What does this code mean?
The wording below belongs to the named make and communication. Match the complete code, reporting module, model year and engine before applying it.
A code identifies a detected condition, not a part that must automatically be replaced.
Manufacturer communications
1Original wording in English
BUICK, CADILLAC, CHEVROLET, PONTIAC
Reported code forms P0400
SOME CUSTOMERS MAY EXPERIENCE A FAILURE OF THE EXHAUST GAS RECIRCULATION (EGR) VALVE DUE TO CORROSION OF THE INTERNAL DIAPHRAGM PLATE, LEADING TO DRIVEABILITY COMPLAINTS OF A CHECK ENGINE LIGHT FOR EGR VALVE (DTC…
Check vehicle applicability
1A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
Historical vehicle association; OBD-II compatibility is not established by this record.
| Make | Model | Model year |
|---|---|---|
| Buick | ROADMASTER | 1996 |
Historical records · 1 · Historical vehicle association; OBD-II compatibility is not established by this record.
Before replacing a part
Record codes and freeze-frame data. Check battery condition, related codes and visible wiring or hose damage. Follow the vehicle's diagnostic procedure and test results before replacing parts.
Can I keep driving?
A code alone cannot establish whether driving is safe. A flashing malfunction light, severe shaking, overheating, oil-pressure warning or loss of braking or steering needs prompt attention. Stop in a safe place and seek assistance when control or engine safety is affected. Follow the vehicle handbook.