P0B94: Hybrid/EV Battery Voltage Sense R Circuit Intermittent/Erratic

No manufacturer documents P0B94 publicly. The code is reserved for a sense R signal that drops out or jumps for short moments instead of failing steadily. GM monitors channel R in six table sets between 2011 and 2019, but every one of those tables stops at the circuit, range, low and high monitors; an intermittent test does not appear. The legal basis is CARB 1968.2, which requires the voltage sensors of a hybrid energy storage system to be monitored like any other input and wants fault codes that point to the smallest replaceable unit. In practice such a fault would come from a connection that opens under vibration or heat, for instance a cracked crimp or a hairline crack in a flexible circuit.

Symptoms

• Warning appears and disappears between trips
• Short power reductions, normal after restart

Most likely causes

• Crimp or terminal of lead R opening under vibration
• Hairline crack in the flexible circuit carrying channel R
• Moisture or contamination in the monitoring board connector

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. Gently move the wiring with the engine running and watch whether the reading changes.
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 P0B94 means

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

Frequently asked questions

Can I keep driving with code P0B94?

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 P0B94?

The most common causes are: crimp or terminal of lead R opening under vibration; hairline crack in the flexible circuit carrying channel R; moisture or contamination in the monitoring board connector.

Related codes

• P0B90Hybrid/EV Battery Voltage Sense R Circuit
• P0B91Hybrid/EV Battery Voltage Sense R Circuit Range/Performance
• P0B92Hybrid/EV Battery Voltage Sense R Circuit Low
• P0B93Hybrid/EV Battery Voltage Sense R Circuit High
• P0B8FHybrid/EV Battery Voltage Sense Q Circuit Intermittent/Erratic
• P0B99Hybrid/EV Battery Voltage Sense S Circuit Intermittent/Erratic

Sources

• law.cornell.edu: 13 CCR 1968.2
• gsi.ext.gm.com: 19OBDG01 Hybrid Diagnostics
• gsi.ext.gm.com: 12OBDG06 Hybrid Diagnostics

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.