P0B27Hybrid/EV Battery B Voltage
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P0B27 is the general voltage fault of hybrid/EV battery B, the second separately monitored sub-battery or energy store. It covers a voltage that does not match expectation without saying whether it is unstable (P0B28), too low (P0B29) or too high (P0B2A). That battery B exists in production systems is shown by Stellantis, whose Jeep Wrangler 4xe bulletin lists P0B28; P0B27 itself is not documented publicly by any manufacturer. GM's analogous monitors of the whole pack are P0ABB to P0ABD, for example a pack reading more than 12 V away from the sum of the cells. CARB requires the voltage sensors and cells of hybrid storage systems to be monitored. The driver gets a hybrid warning and reduced battery power.
- What you may notice
- Hybrid/EV system or high-voltage battery warning on
- MIL on
- Battery power limited, less electric drive or assist
- Charging or recuperation restricted
- Likely causes
- PossibleWeak or failing cells or module in battery B
- PossibleFault in the voltage sense leads or connectors of battery B
- RareBattery controller software or internal measurement fault
- 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: €100 – €4,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.