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
2Original wording in English
CHEVROLET, GMC
Reported code forms P0421
18209 - Service Update. Certain vehicles equipped with a 1.6L diesel engine (RPO LH7), may have been built with an improper alignment of the clamp/gasket assembly connecting the turbocharger to the catalytic converter.…
CHEVROLET, GMC
Reported code forms P0421
This technical bulletin provides a procedure to reposition the exhaust clamp to correct a condition of Exhaust Smell in Cabin and/or DTC P0421 Set due to a miss installed clamp.
Check vehicle applicability
1A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
| Make | Model | Model year |
|---|---|---|
| GMC | TERRAIN | 2018 |
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.