GEN 2 Limp mode fix?

[USCxGAMECOCK]

Hello guys!

So once again, i'm having issues with my 2017 GEN2. I turn the truck on yesterday only to be greeted by multiple faults at once:

-ABS fault
-Forward Collision Warning fault
-Park Aid fault
-Restraint Indicator Lamp fault
-Steering Assist fault
-Powertrain Malfunction/Reduced Power fault
-U0401 Invalid Data Received(ECM)

Then I realized, after leaving my driveway, that for whatever reason, the throttle was not responding... At all. After doing some research it seems that happens when the truck goes into "limp mode"(Correct me if i'm wrong on that). I have a Pedal Commander so my first thought was that was the issue with the throttle(Before I knew about "limp mode") so I disconnected that and to my dismay, no change. I ended up having to have the truck towed from the bottom of my neighborhood back to my house. I've obviously turned the truck on and off multiple times but no change. I tried resetting the faults on the ECU via a bluetooth OBDII scanner, but no change. The only thing I haven't tried yet was disconnecting the battery to see if maybe that would reset some things.

In my limited research, it seems like a lot of times that when people experience this it just goes away when the turn the truck off and back on. This issue has me very very nervous and anxious because A: this is about the 4th time it's needed to go to the shop and i've only owned it two months(I bought it used) B: this feels so much more major than just a check engine light due to it being unable to drive. C: I'm having to figure out logistics on how to get this thing to the shop, get to work, how long it will be there, etc.

My hope and prayer is that some of you might have experienced this before and might be able to give me some tips or tricks on how to at least get it out of limp mode(I don't know if it can be out of limp mode and still have all of the faults). Any ideas? Feel free to leave me false hope comments so I feel better about this situation because I feel pretty sick to my stomach that I might have a lemon on my hands here.

 

[Clockton]

My Gen 2 has gone into limp mode, you have to take it to a dealer and have them flash the system. The process takes 30 mins and the truck is back to normal. There is a code somewhere that tells you what caused limp mode to kick in.

 

[zombiekiller]

not true that you have to take it to the dealer.

SOMETIMES when you change altitude or gasoline quality ( go to lower octane) , your MAF will get confused as to throttle position when using SOMETHING to manipulate the sensitivity.

Disconnect the negative battery terminal and set the headlight switch to " ON". Move the leys as far away from the truck as possible ( generally outside of the door lock sensors).

Wait 30 mins.

Reconnect battery and start truck.

This is equivalent to a reset.

you can also use a Cobb accessport or a Foxwell OBDII unit to do the same thing without waiting 30 mins.

Hell, you can cause a freaking TCM/BcM/PCM vin mismatch error on the computer by simply changing the tire size in the computer.

These trucks are EXTREMELY sensitive to ANY computer changes.

 

[zombiekiller]

not true that you have to take it to the dealer.

SOMETIMES when you change altitude or gasoline quality ( go to lower octane) , your MAF will get confused as to throttle position when using SOMETHING to manipulate the sensitivity.

Disconnect the negative battery terminal and set the headlight switch to " ON". Move the leys as far away from the truck as possible ( generally outside of the door lock sensors).

Wait 30 mins.

Reconnect battery and start truck.

This is equivalent to a reset.

you can also use a Cobb accessport or a Foxwell OBDII unit to do the same thing without waiting 30 mins.

Hell, you can cause a freaking TCM/BcM/PCM vin mismatch error on the computer by simply changing the tire size in the computer.

These trucks are EXTREMELY sensitive to ANY computer changes.

you may also want to reset the memory/learn function. The whole battery trick should also do that, but with an access port you need to do this manually.

And Pro-tip, if you take the truck to a dealer, take both keys, if they decide to load an updated ROM, they cant do it without both keys.

 

[Clockton]

You may not be in limp mode. Limp mode will allow the truck to still move at around 20mph.

If it is in limp mode then a dealer needs to reset. Confirmed by Ford San Diego, Shaffer’s and others. You can do a reset in the desert on the Gen1s, Gen2 you cannot. I have had this issue. My truck thought it was in a collision, which did not happen, that took a dealer flash to fix it. There is a code that will tell you what triggered the limp if thats what's going on. Post the DTCs in the Forscan thread.

 

[zombiekiller]

you may also want to reset the memory/learn function. The whole battery trick should also do that, but with an access port you need to do this manually.

You may not be in limp mode. Limp mode will allow the truck to still move at around 20mph.

If it is in limp mode then a dealer needs to reset. Confirmed by Ford San Diego, Shaffer’s and others. You can do a reset in the desert on the Gen1s, Gen2 you cannot. I have had this issue. My truck thought it was in a collision, which did not happen, that took a dealer flash to fix it. There is a code that will tell you what triggered the limp if thats what's going on. Post the DTCs in the Forscan thread.

i promise you that you can get the gen2s out of limp mode. ( usually indicated by wrench lights ). I had the same convo with mike shaffer and with jeremiah from exo. I still owe jeremiah the foxwell part number of the little computer tool that will do it.

I learned how to do it when i was having my fueling issue ( which presented as a motor that jumped timing).

i've said it before and i'll say it again... being "first" is rarely as cool , or as fun as people think it is.

The main trick is that you have to reset the adaptive learning when you do the pcm/bcm/tcm reset with the tool. If you do not reset the adaptive learning, the truck slides back into limp within a few seconds.

 

[Clockton]

i promise you that you can get the gen2s out of limp mode. ( usually indicated by wrench lights ). I had the same convo with mike shaffer and with jeremiah from exo. I still owe jeremiah the foxwell part number of the little computer tool that will do it.

I learned how to do it when i was having my fueling issue ( which presented as a motor that jumped timing).

i've said it before and i'll say it again... being "first" is rarely as cool , or as fun as people think it is.

The main trick is that you have to reset the adaptive learning when you do the pcm/bcm/tcm reset with the tool. If you do not reset the adaptive learning, the truck slides back into limp within a few seconds.

Let me know that part number! Its not just a simple PCM relearn and then a TCM relearn is it?

 

[zombiekiller]

Let me know that part number! Its not just a simple PCM relearn and then a TCM relearn is it?

Nah it isn't quite that simple. But it you dont flag for a relearn when you reset the ecu, the first library of DTCs/sensor flags that the BCM looks for to illuminate warning lights and set mode is the persistent adaptive learning messages, which shouldnt immediately trigger limp mode ( at least from my logical perspective), but they do.

I think I probably went through the reset process 10 times before i figured it out.

there are also supercapacitors on the PCM/TCM/BCM boards that need to be discharged so they can no longer make the stored codes persistent, thus why flipping the headlight switch to on while the battery is disconnected is important.

Having the key near the truck will still energize said stored memory banks and the keep alive memory wont die for HOURS if the keys arent away from the vehicle.

 

[USCxGAMECOCK]

not true that you have to take it to the dealer.

SOMETIMES when you change altitude or gasoline quality ( go to lower octane) , your MAF will get confused as to throttle position when using SOMETHING to manipulate the sensitivity.

Disconnect the negative battery terminal and set the headlight switch to " ON". Move the leys as far away from the truck as possible ( generally outside of the door lock sensors).

Wait 30 mins.

Reconnect battery and start truck.

This is equivalent to a reset.

you can also use a Cobb accessport or a Foxwell OBDII unit to do the same thing without waiting 30 mins.

Hell, you can cause a freaking TCM/BcM/PCM vin mismatch error on the computer by simply changing the tire size in the computer.

These trucks are EXTREMELY sensitive to ANY computer changes.

I'm starting this process right now. If this works, how comfortable do you believe I should be to drive the truck?

Thank you so much for this by the way, whether it works or not, I appreciate the help here!

 

[zombiekiller]

I'm starting this process right now. If this works, how comfortable do you believe I should be to drive the truck?

Thank you so much for this by the way, whether it works or not, I appreciate the help here!

If everything clears and it starts up clean, it means that it was a sensor malfunction and the readings have normalized. You should be just fine to drive the truck. Do yourself a favor though and keep the pedal commander off for 50 or so miles.

If it doesnt clear everything, it means something is still catching a reading that is no bueno. If that is the case, I'd have the truck towed to your dealer.