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P0EA9

Auxiliary Cooling System Performance

The auxiliary cooling system performance is below calibration. Coolant flow or temperature drop insufficient under load.

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

Common causes

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

  • Aux pump output degradedCommon
  • Radiator partially blockedPossible

Parts involved

  • Aux Cooling Pump
  • Aux Cooling Radiator
  • Aux Cooling Fan

P0EA9 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.