P0E76: Coolant Bypass Valve A Control Circuit Low

With P0E76 the voltage on the control line of coolant bypass valve A stays lower than the driver expects for its current state, which points to a short to ground somewhere in the harness or inside the actuator. What happens next depends on the driver layout: a low-side output may leave the valve energised all the time, a high-side output can no longer move it at all, and the driver may switch off to protect itself. No manufacturer documents P0E76 publicly. In Ford's 2019 hybrid summary the matching job falls to P2682, flagged once the driver has signalled a fault continuously for over 5 s; only after that does Ford run its stuck-valve check P26AB. CARB requires circuit monitoring of output devices like this one. P0E77 is the high case, P0E75 an open; P0E79 and P0E7A cover a valve that is mechanically stuck.

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

Check engine light
Valve stays in one position, heating behaves oddly
Possible blown fuse if the short is hard

Most likely causes

Chafed control wire touching body or engine ground
Internal short in the valve A actuator
Moisture bridging pins in the valve connector

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
With the connector unplugged, check whether the signal wire is making contact with ground.
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 P0E76 means

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

Frequently asked questions

Can I keep driving with code P0E76?

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 P0E76?

The most common causes are: chafed control wire touching body or engine ground; internal short in the valve A actuator; moisture bridging pins in the valve connector.

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.