When the service light on your 2005 Escape Hybrid it could indicate at least two possible problems. The first is that there’s an overall problem with the sensor and the second there is an issue with the emission system.
The problems that can be indicated include normal failures such as the module itself or a sensor. Or they could also indicate that there is a problem with the emission system. Emission system problems can range from a canister in the system to a fan or a pump. The emissions system. To determine where the general area might be you will have to run a OBD-II scan and then get a readout with a reader.
Generally, you will need a manufacturer’s OBD-II-specific reader to obtain a finely threaded view of the problem. If you have one of the many OBD-II scanners available, but not one from the manufacturer, then the results will be very generic, such as telling you the five or six major Emissions System warning available in the public domain. Indeed, if you intend keeping your car for a long while, then it might be a good idea to purchase the manufacturer’s OBD-II scanner and a subscription to updates to keep it current.
Most of the time the emissions system will work away flawlessly, until it doesn’t. It is at this time that the OBD-II scanner from the manufacturer will be needed.
Sometimes, though, the Emissions System software is fine. Instead, it is one part of the system or another. It is possible that you will find the answer by running a scan, however, if it is a problem with a short or an open, it may mean you will have to walk stage-by-stage through the system until you find where the issue is. For instance, it could mean there is a short in a loom or wire or it could also mean there is a switch problem. In this case, the OBD-II scanner may or may not find the spot of the problem. However, it might also point to the general area of the issue so the size of the job is more limited.