P0B52Hybrid/EV Battery Voltage Sense E Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- 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.
- What you may notice
- Charging stops early or is refused
- MIL and reduced battery power
- Shorter electric range
- Likely causes
- LikelyChannel E sense line contacting a higher cell tap
- PossibleFaulty measuring input or reference in the monitoring module
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €50 – €5,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.