Replaceing Rear Diff Module

I was thinking you weren't supposed to change the rear drive unit (RDU) out without changing the module because the modules are calibrated to the RDU they were delivered with. I think if you replace the module you have to be able to pull the settings from your old module and then push them into the new unit, I believe they call it an inhale-exhale process. If your old module is not working enough to get the settings and if there's no other ways of getting the settings for that rear drive unit, from some tag on it or something that can be manually loaded to a module I think you have to replace the RDU and module as an assembly again. Again there may be some way that they can see what calibration needs to be loaded to the rear module if they do just the RDU system.

What I do know you can't just swap the rear driving without doing some calibration changes on the rear module (perhaps getting the module with the rear unit if you can't load calibrations without doing an inhale-exhale) so if that wasn't done the rear module may be very confused by the reactions it's getting from the RDU to the inputs it's giving it because it's potentially out of specs from what the loaded calibration of the module is.

Did you read the pictures of the service manual that were posted in that thread?

PAWEL RS2017 said:

... So if you just swap a old unit for new, connect plugs the system will not work? How the hell it's calibrated....

Click to expand...

No, it will not work correctly if you just swap the parts. It's calibrated according to the factory service manual by using the IDS tool connected to the car to push the configuration into the all-wheel drive module. If you read that you can do it without doing the inhale-exhale from the old control module to the new module, it also states that if you are replacing the module without a control unit you must push the calibration in. The calibration can be found stamped into the RDU. I don't think it's stupid for the amount of precision they need to get into for the proper control of the vehicle. General assembly variations between clutch pack thickness or spring tension or flow rates for hydraulic system can have variations so having tested and calibrated on their systems to build a profile of that specific piece of hardware then you tell the computer what that specific piece of hardware's profile is so it knows how to control it properly to get the expected outputs.

If that is hard to read.... Blame voice to text.

But what you can do and what a dealer is allowed to do when they are a Ford dealer or two different things. The BCMs are not the same between Europe and US. It was other differences The sensors for all the automatic headlight wipers as well you asked the 16 model had the area to support some of that but none of it was ever put in the car. We never had the city emergency braking feature. I mean the reason you could be simply that they don't want to support a car from outside the market area simply prevent people from feeling like they should be allowed to import them and use them as easily there because they make it difficult you're less likely to want to do it that may be all the reason they need I mean they're a business. Perhaps in some markets they have an issue with black market cars that were stolen in the US making it to those areas and they decided we're not going to support any US market cars in our area because odds are it might be a stolen car from the US. Again I don't know their reasoning but mean it is their business and they can pretty much choose not to work on something that's out of market area without having to give much reason other than it wasn't sold here it doesn't meet the configuration of the cars we were supposed to work on based on our training for Ford we're not doing it.

By choosing to buy an out of market car you choose to take it on yourself to do all the work automatically in my mind. If I bought an imported car from Honda that I can legally import the US now I'm not going to take it to the Honda dealer and tell them oh you have to work on this because it's a Honda. While the car may be very similar, there may be small variations unless they pay extra close attention to that they could mess up something worse on the car that they may be responsible to fix then.