Limp mode, first one here with Faultcode 17115(?)
 

Good evening Gents.

Thie old girl is acting up again. Had a trip to the mountains last week and suddenly the christmas lightning was a fact.
PRND432 and the car had apx the same power as an 2CV :rolleyes:

Stopped an restarted and it was gone, tried to punish the car a bit in order for it to return, but it stayed away. well all goods thing i thought.
The gearbox shifts as smoothly as always.

2 days ago, while enterening R and engaging the gear smoothly followed by a very short feeling of it slipping for a microsecond. Put it back into N and back into R. shifts smoothly, but after apx 2 second there is a slight feeling of it slipping. Tried 10-15 times and the exact same happens everytime.

I have tried backing up immediatly after the gear is engaged(before the tiny slip is noticed) and it backs up like a prince..

So i finally today i had the chance to do the VCDS and check for fault codes.

Just gonne post those from engine and gearbox. The ones related to the engine i had back in August 2016, but they have dissapeared since (and returned... yeeay)

The once for the gearbox is new and scary..:eek2: Could not even fine any thread in regards to 17115.

The gearbox was conpletely rebuilt apx 50k miles ago, and had the last oil and filter change 20k miles ago.

Mileage: 272810km-169516mi Repair Order:



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Chassis Type: 4D (4D - Audi A8 D2 (1994 > 2003))
Scan: 25 01 03 08 11 15 16 17 18 35 37 45 55 56 57 65 67 75 76 77
02

VIN: WAUZZZ4DZYN006218 Mileage: 272810km-169516miles
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Address 01: Engine Labels: 4D0-907-560-AVP.lbl
Part No: 4D0 907 558 J
Component: 4.2L V8/5V G 0004
Coding: 05753
Shop #: WSC 00000
VCID: 346D5D8F043A3BE274-5140
WAUZZZ4DZYN006218 AUZ7Z0X1128479

3 Faults Found:
17549 - Load Calculation Cross Check
P1141 - 35-10 - Implausible Value - Intermittent
17521 - Oxygen (Lambda) Sensor; B1 S1
P1113 - 35-10 - Internal Resistance too High - Intermittent
17539 - Oxygen (Lambda) Sensor; B2 S1
P1131 - 35-10 - Internal Resistance too High - Intermittent
Readiness: 0000 0000

Address 02: Auto Trans Labels: 01L-927-156.lbl
Part No: 4D0 927 156 BN
Component: AG5 01L 4.2l5V RdW 1314
Coding: 00011
Shop #: WSC 02314
VCID: 76E9A78752C669F28A-5140

1 Fault Found:
17115 - Gear 1
P0731 - 35-10 - Incorrect Ratio - Intermittent

As often, Ross-Tech gives you several options:p

17115/P0731 - Gear 1: Incorrect Ratio

Possible Causes
Wiring and/or connections faulty
Sensor Gear Position Indicator faulty
Gear Solenoides faulty
Mechanical failure

Possible Solutions
Check wiring and connections
Check Sensor Gear Position Indicator
Check Gear Solenoides

Faultcodes for the gearbox has not returned yet.
The shifting is still smooth into every gear, revers included

Only noticable difference is that if i put it in reverse with the brake on,I feel that tiny slip after 2 seconds and it only happens once. This however does not happen in the mornings when its cold..

Could this be low oil level?

Most probably the F125 switch. Mine started acting up when selecting reverse and was intermittent just like yours. Someone on here has just posted about an F125 failure after (25? 50?k) miles. Mine at least hit 100k.
The F125 switch would be the item identified as the "Sensor Gear Position Indicator"

17115 means the TCU has noticed a difference between the input and output speed sensors that does not match the expected value for the gear it thinks it is in. Mechanically, that's a clutch pack slipping, as you describe. Not low oil level - in that case the torque converter will start whining well before the clutches slip.

However, given that its been rebuilt, I'd agree with David that the F125 is the first place to look as that is cheaper and simpler to swap as a diagnostic measure than pulling the gearbox out. If that indicates a different gear electrically to what the gearbox is actually doing mechanically that can also trip this code. For example, the F125 briefly indicates 'D' to the TCU, with the shifter actually in 'R'. TCU goes 'whoa we're going backwards when we should be going forwards: wrong gear ratio!'.

On an older gearbox I'd be looking at the A clutch pack, as that's the prime problem area in these. Likely the roller bearing fallen apart, or the clutch basket cracked.

F125 first though as it causes a multitude of weird problems +++

Sorry for the late update on this problem.

Just been on winter vacation and driven the car 500+ miles without any problems. It still "slips" after 2 sec in R with the brake on. The slip is more noticeable if its a steep hill.. I also noted a new funny thing. If i lock it into 1st gear and drive above 3000rpm and i let off the throthle, it shifts into 2nd gear by it self when rpm goes down to apx 1800-2000rpm.. it happens on 3 out of 5 times.:Confused:

So su surely something is not quite right.

For those of you that has had gearboxes slipping in reverse, is there any difference between when the gearbox is cold compared to at operating temp?

The slip never happens when cold.

F125 is on my check list :)

Car still working but its showing more by the week that there is something gone real bad inside the gearbox :(

Since i need the car everyday, i just bough a replacement for the daily drive today, and i'll see in the near future if going manual or sell it "as is" will ne the outcome.
However, i'm proud to show off my new ride here.. It is just so bad ass, and i know you all want one:D

Aren't you taxed on the number of seats in a car in Norway? That's gotta be cheap both to tax and to run!! +++

Gull-wing doors! Oooh! that's a proper sports car +++

More like fly-wing I think :p


Looks fun +++ ... though I'd be a little nervous driving something so small on a motorway or near any trucks.

I Will mostly keep away from the Highways👍

Even my 2 kids finds it funny, and today they showed me where i could park it... Beside their kiddie cars in the livingrom:p