95 A6Q with grinding sounds when in Nutral and Park.

[Franco Barber]

Tyson,
On the 96 A6q, the reverse lights (and the passenger mirror tilt down
feature if equipped) are driven from the
Multi Function Transmission Switch (MFTS).
This switch costs about $180 and is mounted behind the left hand
side transmission mount.  To get to it, you have to support the
engine tranny from underneath and remove the tranny mount.
The MFTS also drives the instrument panel display of selected
gear and the neutral safety switch.
The MFTS is a 5-pole, 7 position switch.
3 poles drive the instrument panel display using a gray code.
1 pole drives the neutral safety switch.
The remaining pole drives the reverse lights/dipping mirror.

The gear pre-selector in the console does not drive those lights.
The pre-selector contains a bowden (??) cable to the
ignition switch which to keep the selector in P unless the key is
in the ignition.
It contains a solenoid that prevents the selector from going into
(R or D) from (P or N) unless the foot is on the brake.
This solenoid is only energized if the key in the ignition switch
is in the run (or start) position.
And it contains another bowden cable that goes to the tranny where
it moves a gear selector.  I am not sure how this cable is attached
to the tranny and how this cable and the MFTS are related to each other.

The noise you describe could be inside the selector itself as the
selector fights against the "foot on brake pedal" solenoid,
or it could be in the tranny as the bowden cable moves whatever it
is that it moves, possibly the MFTS, or I suppose it could be something
else that I haven't even thought of.

The foot on the brake solenoid, by the way, appears to be driven
from the brake light circuit, so if your brake lights are out or
the circuit is having problems the solenoid will not engage or disengage
fully.  So, for example, the famous problem of frayed wires in the
trunk lid causing the brake lights to behave erratically could actually
cause the solenoid to fail to engage or disengage correctly.
This happened recently to a friend's 97 A6q wagon.

Good luck,

Franco



On Thu, Jun 16, 2005 at 12:25:04PM -0700, Tyson Varosyan wrote:
> Hi Guys,
> 
> My dad bought the car earlier this year and it never did have it's reverse
> lights work consistently - we saw the come on once or twice, but by and
> large they are not functional. We pocked around a little and figured that
> with all the fuses and bulbs being OK, the problem is likely to be the
> switch. I didn't have time to help him out with the issue, so today he took
> it to a local shop that works on Audi cars.
> 
> They charged him $40 for an "inspection" and told him that it was likely
> that the switch was causing the problem. He drove home and when parking the
> car found that it now has a grinding sound when shifted into Neutral and
> Park. Everything sounds OK in Reverse and Drive. I have not heard the noise
> yet, but will be heading out that way tonight to see what the heck happened.
> 
> He called the shop back to tell them of the problem that arose right after
> they "inspected" the car and they claim to have touched nothing that would
> cause the issue. Like I said, I haven't heard it yet and do not know where
> it is coming from, but my dad thinks that its coming from the tranny.
> 
> What should I look for? What could the shop have done in their "inspection"
> to have caused the issue?
> 
> Thanks,
> 
> Tyson Varosyan
> Technical Manager, Uptime Technical Solutions LLC.
> tyson at up-times.com
> www.up-times.com
> 206-715-TECH (8324)
> 
> UpTime/OnTime/AnyTime
> 
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> quattro at audifans.com
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> 

-- 
Franco Barber                   feb at febsun.cmhnet.org
95 A6Q w/Gamma CD mit RDS!      Columbus, Ohio  USA
95 A6Q 5spd w/HCB-30 bluetooth car kit!