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
CADILLAC, CHEVROLET, GMC
Reported code forms P257D
This engineering information (EI) is requesting information from technicians to perform the check list provided and contact the engineer listed in regards the hood will not latch, open and/or gets stuck, hood ajar…
CHEVROLET
Reported code forms P257D
This Preliminary information communicates that the coolant temperature sensor may leak coolant and wick into the ECM connector possibly causing a Hood Ajar message, CEL and a P257D.
Check vehicle applicability
17A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
| Make | Model | Model year |
|---|---|---|
| Cadillac | ESCALADE IQ | 2025 |
| Chevrolet | IMPALA | 2020 |
| Chevrolet | IMPALA | 2019 |
| Chevrolet | IMPALA | 2018 |
| Chevrolet | IMPALA | 2017 |
| Chevrolet | IMPALA | 2016 |
| Chevrolet | IMPALA | 2015 |
| Chevrolet | IMPALA | 2014 |
| Chevrolet | SILVERADO EV | 2025 |
| Chevrolet | SILVERADO EV | 2024 |
| GMC | HUMMER EV PICKUP | 2025 |
| GMC | HUMMER EV PICKUP | 2024 |
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.