P0E75: Coolant Bypass Valve A Control Circuit/Open

P0E75 is the basic electrical code for coolant bypass valve A: the control unit finds that the output switching the valve, or the wire leading to it, does not form a closed circuit, in most cases because of an open. Valves of this kind usually divert coolant between loops, for example between the engine and a heater loop that keeps the cabin warm while a hybrid drives electrically. No manufacturer documents P0E75 publicly. Ford's 2019 hybrid and plug-in summary watches a comparable valve under the older codes P2682 and P2683 and relies on the fault status of its smart driver, which must persist beyond 5 s. CARB counts such actuators among the comprehensive components that need circuit checks. Low, high and plausibility faults of this circuit are P0E76 to P0E78; drivers mostly notice weaker heating.

Symptoms

• Check engine light
• Little or no cabin heat, especially in electric mode
• Engine warms up more slowly or runs more often than usual

Most likely causes

• Broken wire or loose connector on the valve A control circuit
• Burnt or internally open coil/motor in valve A
• Coolant or water ingress corroding the valve connector pins
• Faulty output driver in the engine or hybrid control module

What to check, in order

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

1. With the engine cold, check the coolant level; never do this when the system is hot
2. Check the continuity of the wire between the component and the control module.
3. Check the actual temperature in live data
4. Make sure the fan comes on when it should
5. Check the thermostat and connector
6. 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 P0E75 means

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

Frequently asked questions

Can I keep driving with code P0E75?

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 P0E75?

The most common causes are: broken wire or loose connector on the valve A control circuit; burnt or internally open coil/motor in valve A; coolant or water ingress corroding the valve connector pins.

Related codes

• P0E76Coolant Bypass Valve A Control Circuit Low
• P0E77Coolant Bypass Valve A Control Circuit High
• P0E78Coolant Bypass Valve A Control Circuit Range/Performance
• P0E7BCoolant Bypass Valve B Control Circuit/Open
• P2682Engine Coolant Bypass Valve A Control Circuit Low

Sources

• fordservicecontent.com: OBDSM1901 HEV
• law.cornell.edu: 13 CCR 1968.2

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.