FORScan forum

I recently changed tire sizes on my 2017 F150. My truck is used, have no way to check with former owner if it has a tune. It does have a CAI & borla exhaust, so it is possible. If I change the tire size in Forscan it causes the wrench light to come on, to reset that I'm supposed to reset PCM but a warning pops up saying not to do it if tuned.

I'm curious why you shouldn't reset PCM if tuned? What would the consequences be? And if possible, is there a way to determine if my truck is tuned?

I would assume (knowing other tuned vehicles) that it might screw up your ability to return to stock using the prior owners tuning tool/computer. It's pretty safe bet that the P/O returned your truck to stock and sold the tuner for extra cash prior to turning it in or selling. And that's IF there was a tune installed.

Just pull the negative battery cable for a few mins, should clear the code, else bite the bullet and do a PCM reset.

UPDATE: PROBLEM SOLVED. I'M LEAVING MY ORIGINAL POST FOR THOSE SEARCHING THE SAME ISSUE. I SOLVED IT BY UPDATING TO FORSCAN VERSION 2.322. IT NOW INCLUDES A "TCM RELEARN" OPTION. I HAD TO RUN BOTH THE PCM RELEARN AND THE TCM RELEARN TO GET THE DTC TO GO AWAY.

ORIGINAL POST:
Please help. I can't get rid of the wrench after changing BCM 726-12-01 to 09E7 (was 09AC). Speedo is right on the money though. I have researched all the forums, run the Module Initialization/Relearn function several times, tried to delete the TCM DTC P160A multiple times. No other DTCs exist. This is a very persistent wrench.

Vehicle info: 2018 F150 Lariat, 3.5L Ecoboost Screw, FX4, 3.55 diff, new LT275/70R18 Michelin Defender LTX M/S tires.

I changed the circumference on my 2018 F150 and the wrench light came on but I changed a few other things at at the same time. I wil try the relearn on mine tomorrow and post back if it solves mine. Glad I found this thread
Thanks

sragsdill wrote: Thu May 16, 2019 10:15 pm UPDATE: PROBLEM SOLVED. I'M LEAVING MY ORIGINAL POST FOR THOSE SEARCHING THE SAME ISSUE. I SOLVED IT BY UPDATING TO FORSCAN VERSION 2.322. IT NOW INCLUDES A "TCM RELEARN" OPTION. I HAD TO RUN BOTH THE PCM RELEARN AND THE TCM RELEARN TO GET THE DTC TO GO AWAY.

Couple questions:
Did you discover if you had a tune or not?
IF you had a tune, was the relearn function without issue?

I have had a tune as an ecu remap and am very cautious of the warning that suggests reflashing back to stock before changing values and then reapplying the tune. My tune guy is remarkably unhelpful with this unfortunately

I think resetting the PCM does indeed do something. I had 2 dealership PCM firmware updates and every time after, the engine`s output power seemed a bit below what i had been used to. So, doing a "PCM reset" after these firmware updates, brought it back to my liking. The down side is, consumption seems to have increased a little.