P24DEReductant Purge Control Valve B Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- With P24DE the control line of purge valve B stays at high voltage while the controller is actually pulling it to ground to switch the valve. That points to a short to the battery feed on the wire between valve and controller, or a valve coil with too little resistance, so that the driver protects itself and the valve never shifts. No manufacturer documents P24DE publicly. For valve A, GM runs the equivalent P20A3 check while the driver is switched on (6.6 L Duramax). CARB requires heavy-duty SCR actuators to be checked for this kind of circuit fault. The consequence is the reverse of P24DD: the valve stays in dosing position, so the line is not emptied at shut-down and can freeze. Interruptions are P24DB, the functional test P24DC.
- What you may notice
- Malfunction indicator lamp on
- DEF line not purged, frozen line after frost
- Likely causes
- LikelyControl wire touching a supply line
- PossibleValve coil with shorted turns and too low resistance
- RareDamaged driver stage in the control module
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €80 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.