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P2B5C

Engine Coolant Flow Control Valve Supply Circuit Low

The engine coolant flow control valve reports a supply circuit low condition. Coolant routing between engine and radiator branches cannot be commanded as expected.

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

Common causes

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

  • Supply fuse blownCommon
  • Open in supply wirePossible
  • Connector pins corroded - high contact resistanceLess likely

Parts involved

  • Engine Coolant Flow Control Valve
  • Wiring Harness
  • ECM

P2B5C 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.