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P26CD

Engine Coolant Pump Control Circuit High

Voltage on the engine coolant pump control line is above the expected window. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.

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

Common causes

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

  • Control wire shorted to B+Common
  • Open motor windingPossible
  • Connector pins corroded - high contact resistanceLess likely

Parts involved

  • Engine Coolant Pump
  • Wiring Harness

P26CD 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.