A8 Transmission in limp mode...opinions?
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A8 Transmission in limp mode...opinions?
x/post from Rocky Mountain region. Also looking for anyone with a Vag-Com near Boulder, CO
New Transmission filter and fluid did not solve problem. All gears on the dash are highlighted. I'm wondering if there is a way to reset the TCU or ECU. Perhaps a re-metering of the transmission inputs would revive it out of limp mode. Currently the reverse gear seems normal, torque-y and fine..but the drive gears feel under powered. I'm assuming this is from the limp-mode state it is in.
Prior to this I was getting a slight shutter at around 2k RPMs in 2nd and 3rd while in Drive. Felt like almost a seeking for overdrive when going a steady speed. It worked fine when accelerating or in 4th when the cruise idle was above 3k RPMs. Also at idle it was a bit rough. I attributed that to the engine though.
Someone suggested that perhaps the Torque Converter needed to be flushed out. Any opinions on this? I've removed a transmission from an A4 before. I'm debating on lifting this A8 up and taking it out to have a look. But my concern is if i remove it and can't find the problem myself then would a shop be able to diagnose the problem with it removed from the vehicle. And would this save much money? What do you guys think?
Any information or opinion is greatly appreciated,
-Chris
New Transmission filter and fluid did not solve problem. All gears on the dash are highlighted. I'm wondering if there is a way to reset the TCU or ECU. Perhaps a re-metering of the transmission inputs would revive it out of limp mode. Currently the reverse gear seems normal, torque-y and fine..but the drive gears feel under powered. I'm assuming this is from the limp-mode state it is in.
Prior to this I was getting a slight shutter at around 2k RPMs in 2nd and 3rd while in Drive. Felt like almost a seeking for overdrive when going a steady speed. It worked fine when accelerating or in 4th when the cruise idle was above 3k RPMs. Also at idle it was a bit rough. I attributed that to the engine though.
Someone suggested that perhaps the Torque Converter needed to be flushed out. Any opinions on this? I've removed a transmission from an A4 before. I'm debating on lifting this A8 up and taking it out to have a look. But my concern is if i remove it and can't find the problem myself then would a shop be able to diagnose the problem with it removed from the vehicle. And would this save much money? What do you guys think?
Any information or opinion is greatly appreciated,
-Chris
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Yay...may be just sensors or electrical
Ok I went to wolfsburg autowerks in Boulder, Co (highly recommend them). Mark there connected his VAG-COM and got some codes for me. Very strange codes but this is what we got.
17090 - transmission range sensor
Sensor # F125
Status - Implausible Signal
17095 - transmission fluid temp sensor
Sensor # G93 - Implausible Signal
I've tried to find some information on the first one so far. Looks like it's a harness inside the transmission. Located where the transmission filter is. I'm having difficulty hunting down an actual OEM part number. Or a diagram of what exactly I'm looking for. Any...and i mean any info would be greatly appreciated. Mainly I just need a part number and some pointer of where they are located and I think I can get this beauty stably back on the road.
Mark cleared my codes and the trans is out of limp mode, but for how long, I don't know. It's driving but with the same previous symptoms.
17090 - transmission range sensor
Sensor # F125
Status - Implausible Signal
17095 - transmission fluid temp sensor
Sensor # G93 - Implausible Signal
I've tried to find some information on the first one so far. Looks like it's a harness inside the transmission. Located where the transmission filter is. I'm having difficulty hunting down an actual OEM part number. Or a diagram of what exactly I'm looking for. Any...and i mean any info would be greatly appreciated. Mainly I just need a part number and some pointer of where they are located and I think I can get this beauty stably back on the road.
Mark cleared my codes and the trans is out of limp mode, but for how long, I don't know. It's driving but with the same previous symptoms.
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Solution??
this was more than nine years ago! Did you ever figure it out? There’s never a solution with these old threads. It’s like all the people commenting disappear forever! What was the prognosis doc? You still around??
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With a D2, it's almost always a transmission rebuild that is required. Either the forward clutch basket of the F clutch fails. Given that a few people (including Tozo) suggested that a rebuild is needed, I'd suspect that was the case.
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Often the car with a blown trans is scrap or sold cheap "mechanic's special" and the user does not bother to come back and close out the thread. Unfortunate but understandable.
You can look for newer posts from the user via the link in their username under "Statistics" to see if they came back after the trans issue.
If a trans has not blown up yet, you can often avoid that with the TransGo valve and possibly a lower valve body replacement, this prevents the pressure spikes that cause oddness, rough downshifts, etc. and eventually something broken or a seal blown out. Search this forum for more detail.
-Joel.
You can look for newer posts from the user via the link in their username under "Statistics" to see if they came back after the trans issue.
If a trans has not blown up yet, you can often avoid that with the TransGo valve and possibly a lower valve body replacement, this prevents the pressure spikes that cause oddness, rough downshifts, etc. and eventually something broken or a seal blown out. Search this forum for more detail.
-Joel.
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