Viper tuned TCU

4.2 V8 40v biturbo - 450 bhp
4.2 V8 40v biturbo - 480 bhp (plus)
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Gav66
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Viper tuned TCU

Post by Gav66 » Sun Mar 10, 2019 12:55 pm

Had this problem for a while now after a full service had a chat with Shopp about it and we thought it best to run the car for a while and see what happens. Basically car went in for service and came back out with the gear box feeling as if it went back to standard from the viper tune it had. So after a while I phoned unit 20 where it had been looked after for a while and after explaining to the gentleman what had happened he suggested checking a green wire that goes to the TCU as it could have corroded thru time. I have lifted the carpet in drivers footwell and was hoping to see a seperate green wire but nothing.
Photo attached of the TCU, any ideas anyone.
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20190310_114033.jpg
Vipertuning 30mph

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Gav66
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Re: Viper tuned TCU

Post by Gav66 » Sun Mar 10, 2019 2:15 pm

I opened up the TCU and everything looks ok, nothing corroded or loose, carpets all dry. Mind you I haven't a clue what I am looking for.

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Re: Viper tuned TCU

Post by Shoppinit » Sun Mar 10, 2019 2:25 pm

What's it doing / not doing? I can't remember.

/don't see any pure green wires going into the TCU. Plenty of green with other colours.
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."

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Re: Viper tuned TCU

Post by Gav66 » Sun Mar 10, 2019 2:37 pm

Hi Shopp, it's never reverted back to what it was, 30mph in fifth also it's not been changing gears like it used to do.

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Re: Viper tuned TCU

Post by Gav66 » Sun Mar 10, 2019 2:39 pm

It now has what I can only explain as a kind of lull before changing gear where as before it was instant

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Shoppinit
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Re: Viper tuned TCU

Post by Shoppinit » Sun Mar 10, 2019 2:41 pm

Who did the service? Audi? Maybe they flashed the TCU during the service. Doesn’t sound likely unless there’s been a service campaign to update tcu software discreetly. Doesn’t seem likely either.

Was the gearbox serviced?
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."

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Gav66
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Re: Viper tuned TCU

Post by Gav66 » Sun Mar 10, 2019 2:50 pm

It was local Audi specialist, he didn't fit the air box properly and all the lights on the dash were on, had a chat with yourself and reseated the box properly under your instruction also a vacuum pipe had come of going to a DV I think. Box has been serviced 4 weeks ago at another reputable Audi specialist who was an Audi tech.

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Shoppinit
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Re: Viper tuned TCU

Post by Shoppinit » Sun Mar 10, 2019 3:02 pm

All the green wires with other colour stripes going into the TCU seem to concern the tiptro / selector / solenoid. I can't think of anything that would affect how quickly the box changes speed.

Are you sure it's the same TCU that came back after the service?
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."

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Shoppinit
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Re: Viper tuned TCU

Post by Shoppinit » Sun Mar 10, 2019 3:04 pm

When you opened the TCU did it look like one of the chips had been changed / messed with?
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."

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Gav66
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Re: Viper tuned TCU

Post by Gav66 » Sun Mar 10, 2019 3:09 pm

Not that i could see, pic attached. Old boy that serviced it looked after my Audi's and VW cars this was just to much for him I guess.
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20190310_120408.jpg

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Shoppinit
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Re: Viper tuned TCU

Post by Shoppinit » Sun Mar 10, 2019 3:14 pm

Can you explain the symptoms a bit more? When is there this "lull"? In tiptro? Or kickdown? If it's not changing into 5th at 30 and it used to, then that would seem to indicate that the programming is no longer the same as it was. I can't think of anything else that would cause the issue. If there was an issue with speed sensors or CAN comms, then there would be fault codes.
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."

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Gav66
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Re: Viper tuned TCU

Post by Gav66 » Sun Mar 10, 2019 3:22 pm

No fault codes, when I went to pick the car up from him he was panicking with all the lights on the dash and had an obd plugged in trying to get the lights off.when i spoke to unit20 couple of weeks ago they said there was no way he could switch it off. Lull happens in kick down but before it was instant.

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Shoppinit
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Re: Viper tuned TCU

Post by Shoppinit » Sun Mar 10, 2019 3:25 pm

What about 5th at 30?

Can you check the gearbox temp with the Vagcom? Maybe if the sensor is reading low and the TCU thinks the box isn't up to temp then it will hold back a bit.

Also, while you've got the Vagcom connected, check the kickdown switch operation. Make sure the signal is getting there from the accelerator pedal.
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."

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Gav66
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Location: Scotland

Re: Viper tuned TCU

Post by Gav66 » Sun Mar 10, 2019 3:33 pm

No 30 at 50 anymore, just changing all the vac hoses on top of the engine just now and once everything back together I will do those checks. Might be the chips packed in and it's just a coincidence, but would rather check everything first before a run to unit20.

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Re: Viper tuned TCU

Post by Ajc » Sun Mar 10, 2019 3:43 pm

Sounds like the tcu firmware has been flashed to me and it's no longer running the viper tune.
Cheers Al

04 c5 rs6 , Ebony Black, Bare shell repaint , Milltek's, PSS9's,Hotchkis Arb's,Gutted precats, hybrid turbos, Bosch 044 ,And an annoying EML light

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