What it means
The LDP switching valve is stuck in the activated position. The evaporative system captures fuel vapor from the tank and purges it into intake; leaks or stuck purge valves leak hydrocarbons and cause emissions failures.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The leak detection pump switching valve changes the pump's airflow path during EVAP leak testing. P24C0 sets when the module detects that the valve remains activated when it should release, indicating a stuck-on valve or a fault preventing it from returning.
Common causes
Most likely first.
- Valve stuck on
- Carbon or debris buildup preventing free movement
- Component wear with age - mechanical play
Symptoms
- Check engine light on
- Possible smell of fuel near tank or engine bay
- Failed emissions inspection
- Loose-cap warning may appear
How to diagnose it
- Save freeze-frame data and review live EVAP test and valve-command information to confirm when the valve was expected to switch off.
- Inspect the switching valve and its connector for damage, contamination, corrosion, or wiring that could keep the valve energized.
- Use a scan tool's supported output test to command the valve on and off, and observe whether its response follows the command.
- Check the valve control circuit for a short to supply or a module output that remains active, following the wiring diagram and manufacturer's procedure.
- If the electrical command releases correctly, inspect or test the valve for binding or debris according to the manufacturer's service information.
Common fixes
- Repair a control wire short that keeps the valve energized.
- Clean or repair a contaminated or sticking valve if the manufacturer's service procedure allows it.
- Repair damaged connector terminals or wiring.
- Replace the switching valve if it remains activated despite correct electrical control.
Can I keep driving?
The vehicle is typically driveable, but the EVAP leak test may fail and emissions compliance can be affected. Avoid delaying diagnosis if you smell fuel vapour around the vehicle.
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.