What it means
Voltage on the third bypass valve control line is above the expected window. Typical causes are a short to battery or an open solenoid coil.
At a glance
- Usually lights the check-engine light
How it works
This code concerns the control circuit for turbocharger or supercharger bypass valve C. The module sees voltage above the expected range, which can happen if the control wire is shorted to battery voltage or the valve's solenoid coil is open.
Common causes
Most likely first.
- Control wire shorted to a B+ supply
- Open solenoid coil
- Connector pins corroded - high contact resistance
Symptoms
- Reduced engine power or boost
- Sluggish acceleration
- Check-engine light may illuminate
How to diagnose it
- Record freeze-frame data and check live data or a commanded test for bypass valve C to see when the high circuit reading appears.
- Inspect valve C's connector and harness for corrosion, loose terminals, damaged insulation, or a control wire touching a B+ supply.
- Check the valve C solenoid coil for an open circuit using the manufacturer's procedure and specification.
- Test the control wire for a short to battery voltage and check continuity between the valve and module connectors.
- If the valve and wiring pass, verify the module's output and control using the vehicle maker's test procedure.
Common fixes
- Clean and secure corroded or loose bypass valve C connector terminals.
- Repair a control wire shorted to B+ or damaged harness insulation.
- Replace bypass valve C if its solenoid coil is open.
- Repair a confirmed module-side circuit fault after checking the valve and wiring.
Can I keep driving?
Reduced boost may make acceleration sluggish, so avoid hard acceleration and plan for slower merging or overtaking. Stop if power loss becomes severe, or if smoke or unusual intake noise develops.
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.