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P2A23

Alternative Fuel Tank Shutoff Valve B Control Circuit Performance/Stuck Off

The control circuit of alternative fuel tank shutoff valve B reports a control circuit performance/stuck off condition. Tank isolation cannot be commanded as expected on multi-tank CNG/LPG systems.

  • Check engine light: Yes
  • Emissions related: Yes
  • Repair difficulty: medium

Common causes

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

  • Shutoff valve mechanically stuck closedCommon
  • Coil force degraded with agePossible
  • Carbon or debris buildup preventing free movementLess likely

Parts involved

  • Alt Fuel Tank Shutoff Valve B
  • Wiring Harness
  • Afcm

P2A23 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.