TCU

4.2 V8 40v biturbo - 450 bhp
4.2 V8 40v biturbo - 480 bhp (plus)
Hixrs6
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TCU

Post by Hixrs6 » Mon Nov 09, 2020 3:47 pm

Hey guys,

Anyone know how to log TCU currents or anything like it via vag com?

Had a solenoid code and replaced all the solenoids and still have the code. Want to try everything before just buying another TCU.

Thank you!

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Shoppinit
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Re: TCU

Post by Shoppinit » Mon Nov 09, 2020 3:58 pm

Logs measuring blocks 005 and 006 along with group 001 to get the input rpms and current gear.

Remind me what your error codes are?
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."

Hixrs6
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Re: TCU

Post by Hixrs6 » Mon Nov 09, 2020 5:14 pm

Shoppinit wrote:
Mon Nov 09, 2020 3:58 pm
Logs measuring blocks 005 and 006 along with group 001 to get the input rpms and current gear.

Remind me what your error codes are?
Thank you sir.
362A1D60-17E9-4C35-B20F-82D2F7975E66.jpeg

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Shoppinit
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Re: TCU

Post by Shoppinit » Mon Nov 09, 2020 6:27 pm

So many fault codes that could all be explained by a bad 16-pin connector at the gear box. Or a bad TCU.

How do you feel about measuring resistance?
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."

Hixrs6
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Re: TCU

Post by Hixrs6 » Mon Nov 09, 2020 8:52 pm

I measured the resistance on the harness at the front that’s known to corrode because of the seals
2AE9D50F-76F5-4DDC-91DC-0D79A04EC65F.png
And it was fine. Used contact cleaner and reconnected. I haven’t been able to find a spare TCU to try out I live in Canada and there’s not many of these here

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Shoppinit
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Re: TCU

Post by Shoppinit » Mon Nov 09, 2020 10:49 pm

Plug it back in and unplug from the TCU to check the resistances.
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: TCU

Post by Shoppinit » Mon Nov 09, 2020 10:56 pm

Measure between pins:

52 & 53
33 & 52
33 & 34
32 & 52
32 & 34

Ignition off.
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."

Hixrs6
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Posts: 34
Joined: Tue Jul 03, 2018 6:02 pm

Re: TCU

Post by Hixrs6 » Mon Nov 09, 2020 11:55 pm

Shoppinit wrote:
Mon Nov 09, 2020 10:49 pm
Plug it back in and unplug from the TCU to check the resistances.
Thank you very much I’ll try that tonight.
Testing the pins attached to the harness that you pull out of the TCU correct?

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Shoppinit
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Re: TCU

Post by Shoppinit » Tue Nov 10, 2020 9:35 am

Yup.
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."

Hixrs6
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Re: TCU

Post by Hixrs6 » Tue Nov 10, 2020 5:01 pm

52 & 53 nothing
33 & 52 28 ohms
33 & 34 nothing
32 & 52 27.7 ohms
32 & 34 nothing


Couldn’t do the logs because I can’t get it out of limp mode right now even after clearing codes etc.

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Shoppinit
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Re: TCU

Post by Shoppinit » Tue Nov 10, 2020 6:01 pm

When you say nothing do you mean zero or infinity?
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."

Hixrs6
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Posts: 34
Joined: Tue Jul 03, 2018 6:02 pm

Re: TCU

Post by Hixrs6 » Tue Nov 10, 2020 6:53 pm

Shoppinit wrote:
Tue Nov 10, 2020 6:01 pm
When you say nothing do you mean zero or infinity?
It says “1.” on the screen when it’s on but you’re not using it and when I test between those three pins, the screen doesn’t change

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Shoppinit
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Re: TCU

Post by Shoppinit » Tue Nov 10, 2020 7:01 pm

OK. Then infinity.

So what you measured is all as I would expect it to be.

That would suggest it's not the 16 pin connector and not the solenoids. So maybe a bad TCU.

Where in Canada are you?
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."

Hixrs6
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Posts: 34
Joined: Tue Jul 03, 2018 6:02 pm

Re: TCU

Post by Hixrs6 » Tue Nov 10, 2020 7:21 pm

Shoppinit wrote:
Tue Nov 10, 2020 7:01 pm
OK. Then infinity.

So what you measured is all as I would expect it to be.

That would suggest it's not the 16 pin connector and not the solenoids. So maybe a bad TCU.

Where in Canada are you?

Niagara Falls Ontario.
My tuner said he would be able to take apart the TCU and diagnose and fix if he can for around C$400 although I don’t really see a very good track record when people Muck around with the tcu

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Shoppinit
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Re: TCU

Post by Shoppinit » Tue Nov 10, 2020 7:33 pm

You could try calling Xemodex to see if they can do anything. They’re in Ontario IIRC. I don’t know if they do anything on the RS6 TCU though.
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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