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 P066A
This engineering informational bulletin is requesting information from the field to determine a root cause for a condition of Service Engine Soon (SES) Light On, DTCs P06C5, P06CC, P066A, P066C, P066E, P067A, P067C,…
RAM
Reported code forms P066A
Glow Plug Missing O-ring This bulletin involves the replacement of the glow plugs because of a missing internal O-ring. The customer may describe a Malfunction Indicator Lamp (MIL) illumination and/or a blinking glow…
Check vehicle applicability
6A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
| Make | Model | Model year |
|---|---|---|
| Chevrolet | SILVERADO 2500 | 2019 |
| Chevrolet | SILVERADO 3500 | 2019 |
| GMC | SIERRA 2500 | 2019 |
| GMC | SIERRA 3500 | 2019 |
| Ram | PROMASTER | 2015 |
| Ram | PROMASTER | 2014 |
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.