What are the common causes of P0EA7?

Low coolant or air in the auxiliary cooling loop. A failed auxiliary coolant pump. A restricted auxiliary radiator or hose. A stuck auxiliary cooling bypass valve.

Read auxiliary cooling system temperature on a scan tool. Check the auxiliary coolant level and bleed the loop. Command the auxiliary coolant pump and confirm flow. Inspect the auxiliary radiator and hoses for restriction. Test the bypass valve if flow is still wrong. Clear the code and retest.

P0EA7

Auxiliary Cooling System Performance

System: Powertrain control (P code)
Lamp: Check Engine Light
Category: Powertrain - Hybrid Propulsion

What it means

P0EA7 means Auxiliary Cooling System Performance.

Check these first

Low coolant or air in the auxiliary cooling loop
A failed auxiliary coolant pump
A restricted auxiliary radiator or hose
A stuck auxiliary cooling bypass valve

What to do next

Read auxiliary cooling system temperature on a scan tool
Check the auxiliary coolant level and bleed the loop
Command the auxiliary coolant pump and confirm flow
Inspect the auxiliary radiator and hoses for restriction
Test the bypass valve if flow is still wrong
Clear the code and retest

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Updated

Generic SAE J2012 definition. Last updated 2026-10-10.