What it means
The control circuit voltage for coolant bypass valve B is higher than expected. The module sets this code when it detects high voltage in the monitored circuit.
How it works
Coolant bypass valve B directs coolant through or around a thermal-management path. The module monitors voltage in valve B’s control circuit and sets P0E7D when it is higher than expected, which can result from a wire shorted to voltage, a connector fault, an actuator fault, or a module driver problem.
Common causes
Most likely first.
- Short to voltage in valve wiring
- Faulty bypass valve actuator
- Loose or corroded connector
- Failed control module driver
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 inspect live valve B command, circuit voltage or status, and coolant temperatures to establish when the high condition occurs.
- Inspect valve B’s connector and harness for damaged insulation, loose or corroded pins, moisture, or contact with a power wire.
- Use the wiring diagram to check the relevant fuse and trace accessible wiring for an unintended connection to voltage.
- Following the manufacturer’s isolation procedure, test valve B’s control wire for a short to voltage and check terminal condition.
- Test the actuator and module driver according to the manufacturer’s procedure if the wiring does not explain the high circuit reading.
Common fixes
- Repair wiring shorted to a power feed and secure the harness.
- Clean or replace corroded connector terminals and restore the seal.
- Repair loose or damaged valve B wiring.
- Replace valve B if its actuator fails the manufacturer’s test.
- Repair the control module driver only if testing confirms the driver fault.
Can I keep driving?
Avoid heavy driving if reduced power or a battery or motor temperature warning is present, because valve B’s coolant control may be impaired. Stop safely if a temperature warning appears or power falls 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.