Engine Light

[Bounder47]

I own a 2017 Fleetwood Bounder 33c, with a V10 motor on an F53 chassis. My engine light has come on and will sometimes blink. I took it to a friends auto repair shop. He owns a motorhome also. He ran a diagnostic check. It showed that 5 pistons misfiring, but when test driving my coach it runs perfect. He said that it would be very noticeable if the pistons were misfiring. He believes that it is a mapping error in the computer and that there is nothing wrong with my coach. My coach is under warranty, so I took it to my local Ford Commercial shop. They found the same issue and were able to reset my computer, but after 3 months the light turned back on and my rig still runs perfect. I returned to Ford and they could not reset the engine light and said that the coach is not misfiring as the computer shows.
Has anyone had this issue?

[TandW]

Bad plug wires set codes as compression rates go up during hill climbing or heavy acceleration. High compression makes it harder to produce a spark at the plug when the wires are failing.

[77Travco]

I also have a 2017 Bounder 33C. I'm at 27k miles with no issues.
How many miles are on your coach? What codes are showing up? It makes no sense that Ford would not be able to reset codes unless they are immediately coming back.
Move those 5 coils to other cylinders and see if the issue follows the coils.
After that, inspect the condition of the plugs. Look for any signs of a lean condition on those 5 cylinders.
Swap in a new set of correct Motorcraft plugs while your in there. Inspect those boots and change them if needed.
I have a ScanGauge2 that plugs into the OBD2 port near the left side of the steering column. It gives me all kinds of info, especially about the engine. Very common item, I bought it at my local auto parts store.
I personally do not trust others to work on my equipment. Warranties are useful for things like component replacement. I prefer to do all my own work, warranty or not.

[Bounder47]

We also have the same ext. color. I have about 12,000 miles, so low mileage. I bought it new. I'm gonna have my friend start off with the wires and plugs. I had a shop wanting to charge me $3,400 for repairs. My friend who has his own shop, but doesn't particularly work on RV;s said that he understood, their thinking, but strongly feels that it is a mapping error on the computer. I have driven over 1,000 miles with the engine light on with no issues.

[77Travco]

Originally Posted by Bounder47

We also have the same ext. color. I have about 12,000 miles, so low mileage. I bought it new. I'm gonna have my friend start off with the wires and plugs. I had a shop wanting to charge me $3,400 for repairs. My friend who has his own shop, but doesn't particularly work on RV;s said that he understood, their thinking, but strongly feels that it is a mapping error on the computer. I have driven over 1,000 miles with the engine light on with no issues.

Nice!
There are no wires... just Coil On Plug (COP). Each cylinder has a coil and spark plug. I would be curious to see the condition of those plugs. If any of them look like a lean condition then there could be a fuel delivery issue.
I would stay away from any $3400 diagnostic estimate!

[Donkey7679]

A couple of things, which code was thrown for the misfire? The Ford V10 can throw several misfire codes, unfortunately they all can “lead” to different or similar repairs. Oddly a very common misfire code PO171 and 174 show misfire on either “even” “odd” banks of the engine but usually are caused by either a dirty throttle body or the vacuum line leaking that connects to the bottom side of the throttle body. So sometimes a misfire code “isn’t” really a misfire. The engine will run fine but run lean and send that code. You would think the O2S would pick that up?? Yeah, odd! I have been dealing with V10s since 2003, great engine but very quirky at times.

[Bounder47]

Got it, thank you.

[Bounder47]

Yup, thanks.