voltage Sense B Circuit Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0B41 reports that cell voltage channel B gives values inside the normal range that fail a plausibility check against the other cells. In GM's 2019 tables Hybrid Powertrain Control Processor 2 compares sample-to-sample changes: if the average cell voltage trends by at least 0.005 V while channel B stays unchanged, a failure is counted, and 35 of 40 samples at 100 ms set the code, Type A, one trip, with system voltage above 10.2 V. FCA calls it Voltage Sense 2 Circuit Performance on the Pacifica plug-in hybrid and lists it with P0B3C and further channels in battery pack control module update bulletins. Circuit, low, high and erratic faults of channel B are P0B40, P0B42, P0B43 and P0B44.

Likely causes

Battery controller software, fixed by reprogramming (FCA Pacifica)
Cell voltage measurement channel frozen inside the monitoring electronics
High resistance in the cell sense line or its connection
Cell monitoring board failure inside the pack

Symptoms

  • MIL on, often with several voltage sense codes
  • Electric drive reduced or unavailable
  • Contactor related codes stored at the same time

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 bwiring harnessbms

Related codes

P0B40P0B42P0B43P0B44P0B3CP0B46

References: gsi.ext.gm.com, static.nhtsa.gov, law.cornell.edu.