What it means
The exhaust flow control valve C reports a position circuit high 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
The position sensor on exhaust flow control valve C sends the control module a signal representing valve position. This code sets when that signal is higher than the module's allowed range, which can result from a signal wire shorted to power, an open sensor, or a poor connection.
Common causes
Most likely first.
- Signal wire shorted to B+
- Open position sensor
- Connector pins corroded - high contact resistance
Symptoms
- Check-engine light
- Change in exhaust sound
- Reduced engine performance
How to diagnose it
- Record freeze-frame data and check live valve C position data for a high, fixed, or implausible reading.
- With the exhaust cool, inspect valve C's sensor connector and wiring for heat damage, corrosion, loose terminals, or contact with a power wire.
- Check the sensor's reference supply, ground, and signal circuit against the wiring diagram and manufacturer's specification.
- With the circuit isolated as directed by the manufacturer, check whether the signal wire is shorted to battery power.
- If wiring and connections pass, test the valve C position sensor for an open or failed output using the manufacturer's procedure.
Common fixes
- Repair a signal wire shorted to power or other damaged valve C sensor wiring.
- Clean and secure corroded or loose connector terminals if they remain serviceable.
- Replace the valve C position sensor if tests confirm it is open or faulty.
- Replace the valve assembly if its sensor is not separately serviceable and testing confirms the fault.
Can I keep driving?
If there is no severe power loss, drive gently only as needed to arrange diagnosis. The module may not be able to determine valve C's position, which can affect exhaust routing, 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.