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

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.

Symptoms

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

Most 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

What to check, in order

Start with the simplest. You can tick off each step.

1. Read the codes with a hybrid-compatible scanner and write down the freeze frame data
2. Compare the reading with other engine data while varying the engine speed.
3. Make sure the battery cooling air intake is clean
4. Check the 12 V auxiliary battery, which can also trigger warnings
5. Leave any high-voltage measurements to a specialized repair shop

Good to know

• It can trigger limp mode.
• It affects emissions.

What each character of P0B41 means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• B: Subsystem depends on the code range
• 41: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0B41?

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 P0B41?

The most common causes are: 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.

Related codes

• P0B40Hybrid/EV Battery Voltage Sense B Circuit
• P0B42Hybrid/EV Battery Voltage Sense B Circuit Low
• P0B43Hybrid/EV Battery Voltage Sense B Circuit High
• P0B44Hybrid/EV Battery Voltage Sense B Circuit Intermittent/Erratic
• P0B3CHybrid/EV Battery Voltage Sense A Circuit Range/Performance
• P0B46Hybrid/EV Battery Voltage Sense C Circuit Range/Performance

Sources

• gsi.ext.gm.com: 19OBDG01 Hybrid Diagnostics
• static.nhtsa.gov: MC 10218553 9999
• law.cornell.edu: 13 CCR 1968.2

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.