Powertrain, generic · Hybrid propulsion

P0B23 Hybrid/EV Battery A Voltage

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0B23 is the general fault for the voltage of hybrid/EV battery A, the first of up to four sub-batteries or energy stores (A to D) that the battery controller evaluates separately; which physical unit carries the letter is up to the manufacturer. The code says that the measured voltage of this unit no longer fits the expected value, without the finer split into unstable (P0B24), low (P0B25) or high (P0B26). No manufacturer documents P0B23 publicly; Bentley and Stellantis bulletins only show the specific siblings. GM watches the comparable whole-pack voltage with P0ABB to P0ABD. CARB requires the voltage sensors and cells of the hybrid storage to be monitored, with fault codes that point to the smallest replaceable unit.

Likely causes

Weak or failing cells or module in battery A
Fault in the voltage sense leads or connectors of battery A
Battery controller software or internal measurement fault

Symptoms

  • Hybrid/EV system or high-voltage battery warning on
  • MIL on
  • Battery power limited, less electric drive or assist
  • Charging or recuperation restricted

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€100–4,000
Time1–10 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

hv battery abms

Related codes

P0B24P0B25P0B26P0B27P0B2BP0B2FP0ABB

References: law.cornell.edu, gsi.ext.gm.com.