P0B52: Hybrid/EV Battery Voltage Sense E Circuit High

The threshold behind P0B52 is chosen so that only a measurement error can reach it. A lithium-ion cell is fully charged at roughly 4.2 V, yet GM's battery energy control module waits for 4.8 V or more on channel E, for 1.4 s within 2 s, before storing the code as Type A, one trip. On the nickel-metal hydride packs of the 2012 two-mode trucks and SUVs the corresponding limit is 23 V for block 5, confirmed in 15 of 20 samples and stored as Type B. Since a false high reading could make the controller stop charging early or misjudge balancing, power and charging are restricted. Real overvoltage of a cell is reported by its own cell voltage codes.

Symptoms

• Charging stops early or is refused
• MIL and reduced battery power
• Shorter electric range

Most likely causes

• Channel E sense line contacting a higher cell tap
• Faulty measuring input or reference in the monitoring module

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. Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
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 P0B52 means

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

Frequently asked questions

Can I keep driving with code P0B52?

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 P0B52?

The most common causes are: channel E sense line contacting a higher cell tap; faulty measuring input or reference in the monitoring module.

Related codes

• P0B4FHybrid/EV Battery Voltage Sense E Circuit
• P0B50Hybrid/EV Battery Voltage Sense E Circuit Range/Performance
• P0B51Hybrid/EV Battery Voltage Sense E Circuit Low
• P0B53Hybrid/EV Battery Voltage Sense E Circuit Intermittent/Erratic
• P0B4DHybrid/EV Battery Voltage Sense D Circuit High
• P0B57Hybrid/EV Battery Voltage Sense F Circuit High

Sources

• gsi.ext.gm.com: 19OBDG01 Hybrid Diagnostics
• gsi.ext.gm.com: 12OBDG06 Hybrid Diagnostics
• 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.