What it means
The ECU detects an open circuit on the control line for the third (C) fuel pressure regulator. Either the regulator solenoid coil is internally open, the harness is broken, or the connector has lost contact - the ECU cannot drive the regulator and rail pressure cannot be controlled by this stage.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Fuel pressure regulator C is the third regulator stage identified by the vehicle's control system; its electrically controlled valve helps manage fuel pressure. This code sets when the controller detects an open in regulator C's control circuit, preventing it from commanding that stage and potentially disrupting fuel pressure.
Common causes
Most likely first.
- Open circuit in harness or connector
- Regulator solenoid winding open
- Pin pushed back out of connector body
Symptoms
- Check engine light on
- Hard start, no start, or stalling under load
- Power loss especially at high load or rpm
- Possible long cranking time
How to diagnose it
- Save freeze-frame data and check fuel pressure readings and starting or stalling conditions when the open-circuit fault occurred.
- With the ignition off, inspect regulator C's connector for a loose fit, pushed-back pin, corrosion, or water intrusion.
- Trace the regulator C harness for breaks, chafing, or damage, using the vehicle wiring diagram to identify the correct circuit.
- Test the control circuit for continuity and check the regulator solenoid winding for an open according to the manufacturer's procedure.
- If the wiring and regulator pass, test the controller's output and confirm fuel pressure behavior using the manufacturer's specifications.
Common fixes
- Reconnect regulator C's loose connector or secure a backed-out terminal.
- Repair an open or damaged wire in the regulator C control circuit.
- Replace regulator C if its solenoid winding tests open.
- Repair a faulty controller output only after confirming the circuit and regulator are sound.
Can I keep driving?
A hard-starting, stalling, or power-loss condition can make the vehicle unsafe in traffic; avoid driving if it stalls or cannot maintain speed. If it runs normally, keep any trip short and arrange diagnosis, since fuel pressure may become unreliable under load.
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.