My speedometer was never correct with the smaller tires. When I put the larger tires on it, the speedometer is correct (when compared to GPS).
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How to: Recalibrate Speedometer with Forscan for 2021 Bronco
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Yeppers.
First you change the tire circumference in MM (by 2% in your case) in the BCM. Then you have to relearn the PCM and AWD modules. AWD works great, PCM is where we get the error. And if you leave it, you get a trouble code. The speedo does change, but there is a DTC.
Several people have indicated that they just left it with the code. I’m not sure what other stuff relies on the tire size being committed properly in the PCM, so I always put it all back in my attempts to get it to work.
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That’s awesome and lucky! My tire size adventure has been less satisfying, but based on all the research and poking around I’ve done I came to the conclusion that the speedo must be significantly off for a stock Black Diamond. The BCM is set to 2440mm, which is much smaller than the 265/70R17.
Out of curiousity, what tires did you put on that made the speedo correct without editing?
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P160A Error Solved.
After completing the tire size change in the BCM and writing the new settings you must then execute a RELEARN on the AWD module. Merry Christmas!
After completing the tire size change in the BCM and writing the new settings you must then execute a RELEARN on the AWD module. Merry Christmas!
Does that clear the P160A DCT? I haven't been able to clear it. I have re-learned the AWD module and the PCM module, but the PCM module won't relearn (it fails at 2% with the infamous "service procedure interrupted" error) - which leaves the P160A (at least for me).
Were you able to get it to clear just by relearning the AWD module? Have I been doing it wrong all along? I would be thrilled to find that out.
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We upgraded to the latest FORSCAN (.44) - I cannot for the life of me figure out how to get the PCM MODULE to relearn , but it doesn’t matter as long as you RELEARN THE AWD MODULE - the error goes away and the wrench disappears from the screen.
Yes. Appreciate the update but that’s not what we are all talking about. We are talking about the PCM error. I believe all of us have relearned the AWD to clear the wrench. But it’s the PCM error that’s driving us nuts. Thanks for the input though.
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Okay, got it now - I’ll keep monitoring the thread to see if someone else can figure it out. I would suspect the solution lies with FORSCAN. I am using the OHP SCANNER and they brag that it “works flawlessly with FORSCAN”! Is anyone pursuing this with FORSCAN - it has to be something related to their software…
When I try and do the PCM relearn It won't run, I says the process has been interpreted. I can do the AWD relearn no problem, Any ideas why that might happen?Just make sure after you change the tire size to force the TCM and PCM to relearn and do the reset of the DTC, then you should not have any error messages:
13. Now we have discrepancy between tire size values known by PCM and TCM and new value stored in BdyCM. So we have P160A DTC in TCM module and P0610 in PCM module:
14. In order to remove the discrepancy, we need to force PCM and TCM to “learn” the new value from the ECC. We can do it using Module Initialization/Relearn vehicle data functions for PCM and TCM module:
Note: some cars may have other modules that require this operation, for example AWD, SOBDMC.
15. After running the Relearn functions, we need to reset the DTCs:
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Got it, I was able to take it to my dealer and they were able to run both relearn's using the official Ford tool. So I am good to go, but it's annoying not to be able to do it at home.
Wow. You may have solved everyone’s trouble. Provided the dealer knows what they are doing. And will do it.No, I'm all good, these are the values I set mine to. No lights, no error codes.
So this is the exact series of events we followed. Changed the circumference in Forscan myself, then went to do the AWD relearn, which went fine. Then I tried the PCM relearn in ForScan, no luck. Took it to my dealer Spirit Ford in Dundee Michigan. They hooked it up in FDRS right in front of me ran the simple PCM relearn took 2 minutes, then we cleared the codes. No lights no issues, circumference is still where I originally set it. Been driving on it for 2 days with no issues.
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