Hello all and thanks in advance for any help!
I have a 2010 Ford Fusion Hybrid with 150k miles and all scheduled maintenance performed on-time. I have a Stop Safely Now light that started intermittently a little over a month ago and is now hard failed.
The first time it happened was 5 weeks ago and I had just returned from a trip out of the country and the vehicle sat 10 days without running. After starting the car I was able to drive about 20 feet at which time I stopped to connect bluetooth and the SSN message illuminated. My first thought was dead or dying battery since I have heard this could cause SSN. I jumped the car and drove without issue for the next two weeks.
Then three weeks ago I got in the car after leaving it parked overnight and drove for about 10 feet before I got SSN. This time I decided to bite the bullet and buy a new 12V battery without testing the installed battery. After installing the new battery I still had the SSN light and I called it a night. Further research shows the 12V battery I removed assuming it was dead was only installed 3 years ago and is likely in serviceable condition.
After letting the car sit overnight with the new 12V battery installed I started it in the morning with no problem and did the fuel trim learning game. I drove with the new battery for 3 weeks with no issues until last weekend.
Now the car has the Stop Safely Now light illuminated on key turn and it will not move under its own power. I used my OBD2 reader to download codes twice.
The first set of codes was downloaded right after the battery change so I am assuming some of the codes are from that:
C1600 - reverse input circuit
C1015 - exhaust gas recirculation sensor B circuit high
U3003 - battery voltage
I cleared these codes after the battery change and I had no engine lights or driving issues until last weekend. I also checked the engineering fault code page on the dash after the battery change and I had no current or historic faults recorded.
Now the car has a OBD2 code C1018 - regen braking and on the engineering fault code page it lists DTC C46200 as a historical fault. Keep in mind I am using a very basic OBD2 reader so it is likely missing some faults.
I have been reading everywhere about the Stop Safely Now issue and it seems to stem from a number of different issues, the most frequent being a coolant pump. I could really use any advice in troubleshooting this issue myself (I am an aircraft mechanic) or relevant manual references. I am trying to avoid a costly stealership repair but I am pretty stuck at this point.
Worth mentioning all of the fuses are in good shape!
Please let me know if you have any questions that would help point in the right direction.