How do I bypass the L5P limp mode now that my CAN bus plugs failed and the DPF is gone?

[HardPiston_Lab]

I'm in a total nightmare. I bought a CAN bus plug kit for my L5P delete, but none of the resistors are communicating. The truck is now hard-coded into a permanent limp mode because it 'miled out' and needs a regen. The problem is, I already cut the factory exhaust out, so there's no going back. How am I supposed to reset the regen timer or force the ECU to see these plugs? Am I looking at a bricked ECM, or is there a specific diagnostic tool that can flash past this without the factory sensors present?

 

[TruckerChief]

You need a tuner. The plugs only fix communication; they don't 'delete' anything. You are trying to run factory software with zero backpressure and no sensor feedback, which is why the ECM is freaking out. How are you trying to flash it? If you're using a locked ECM, you might be at a dead end. You need an unlocked ECM (2017+ requirement) and a platform like EZ LYNK or EFI Live to bypass the emissions logic entirely. Do not tow it to a dealer—with the exhaust cut, they’ll flag your VIN and the repair bill will be astronomical.

 

[IronBed]

Are you using an unlocked ECM? Remember, 2017+ L5Ps require the ECM to be physically unlocked before they can accept a delete tune. If you're trying to flash a stock, locked ECM while the sensors are missing, you’ll be stuck in limp mode forever. You need a platform like EZ LYNK or EFI Live with a tune that specifically ignores the EGT/NOx CAN messages. Check with your tuner to see if they can send you a 'Recovery File' to force-flash over the regen lock.