P0E7A: Coolant Bypass Valve A Control Stuck Closed

P0E7A is the reverse of P0E79: valve A should open and let coolant pass, but the temperature picture says it has stayed shut. Depending on what the valve connects, the result is a loop that gets no flow from the engine side, so heater output or heat transfer drops, or a branch that heats up because it is cut off from circulation. No manufacturer documents P0E7A publicly. The closest published case is the sibling on valve B: Stellantis sets P0E80 once the engine coolant reading and the electric heater inlet are over 40 °F apart, and blames misrouted hoses or a clogged three-way valve on Wrangler and Pacifica plug-in hybrids. Under CARB, actuators of this kind need a functional check as well. Electrical faults on valve A are P0E75 to P0E78.

Medium severity. Can I keep driving?Watch the temperature gauge. If it climbs or a warning appears, stop the car in a safe place and turn off the engine: overheating can cause serious damage.

Symptoms

Little or no cabin heat
Rising coolant temperature in the affected loop
Check engine light

Most likely causes

Debris or deposits blocking valve A
Actuator or gear stuck in the closed position
Air pocket after a coolant service blocking flow

What to check, in order

Start with the simplest. You can tick off each step.

With the engine cold, check the coolant level; never do this when the system is hot
Use the scanner to command the movement and compare the actual position with the requested one.
Check the actual temperature in live data
Make sure the fan comes on when it should
Check the thermostat and connector
Measure the sensor and replace it if its readings do not make sense

Good to know

Repair difficulty: medium
It affects emissions.

What each character of P0E7A means

P: Powertrain: engine and transmission
0: Generic code: same on every make
E: Subsystem depends on the code range
7A: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0E7A?

Watch the temperature gauge. If it climbs or a warning appears, stop the car in a safe place and turn off the engine: overheating can cause serious damage.

What causes code P0E7A?

The most common causes are: debris or deposits blocking valve A; actuator or gear stuck in the closed position; air pocket after a coolant service blocking flow.

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.