What it means
The exhaust flow control valve C reports a control performance condition. Exhaust routing for back-pressure or noise control on this branch cannot be commanded reliably.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
- The engine or gearbox may go into limp mode
How it works
Exhaust flow control valve C redirects exhaust through its designated branch to help manage back-pressure or noise. The control module compares the commanded movement with the valve's response; this code sets when valve C responds more slowly than expected, often because its linkage is binding.
Common causes
Most likely first.
- Actuator response slower than calibrated
- Increased friction in valve linkage
Symptoms
- Check-engine light
- Change in exhaust sound
- Reduced engine performance
How to diagnose it
- Record freeze-frame data and check live commanded-versus-reported movement for valve C to see when its response falls behind.
- With the exhaust cool, inspect valve C's external linkage for corrosion, soot buildup, damage, or signs of binding.
- Check the actuator and valve C wiring and connector for looseness, heat damage, or corrosion that could slow actuation.
- Use a scan tool's available actuator test to command valve C through its range and observe whether movement is delayed or uneven.
- If the linkage moves freely but response remains slow, test the actuator and control circuit using the manufacturer's procedure.
Common fixes
- Clean or free up binding in valve C's linkage where appropriate.
- Repair damaged, loose, or corroded valve C wiring or connector terminals.
- Replace a faulty valve C actuator if testing confirms slow response.
- Replace the valve assembly if its mechanism remains stiff or damaged.
Can I keep driving?
If the engine runs normally and there is no severe loss of power, a short, gentle drive to arrange diagnosis may be reasonable. Avoid heavy loads; continued valve malfunction can affect exhaust back-pressure, performance, and emissions.
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.