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P25FF

Electrical System Voltage Stabilizer Control Module Performance

The voltage stabiliser module (DC/DC converter for stop-start engine cranking events) does not maintain the regulated 12 V output during high transient loads. Sensitive electronics may reset during cranking.

  • Check engine light: Yes
  • Emissions related: No
  • Repair difficulty: medium

Common causes

Ordered by how often each turns out to be the cause.

  • Aged smoothing capacitors lose capacitanceCommon
  • Battery condition causes input voltage to drop too farPossible
  • Internal fault in the converter switching stagePossible

Parts involved

  • Voltage Stabilizer Module
  • Dc Dc Converter

P25FF is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.