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P2CF9

Belt Integrated Starter Generator Belt Tensioner Control Circuit/Open

The control circuit of the belt-integrated starter/generator (BISG) belt tensioner reports a control circuit/open condition. Belt tension cannot be modulated for assist/regen modes.

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

Common causes

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

  • Open in tensioner control wireCommon
  • Open tensioner actuatorPossible
  • Pin pushed back out of connector bodyLess likely

Parts involved

  • Bisg Belt Tensioner
  • Wiring Harness
  • Hybrid Control Module

P2CF9 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.