Cold Start Wrench Light

[t_j]

Every time i have seen a wrench light its been a blocked air filter of some form (snow, dust, ice, water yeah i'm looking at you @mnblly), check your MAF also.

 

[mnblly]

Every time i have seen a wrench light its been a blocked air filter of some form (snow, dust, ice, water yeah i'm looking at you @mnblly), check your MAF also.

it doesn't like mud either

 

[tinman44]

SCT tool. It will start and warm up and then idle down until it stalls. Pressing the accelerator does nothing.

 

[Dirt Bag]

Just saw this post. I had the same thing including really poor cold starting. Like a few seconds of cranking. Took it in and they replaced the fuel pump and everything is better now. It was covered under my extended warranty. I am at 55000 miles.

 

[SVTRay]

Every time i have seen a wrench light its been a blocked air filter of some form (snow, dust, ice, water yeah i'm looking at you @mnblly), check your MAF also.

I wished that was the problem with mine. I checked the air filter and it's clean.
Now my first run in with the wrench light was after drying in snowy conditions but the light persisted despite the weather after that point. I gave it to Ford and they said it was the Mechatronics unit. Ford replaced the Mechatronics Unit and 4 days later my truck is screwed up again...this time it doesn't shift gears completely...only the first 2-3 gears tops.

I'll mention the MAF to Ford tomorrow and see what happens. The idea that this transmission can be effected by something as simple as a dirty air-filter or MAF is idiotic. Not you guys, the designers.

 

[HAP]

Try the battery disconnect for an hour. It free and cant hurt to try...

 

[t_j]

I wished that was the problem with mine. I checked the air filter and it's clean.
Now my first run in with the wrench light was after drying in snowy conditions but the light persisted despite the weather after that point. I gave it to Ford and they said it was the Mechatronics unit. Ford replaced the Mechatronics Unit and 4 days later my truck is screwed up again...this time it doesn't shift gears completely...only the first 2-3 gears tops.

I'll mention the MAF to Ford tomorrow and see what happens. The idea that this transmission can be effected by something as simple as a dirty air-filter or MAF is idiotic. Not you guys, the designers.

Well i think the wrench light means torque miscalculation, but its commonly caused by air flow issues. Maybe your torque converter is failing? @13raptorcrew may be able throw you more ideas for things to check.

 

[SVTRay]

Well i think the wrench light means torque miscalculation, but its commonly caused by air flow issues. Maybe your torque converter is failing? @13raptorcrew may be able throw you more ideas for things to check.

Ya, I replaced the torque converter back when I dealt with that bell house fluid leak issue. Figured it was out, may as well.

Anyhow, it would suck if this was a MAF issue after I spent 2k replacing the Mechatronics Unit.

 

[13raptorcrew]

Correct, a wrench light is likely a torque mis calculation, which (due to the way we use these trucks) is likely caused by dirt/snow/ice/water/bugs on the MAF sensor. If the sensor cannot detect the amount of air entering (due to the aforementioned conditions) the PCM will have a hard time trying to calculate the load.
Transmission shift points take into account engine load.

But based on @SVTRay 's mention of the shifting only the first 3 gears, a transmission concern is possible. The PCM is monitoring many things and has determined that whatever concern is present may result in further harm therefore it may take away functions to reduce the collateral damage.

Sorry for the troubles @SVTRay but hopefully the dealer can find out what is wrong.

 

[SVTRay]

Correct, a wrench light is likely a torque mis calculation, which (due to the way we use these trucks) is likely caused by dirt/snow/ice/water/bugs on the MAF sensor. If the sensor cannot detect the amount of air entering (due to the aforementioned conditions) the PCM will have a hard time trying to calculate the load.
Transmission shift points take into account engine load.

But based on @SVTRay 's mention of the shifting only the first 3 gears, a transmission concern is possible. The PCM is monitoring many things and has determined that whatever concern is present may result in further harm therefore it may take away functions to reduce the collateral damage.

Sorry for the troubles @SVTRay but hopefully the dealer can find out what is wrong.

Interesting stuff, Thanks!

I guess it all makes sense then. The first 2-3 years I used the truck in the West Texas desert. Then the following years has been in East Texas dealing with major floods. It's been stuck in the mud as well...more work related than playing. We just recently bought a vacation home in the Colorado foothills and I have made several trips back and forth with it snowing each time. This issue first manifested after my last Colorado trip. So ya, I can see that MAF being dirty. I regularly change the air filter but never thought about the MAF.

Anyhow, do you think I should replace the MAF at this point since it's 6 yrs old and has 91k on it?