Speed sensor

Hello,

The Direct Trouble Code[DTC] C1123 is indeed a DTC for the Luggage Compartment Lid as CarMax stated. DTC B1676 is a DTC concerning your vehicle's AntiLock Brake Control Module. I have included a diagnostic troubleshooting guide for DTC B1676 from the vehicle manufacturer, as well as ABS Control Module wiring diagrams, a guide on how to find an open in an automotive electrical circuit, as well as how to measure unwanted resistance in an automotive electrical circuit using the voltage drop method in the diagrams down below. You will need to use a Digital Multi-meter [DMM] to go through these guides, so here is a link below to a guide explaining how to a DMM below:

https://www.2carpros.com/articles/how-to-use-a-voltmeter

Please go through these guides and report back with what you find.

Thanks,
Alex
2CarPros

Just to jump in, a flashing check engine light indicates a severe misfire. I am surprised they did not pick up any codes but Ford can be pretty bad about that. Sometimes it will post the misfire code and sometimes it will not.

With an advance scan tool they can go into a different menu and look at mode 6 data and read the misfire data. See image below. A2 would be cylinder 1 and so forth. The cylinder with the highest misfires I would swap that coil with a cylinder with close to no misfires, reset the computer and road test under same condition. If misfire follows where you moved it for example A2 cylinder one and A4 cylinder three then the coil is faulty. If no change then move around the spark plugs and fuel injectors.

Those are just examples but you need someone that really knows how to read and interpret that data and that is more of an advance level specialist to get in there. Those are my thoughts with the flashing check engine light.