What it means
Bypass valve B control voltage above expected range. Boost control tracks commanded vs. actual manifold pressure; persistent deviation means wastegate, vanes, hose or actuator are not delivering the requested pressure.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Bypass valve B controls airflow around a turbocharger or supercharger compressor, and the control module monitors the electrical circuit that operates it. P00C2 sets when the valve B control voltage is above the expected range, which can result from a short to battery voltage or another excessive-voltage fault. It identifies a high electrical condition rather than a general boost-pressure error.
Common causes
Most likely first.
- Wiring shorted to battery
- Connector pins corroded - high contact resistance
- Supply wire pinched against B+ source
Symptoms
- Charge status indicator shows fault
- Charging may not start or interrupts
- Slower-than-expected charge rate
How to diagnose it
- Read freeze-frame data and related codes to confirm the fault concerns bypass valve B's high control voltage.
- Locate valve B and inspect its harness for pinching or chafing against a power source, and look for wiring repairs that may have crossed circuits.
- Check valve B's connector for corrosion, loose pins, moisture, or terminal damage that could disrupt the control signal.
- Measure the valve B control circuit for an unintended connection to battery voltage using the manufacturer's specification.
- If no wiring fault is found, test the actuator and module control circuit according to the manufacturer's procedure.
Common fixes
- Repair a pinched or damaged valve B wire shorted to a power source.
- Correct connector terminal damage or corrosion affecting the control circuit.
- Replace a bypass valve B solenoid or actuator if testing confirms an internal electrical fault.
- Repair a confirmed module-side control-circuit fault.
Can I keep driving?
Drive gently and avoid sustained high boost until the electrical fault is corrected, because valve B may not regulate airflow as commanded. Stop if power becomes unpredictable or the forced-induction system makes unusual noises.
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.