[siberian]

PLEASE NOTE THE FOLLOWING FOR ALL 2008 V6 or V8 (don't know if it applies to all T2s)

If the differential selector switch is WITHOUT a lit selection (meaning either HIGH or LOW), on a 2008 whether V6 or V8, it seems that this signals that ALL memory settings have been lost.

Please note this could have NOTHING to do with the switch being defective (as I initially thought) but is a signal that the TCM no longer knows what the hell it's supposed to.

At that point I surmise that the tranny goes into safe mode and I would NOT recommend towing anything until you have the TCM module re-flashed.

siberian

 

[terrywood02]

So odd! We are in the same situation, but my differential selection was working correctly before it hit the shop.

 

[siberian]

Very weird as my V6 is in the shop for the last warranty work and I asked them to change the switch as I suspected a burned out bulb. Coincidentally I asked them if they had to remove the center console to get the switch out, they said no, the TCM had lost all settings which is why the selector was not on. As soon as they VASed it, the light came back on. Whereby my post.

Very weird.

siberian

 

[Yeti]

That will teach you to mess with the tranny coding!!

 

[siberian]

Well that's just the point the V6 was not touched! There was no low voltage, nor was there anything Vagged on that vehicle for over a year if not more yet...

What I can't remember is when or whether the light on the V8 went out, meaning if it happened at the same time as the coding... But the V6 wasn't touched.

siberian

 

[volkswagendude]

Siberian, I was always under the impression that on all VAG's with Tiptronic, when the TCM goes into limp mode, all the gear display characters in the dash light up with an all red background or whatever its display colour was meant to be. When this happens, the gear you are in is not highlighted in the display. Did this happen to yours?

Also, is it possible that when the dealer scanned it, it reset itself? I've come to realize, that at some point, most electronic module type gizmos just need a reboot at some point in their lives to act normal again.

 

[siberian]

No. The display is normal other than it does NOT show D1, D2... on the V8. On the V6 nothing was touched and the gear display was normal (monochrome MFI).

However, it does sound reasonable, that when it's in limp mode, the diff selector should no longer light as it doesn't receive any signal from the TCM.

I also scanned it but you just get nothing other than "no response from controller". You can't poll it as it's not there. You need to send a command to it to wake it up. Uwe bought a TCM module the same series as mine to try and see if he could trick it, but so far I've not heard a word from him.

So yes, it needs to reboot, but as it is the VAG-COM can't do it.

As to the V6 the dealer thought it was a battery issue, but the battery has been fine and no error codes were logged or pending. Just weird. But it does make sense, if your TCM is in neverneverland it won't show whether you're in HIGH or low. As for flashing all gears except the one you're in, that's maybe on the T1s.

siberian

 

[volkswagendude]

This is what my ex 2005 Passat's display would look like when in limp mode with red monochrome display.
It would not always do this, and in the end, proved to be an intermittent connection problem, probably either a loose connection, corrosion, who knows, I learned to live with it.

 

[siberian]

Yep, T1 not T2... which is why on the title I put 2008 (not even wanting to venture ALL T2s)

siberian

 

[volkswagendude]

Yep, T1 not T2... which is why on the title I put 2008 (not even wanting to venture ALL T2s)

siberian

Not sure I follow on the T1 or T2 thing???:-s

 

[siberian]

You mentioned ALL tiptronic VAGs display this and then you show me your 2005 Passat. Equivalent in the Tregs is a T1 (2005). As far as mine (2008 ) are: the display is normal.

siberian

 

[siberian]

As a last (interesting) note on this is the following:

On my V8 when I put it on LOW, the MFI registers it and displays "Off Road selected" but the indicator is still off on the selector switch. Thus the MFI must get the info first and then passes on to the TCM.

In any case, if one is to infer from VWDude that his thoughts were that all VAGs with Tiptronics display all gears in red, this appears to be for the T1 series with Tiptronics unless of course both my 08s are a one off.

If I come across any more info I'll post.

siberian

 

[volkswagendude]

Well not all in red, the key word here is highlighted. I mean my T1 MFI is the coloured one, just like yours is, where the gear characters are in that off-white colour. I've often wondered so how would it render itself if the tranny went into limp mode, and I'm guessing all the gears would be highlighted in that same off-white?

Of course, quite possible that there would be no highlighting at all, and also possible that my T1 colour MFI would indeed highlight all the gears should it go into limp mode, and your T2's display would not.

All hypothetical at this point, but great from a technical standpoint to get some answers.

 

[siberian]

Well from what I've been able to diagnose, the tranny controller simply reverts as though it came straight out a box. It has no code in it whatsoever. I would surmise that as it has no settings, it's not really controlling anything electronically. It is polled by the ECM, receives nothing and just bypasses the TCM (or has some basic code) and life goes on.

The reverse display (rather than RED) was simply what I termed it and it seems to be something on the T1s. As I said, if I select LOW it does register on the MFI but since the TCM is "off line" it just reverts to the equivalent of braking if your ABS dies. Your brakes still keep working just not in ABS mode. That is I believe what happens. It can't totally render you gearless it's just not electronically controlled anymore.

siberian

 

[Kelly Lowman]

PLEASE NOTE THE FOLLOWING FOR ALL 2008 V6 or V8 (don't know if it applies to all T2s)

If the differential selector switch is WITHOUT a lit selection (meaning either HIGH or LOW), on a 2008 whether V6 or V8, it seems that this signals that ALL memory settings have been lost.

Please note this could have NOTHING to do with the switch being defective (as I initially thought) but is a signal that the TCM no longer knows what the hell it's supposed to.

At that point I surmise that the tranny goes into safe mode and I would NOT recommend towing anything until you have the TCM module re-flashed.

siberian

Siberian, I see you’re a rockstar on here and it appears we may have as the same problem (you - had + me have). If I switch the knob, low and high flash and won’t move out of off road.
I am a poor (truly no money) teacher/single mom…any suggestions?
I let my daughter run up to McDonald’s last night…she’s never driven alone and afraid she messed up something that’ll require me to ride the bus to work for the foreseeable future.
I performed the accessory plus hazard lights plus press gas 5x and while that turned off what I actually have a button for, that didn’t fix.
also performed accessory plus gas pedal all the way to the floor for one min reset. (A no go as well.)
I’d truly appreciate any advice.
thx much.
kelly

 

[siberian]

Hi Kelly, sorry my post is like 14 years ago and I'm not often on this Forum. Your best bet is to have the car scanned at an Indie shop. Also please state what year, engine etc. your car is that will help folks trying to help. At this point it could be anything from battery to TCM to ... post back when you get your car scanned. Good luck

siberian