What it means
A general open-circuit fault on the third EGR valve C control - typically a third EGR loop in heavy-duty engines or specific Euro-7 systems.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
EGR valve C controls exhaust-gas recirculation through the C stage or loop, where that system is fitted. The module monitors the valve's control circuit and sets this code when the circuit is open, such as from a broken wire, poor connector contact, or an internal connection failure.
Common causes
Most likely first.
- Open in valve or wiring
- Pin pushed back out of connector body
- Cracked solder joint inside the module or sensor
Symptoms
- Check engine light
- Possible rough idle, hesitation, or reduced power
- Increased emissions or failed emissions test
How to diagnose it
- Save freeze-frame data and scan for related EGR codes to see when the valve C circuit fault occurred and whether other EGR stages are affected.
- Inspect the EGR valve C connector for a pushed-back pin, corrosion, or a connector that is not fully seated.
- Trace the valve C control wiring for breaks, abrasion, heat damage, or a disconnected section.
- Check circuit continuity through the valve C control wire and connector with power isolated as directed by the manufacturer.
- If the external circuit is intact, check the valve C actuator and module connections for an internal open using the manufacturer's diagnostic procedure.
Common fixes
- Reconnect the EGR valve C connector securely.
- Repair a broken or damaged section of valve C control wiring.
- Repair or replace a connector terminal that has backed out or lost contact.
- Repair the valve C actuator or module connection if testing confirms an internal open.
Can I keep driving?
A short trip may be possible if the engine runs normally, but avoid heavy loads if power is reduced or the engine hesitates. The open EGR C circuit can increase emissions and may cause a failed emissions test.
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.