Wheel speed sensors control transmission shift points?
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Wheel speed sensors control transmission shift points?
2013 Q7 tdi.
Question is if the tcu uses the wheel speed sensors to control the transmission, i.e. shift points, etc? Or does it rely only on the trans input/output speed sensors?
Question is if the tcu uses the wheel speed sensors to control the transmission, i.e. shift points, etc? Or does it rely only on the trans input/output speed sensors?
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Traditionally, wheel speed sensors tie into ABS system and stability control. On this car, they also tie into the quattro system, as well, which has a locking center diff, but none at the axles...those are managed electronically via the ABS system. Transmissions normally just use the output/input speed sensors, but there is likely going to be some extra wizardry taken into account by the TCU, such as windshear, or the speed of a coconut laden swallow, for example.
Also, the shift points 'logic' is predetermined based on the shift 'map' software version installed in the TCU. If you have VCDS, then you can modify the shift map from the Audi Q7 'dieselgate' / downgraded version currently loaded, which sucks and forces early shifts, and switch to a different map. The Porsche Cayenne map is quite popular with the Gen 2 TDI crowd; I have it loaded on the '15, but I'm going to try the T-Reg map also, and see how it feels. On the '10 w/6spd, I selected the OE, pre-dieselgate, Audi map, and it's been very perky since then. You also do a throttle reset/relearn adaptation. It's a fly-by-wire throttle pedal, BTW.
Also, the shift points 'logic' is predetermined based on the shift 'map' software version installed in the TCU. If you have VCDS, then you can modify the shift map from the Audi Q7 'dieselgate' / downgraded version currently loaded, which sucks and forces early shifts, and switch to a different map. The Porsche Cayenne map is quite popular with the Gen 2 TDI crowd; I have it loaded on the '15, but I'm going to try the T-Reg map also, and see how it feels. On the '10 w/6spd, I selected the OE, pre-dieselgate, Audi map, and it's been very perky since then. You also do a throttle reset/relearn adaptation. It's a fly-by-wire throttle pedal, BTW.
Last edited by '10Q7TDI_Prestige'; Mar 18, 2022 at 05:08 PM.
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Thank you, your understanding matches mine, I just hope the wizardry is kept at a minimum.
Fyi, I'm attempting to swap the cnrb engine/trans into a Jeep Wrangler, so I've got a lot of things that could go wrong... just trying to stay ahead of them.
Fyi, I'm attempting to swap the cnrb engine/trans into a Jeep Wrangler, so I've got a lot of things that could go wrong... just trying to stay ahead of them.
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Ya know Jeep/Chrysler makes diesel engines already compatible with that chassis, right? I would definitely be seeking out guidance from a pro/specialty shop prior to turning any wrenches in that transplant direction...talk about risky business; Audi's control systems don't exactly play nice with others, lol. Seems like an awfully big can of worms to open up for a project Jeep, especially if you don't own a custom fabrication/automotive shop. I do not claim to be well-versed on the intricacies of brain surgery, such as your project will require. Go find someone who's already done it successfully, or don't do it; that's my advice.
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From what I can find online, I'm the first. 😁
I've spent the last year planning this on paper, looking for donor vehicles. I found both recently. I'll be doing a test fit in the next week or so. I am keeping the jeep transfer case and fabbing a custom adapter and I'll be working closely with Malone with their custom tunes.
Let the fun begin!
I've spent the last year planning this on paper, looking for donor vehicles. I found both recently. I'll be doing a test fit in the next week or so. I am keeping the jeep transfer case and fabbing a custom adapter and I'll be working closely with Malone with their custom tunes.
Let the fun begin!
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