Hi,
I have a 2009 FX4 with about 118k miles on it and have some intermittent issues over the past year or so which seem to be getting worse. I was hoping to get help formulating a plan of attack to try and slay the gremlins from my truck. I am taking the car to the dealer for investigation but it is hard working thru the service adviser on these type a issues and I think it would be helpful to get some opinions/ideas prior to going that route.

Here is a brief summary of the issues:

Issues typically only happen on longer trips
check engine light, many times
wrench light, limp home - just on recent trip
traction control light stuck on some times
emergency flashers turn on by themselves, just once after car turned off recently
display glitching / flashing, couple times on recent trip
tranny stuck in third gear until power cycled and trying to change gears with shifter would not work but it would go into reverse and netural. Happened twice on recent trip
very chuncky noise when driving a few times, tranny? ABS?
Codes pulled:
U0100 - lost comm w/ ECM/PCM
P260F - Evap system monitor processor
P115E - throttle accuator control throttle body air flow max
U0073 - control module comm bus A off
U0102 - lost comm w/ transfer case
U0121- lost comm w/ anti lock breaks
U0155 - lost comm w/ instrument panel
U0154 - lost comm w/ restraint control
U0253 - lost comm w/ accesory protocol interface module
U0151 - lost comm with restrain control module
U0101 - lost comm w/ transmission control module

only mods I have are a viper alarm and a lockpick to add a backup cam to the factory nav system.

Thanks!

 

If my truck had a laundry list anything even remotely like yours, it would be on its way to the dealer with me coming home in a new truck. This could get expensive and quick to fix. The 2017's should be discounted pretty heavy since the new ones are about on the street and with a new body style.

 

Just a thought.....when was the last time you did a serious load test on the battery?? The common threat in many of those complaints seems to be electrical.......maybe check to be sure the connections are nice and clean and the ground is good as well. Might be as simple as a bad cell in the battery causing a voltage issue.

God luck with it.

BJ

 

Labnerd - yep a new truck would be nice but the wife is in line for a new one first so.....

Razorsharp1 - Thanks for the suggestion, I did recently clean the terminals and tighten up the bolts, no issues observed since but no longer trips also.

Got an appointment this Friday but not expecting and great revelations. My gut feeling is just some intermittent shorts/opens in a cable harness which will be next to impossible to trace.

 

Any major warranty or collision work done?

Water leaks? Or symptoms related to rain/car washes?

 

Hi Patman, Thanks for the comments/questions. So no accidents or major work on the engine, just oil changes, spark plugs, and new serpentine belt. I did find the guys who changed my oil last time left the air filter housing clips unhooked which might explain the P115E - throttle accum control throttle body air flow max.

I cleaned the mass airflow sensor and I also pulled and re-seated any fuse or relay associated with the PCM.

I did have a water/mud incident about a year ago when stuck in a Baja downpour. So much mud on my truck they pulled me into secondary at the border.

The truck has had a fair amount of off road pounding and actually a couple times that is when the CEL happened. That is why I'm suspecting wiring/connector issue possibly.

Probably pretty expensive to replace PCM harnesses I'm guessing!

Thanks

 

Lost communication is typically voltage/ground issues.

Generally speaking harnesses are pretty robust, but the modules can't talk without proper power/ground to boot up

 

Patman, thanks again for the comments.

Took the truck to the dealer this a.m. - the advisor looked at the code list I provided and said......bad battery but lets see what the tech finds.

Got a call and he said the battery was OK but the throttle body was very dirty and that was my main problem. Not sure that explains computer communication problems but he also said the PCM needed re-calibration.

I wonder if the shop that left my air filter housing unclipped will pay for the throttle body cleaning?

 

Well as expected I got more/same codes showing up after the dealer visit

1) U0073, control module comm bus A off
2) U0100, lost comm w/ ECM/PCM
3) U0151, lost comm with restrain control module

I'm still thinking some wiring issues

 

Well I took the truck back to the dealer after the limp home wrench showed up on the dash and I got the 3 communication code listed above.

Their classic response that they actually put in writing " These are communication codes and should be ignored. No concern is present with the vehicle at this time"

I think I'll gonna fill out the visit survey this time, how could lost communication with the restrain control module not be considered a safety issue?

 

can't believe the tech doesnt want to attempt it....

 

So now one day after they said "ignore the error codes" the truck once again went into Wrench warning light limp home mode. The truck was stuck in third gear again and I drove it straight to the dealer in this mess up mode. Asked to talk to the tech supervisor and he looked at the previous days write up while he pulled many many codes. He was a bit baffled by the previous tech comments but did not have any real good ideas. He said that until all aftermarket electrical mods are removed that ford really can't go any further. I have a coastal lockpick backup cam module that interfaces the NAV Radio and a viper 5901 remote start alarm. I pulled the lockpick and so far no fault lights on the dash. My fingers are crossed that it was the lockpick as I really don't want to pull the viper alarm.

 

Well I pulled out the lockpick and the remote start and.......truck is still messing up. Going back to dealer but I'm $600 into this fun so far and this will be the 4th trip to the dealer.

Today the instrument panel started freaking out, gauges and display all over the place. I think I saw a couple post about bad Instrument cluster causing these communication errors. Might have to shotgun a new display to see if that is it.

 

Inspect the harness at the transmission connector and along the length of the transmission

 

Connector looks pretty nasty from the original leak I think which was replaced years ago.

Here is a link to a pic of the connector and a vid of my cluster going nuts.

https://photos.google.com/album/AF1Q...M33W0yFnlF1HRY