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 wording
Source wording can vary by vehicle and suffix. It is shown as written, not as a universal diagnosis.
P2CEF00Electrical fault or open circuit in coolant thermostatManufacturer communications
3Original wording in English
LOTUS
Reported code forms P2CEF00
Emira 4-Cylinder vehicles only - Issue 3 includes updated information on thermostat the testing method and replaces version 2 of this bulletin published on 05.08.2026. Diagnosing medium temperature engine coolant…
LOTUS
Reported code forms P2CEF00
Diagnosing medium temperature engine coolant thermostat operation to prevent unnecessary thermostat replacement. The information in this bulletin is intended as a procedure that should be performed if a 4-cylinder Emira…
MERCEDES-BENZ
Reported code forms P2CEF00
Complaint Customer states that the CEL is lit in the instrument cluster. Various codes may be active/stored: Stored in N3/10 in model series 206, 254 or 232: P012800 - The coolant temperature is below the coolant…
Check vehicle applicability
16A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
| Make | Model | Model year |
|---|---|---|
| Lotus | EMIRA | 2027 |
| Lotus | EMIRA | 2026 |
| Lotus | EMIRA | 2025 |
| Lotus | EMIRA | 2024 |
| Lotus | EMIRA | 2023 |
| Mercedes-Benz | AMG C43 | 2024 |
| Mercedes-Benz | AMG C43 | 2023 |
| Mercedes-Benz | AMG C43 4MATIC | 2023 |
| Mercedes-Benz | AMG CLA45 | 2024 |
| Mercedes-Benz | AMG CLA45 | 2023 |
| Mercedes-Benz | AMG CLA45 | 2022 |
| Mercedes-Benz | AMG CLA45 | 2021 |
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.