I have a 2007 Ford Fusion 4.0L AWD. One day I went to pass a slower car and accelerated rapidly, but the car responded with loss of power and shook to a stop and would not re fire. I took it to the dealership and they said two cylinders were not firing and a fuse was blown. I looked on the internet and some people said their coils go bad or plug wires. I asked the dealership if that was the cause and they said absolutely not, but it’s the ECM. They replaced the ECM and 2 days later my CEL came on and I took it back to the dealership and they told me my catalytic converter was bad and I could drive it until I had the money to replace it. Then a couple days go by and I was passing a tractor on the highway, I slowed down to 45 mph to make the pass and as I began to accelerated I felt a thunk, then about a mile later it started cutting out and shaking. This time it would re fire but idle rough. I tried on/off 3 or 4 times then it idled o.k. I then took it back to the dealership and this time they said it’s all 6 coils. Any thoughts? thanks
Coils are often killed by aged spark plugs and sometimes by moisture in the plug wells.
Have the spark plugs ever been changed and how many miles on the vehicle? I ask because Ford, as do some others, recommend 100k miles or more plug changes and this is a bad recommendation in my opinion.
The info I looked at shows power from fuse 48 supplies power to all of the coils which are turned on through the PCM. There is also a capacitor tied to ground on the power lead; most likely used for noise suppression. It is very strange to me that all of the coils seem to be bad now and I wonder if that is really the case. I assume that the fuse that was replaced was fuse 48 for the coils. I have to wonder if the original trouble to the ECU was caused by the two coils that weren’t working correctly or if the trouble was really caused by faulty plugs tied to the coils. My suspicion is that old plugs are causing the real problem. Like @OK4450 stated. At this point replacing the coils, wires and plugs may need to be done in order to eliminate the issues. I would also replace the capacitor and make sure it is grounded well as it may be the cause of the original trouble.
A plugged cat converter could indeed cause this symptom. So could a dirty air or fuel filter or fuel pump on the fritz.
Wouldn’t a catalytic converter be covered by warranty on a 2007?
I think the warranty period also depends on the state. I’ve heard – this may or may not be true – that Calif requires new car smog eqpt be warranted for 100K miles independent of the amount of time.
I think it’s time to try another dealer. It sounds like they’re grasping at straws, and I can’t imagine a scenario where all 6 coils could go bad unless the car was hit by lightning or was near a nuclear explosion that created an electromagnetic pulse.
Agree with OK4450. Just had this same scenario with a 2003 Taurus. Understand that this is not just with Fords.