P0E79

Coolant Bypass Valve A Control Stuck/Open

Severity

⚠️ Medium

Can you drive?

Yes, but get it checked soon

Approx. repair cost

$17–56 (est.)

Symptoms

Unstable engine temperature
Poor interior heating
Extended engine warm-up time
Check Engine light comes on
Possible errors in related systems

Causes

Stuck coolant valve
Open or short circuit in control circuit
Problems with the engine control unit
Valve contaminated or corroded
Valve solenoid malfunction

How to Fix

Check valve electrical circuit
Test the resistance of the electromagnet winding
Clean or replace coolant valve
Check thermostat operation
Reset error and test drive

Related codes

P0E78 P0E80 P0128