Possible causes could include:
* Loose or damaged gas cap: This is the most common and often easiest to fix. A loose or faulty gas cap can allow fuel vapors to escape, triggering the light.
* Faulty oxygen sensor(s): These sensors monitor the amount of oxygen in the exhaust and help the engine control unit (ECU) adjust the air-fuel mixture for optimal combustion and emissions. A malfunctioning sensor can lead to poor fuel economy and emissions problems.
* Malfunctioning catalytic converter: This is a more serious and expensive problem. The catalytic converter reduces harmful emissions. A failing converter can lead to significant emission issues.
* Problems with the evaporative emission (EVAP) system: This system prevents fuel vapors from escaping into the atmosphere. Leaks in the system can trigger the warning light.
* Issues with the hybrid system itself: In a hybrid, the emission system is more complex, and a problem within the hybrid components (battery, motor, etc.) could indirectly trigger this warning. This is less likely to be the primary cause but should be considered.
* Other sensor malfunctions: Various other sensors related to engine performance and emissions could be at fault.
What you should do:
1. Check the gas cap: Ensure it's tightly secured. Sometimes, simply tightening the cap will reset the light. Drive for a day or two to see if the light goes off.
2. Get it diagnosed: If the light stays on after checking the gas cap, take your 2005 Ford Escape Hybrid to a qualified mechanic or a Ford dealership. They can use an OBD-II scanner to read the diagnostic trouble codes (DTCs), which will pinpoint the specific problem. Don't attempt to fix it yourself unless you have extensive automotive experience.
3. Don't ignore the warning: Continuing to drive with this light on could worsen the problem, potentially leading to more expensive repairs and potentially damaging the catalytic converter.
Ignoring this warning light can lead to failure to pass emissions testing (if applicable in your area) and potentially damage to your vehicle's engine or emission system. Professional diagnosis is essential.
