What it means
The control module detects an open circuit in the control circuit for coolant bypass valve B. It sets this code when the circuit lacks the expected electrical continuity while the valve is being monitored or commanded.
How it works
Coolant bypass valve B controls coolant routing in a thermal-management circuit, separate from valve A. The module monitors electrical continuity in valve B’s control circuit and sets P0E7B when the expected circuit path is open during monitoring or a command.
Common causes
Most likely first.
- Open or damaged valve wiring
- Loose or corroded connector
- Failed coolant bypass valve actuator
- Blown fuse or control circuit power fault
Symptoms
- Hybrid or EV warning light
- Reduced power
- Battery or motor temperature warning
- Cabin heating or cooling may be reduced
How to diagnose it
- Record freeze-frame data and check live valve B command, circuit status, and battery or motor coolant temperatures to establish when the open circuit occurred.
- Inspect valve B’s connector and harness for a loose or corroded connection, broken wire, damaged insulation, or coolant intrusion.
- Check the relevant fuse and circuit power supply against the vehicle wiring diagram before condemning the valve or module.
- Following the manufacturer’s isolation procedure, test valve B’s control-wire continuity from the valve connector toward the control module.
- Measure valve B’s actuator coil against the manufacturer’s specification; if the wire and coil pass, check the module output using the manufacturer’s procedure.
Common fixes
- Reconnect or repair a loose valve B connector.
- Repair an open or damaged valve B wire.
- Clean or replace corroded terminals and restore connector sealing.
- Replace valve B if its actuator coil is open.
- Repair a failed fuse supply or module driver only after circuit tests confirm the fault.
Can I keep driving?
If a battery or motor temperature warning, reduced power, or an EV or hybrid warning appears, limit driving because valve B may not route coolant correctly. Stop safely if a temperature warning comes on or power drops sharply.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.