P0B3D: Hybrid/EV Battery Voltage Sense A Circuit Low

P0B3D sets when cell voltage channel A reads below the lowest value a real cell can have, which points to the measurement rather than the cell. GM sets it in the battery energy control module when cell voltage A is 0.2 V or less for 1.4 s within a 2 s window, Type A, one trip, provided no open sense line, communication or balancing fault is active. FCA lists P0B3D as Hybrid Battery Voltage Sense A Circuit Low on the 2019 Ram 1500 with eTorque mild hybrid, next to the pack-level code P0ABA, and cures it with a battery pack control module update. A genuinely low cell is reported with separate cell voltage codes. Expect reduced or blocked hybrid assist.

Symptoms

• MIL on
• Start-stop and electric assist unavailable
• Hybrid battery power limited

Most likely causes

• Battery pack control module software, fixed by update (Ram eTorque)
• Sense line shorted to the adjacent line or to the cell negative
• Measurement input of the cell monitoring chip failed

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. With the connector unplugged, check whether the signal wire is making contact with ground.
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 P0B3D means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• B: Subsystem depends on the code range
• 3D: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0B3D?

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 P0B3D?

The most common causes are: battery pack control module software, fixed by update (Ram eTorque); sense line shorted to the adjacent line or to the cell negative; measurement input of the cell monitoring chip failed.

Related codes

• P0B3BHybrid/EV Battery Voltage Sense A Circuit
• P0B3CHybrid/EV Battery Voltage Sense A Circuit Range/Performance
• P0B3EHybrid/EV Battery Voltage Sense A Circuit High
• P0B42Hybrid/EV Battery Voltage Sense B Circuit Low
• P0ABCHybrid/EV Battery Pack Voltage Sense A Circuit Low

Sources

• gsi.ext.gm.com: 19OBDG01 Hybrid Diagnostics
• static.nhtsa.gov: MC 10251877 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.