1,2 TDI clutch/ gearbox problems

arno

Member
I am having problem with electronic manual gearbox on 3L A2. Gearbox type is 085. Hydraulic oil has been changed (=enough) , pressure sensor (G270) and speed sensor G38 as well. Most recent and most typical error codes are:

00263 - Transmission
27-10 - Implausible Signal - Intermittent
00841 - Transmission Hydraulic Pressure Sensor (G270)
35-10 - - - Intermittent

After changing gear to (typically) 3rd the system "gives up" =clutch pressed, engine on idle (no response from pedal) and then you are able just to roll. Stop car, switch engine off, put gear selector to N and you are able to continue running until this happens next time (=30sec-5min). This implausible signal error can occur when gear is on E, D or tiptronic. Ambient temperature has been between +5...-10'C. Clutch has been adjusted to 1,86V (recommended 1,8-2,0V), basic settings OK, creep point OK.
Any suggestion for reason?
- Worn out, slipping clutch? 2002, 177.000km driven and most likely original clutch. If clutch would slip, it could give unsyncronized signals between engine and transmission. By feeling the clutch is not slipping...
- electrical problem? where and what kind?
- hydraulic system, magnetic valves?
How to fix this?
 
I believe that you have a poor electrical connection somewhere. You can produce the 00841 code by simply unplugging the hydraulic control unit. I would check the connector.

How many gear changes can you make between the pump stopping and starting in tiptronic mode, engine not running?

RAB
 
I have checked connectors few times, but no visible damage. Just 2 gear change at tiptronic mode. Unplugging connector next to hydraulic unit would give also open circuit.
What would be error codes if clutch would be slipping? And how much of slip does to gearbox computer allow?
Arno
 
Last edited:
Here for clutch error codes:

http://wiki.ross-tech.com/wiki/index.php/17119/P0735/001845

although they do not specifically relate to the 085.

Is there sufficient hydraulic oil? Is there sufficient pressure - the pressure could be limited by the condition of the accumulator which is charged with nitrogen above it's diaphragm. The nitrogen permeates through the diaphragm with time.

Doesn't sound like the clutch slipping - no codes and I'm not sure that you can do a basic setting with a worn clutch.

RAB
 
With the ignition on, foot on the brake and the engine NOT running, in tiptronic mode can you change into all five gears? If not, then possibly a basic setting is required or a new gear actuator. If only 1-2-3, can you change quickly between them without restriction or cannot the pump keep up? If not then possibly a new accumulator is required - was a cheap replacement until recently!

Do not skip loosening the gearbox linkage and re-tightening it during the basic setting. Also check the connections to the gearbox controller under the floor in front of the driver's seat.

RAB
 
Basic settings ok, can go all 5 gears, but then hydraulic pump is running almost all time. When I last did basic settings I skipped the loosing and tightening of gear linkage.
I also checked connections to gearbox control unit - all ok, except one broken cable tie in underfloor wires. Function same as before after fixing cable tie. Replacement of battery did not affect anything. Old one had 11,7V after one week at cold ambient temp (-5'C), new 12,6V at same temp.

When replacing pressure accumulator (which I will do once I have the part), is there some point where to release the pressure? Torx bolt at hydraulic unit body, located in electric connector side?
Arno
 
If the pump is running constantly, it suggests that the accumulator cannot store sufficient pressure (or less likely, a faulty pump).

Disconnect the control unit plug and undo the accumulator with a 24mm spanner (flat at the top) half a turn. That will release any pressure and show the true oil level in the reservoir. Alternatively use a oil filter chain-type wrench to turn the accumulator as it is not very accessible and the flat may be in the wrong position. Change the accumulator and top up the oil if necessary. Plug in the control unit and hopefully that's that!

RAB
 
You may need to do a repeat basic setting. Without the engine running, instrument indication of 4th or 5th gear may be misleading. Don't skip the linkage adjustment. Sounds like you need a new accumulator anyway.

RAB
 
New pressure accumulator installed. At tiptronic 4 gear changes (earlier just 2) before pump starts to run. Basic settings and linkage adjustment done. Seems that everything is now OK and after 35km of test drive I could not repeat earlier problems. Thanks for advices. Arno
 
A2 clutch problems and no solutions.

I have had the car on Audi dealer 3 times now and they can’t fix the problem.
I have the same problem like ARNO who you helped by recommend changing the accumulator.
I have spent ca +1000 euro now and the problem is not leaving me.
I start the engine, wait until the hydraulic pumps stops, ca 30sec and drive away. My problem is that the clutch gives up" =clutch pressed, engine on idle. The problem starts when I stop the car for a traffic light or so or turn the gear selector fast from D to R and when I’m stamp the gas pedal nothing happens, and when put gear selector to R,N,D or Stop the engine is running on idling, nothings happens, I can only turn of the engine by the key and start the engine by hawing the gear selector in N, but I can’t drive, the clutch still won’t work. And when I try to start the engine again it won’t start in stop select the only way I can start it N mode, and the clutch won t work or by disconnect the battery for a few seconds. And then I can start it again and its running normal for 5min to 3 days and the problem is back again (only work driving when I disconnect the battery).
Audi workshop has changed the accumulator, and shect for leaks in the hydraulic tube, end change some gasket.
Before I change the accumulator I can only change max 2 gears before the pumps starts, now I can change 4 gears in manually test.
When I ask the Audi workshop about error codes the say that it has no error code.
Because it’s a big problem for me when the car stops in a traffic lights a try to make an temporary solution by make an switch, circuit breaker from the battery with a cable to the driver seat and I switch, but when I do so the engine starts buts its impossibly to the clutch to work, so I change back again, I only have 10mm2 cable, so maybe the problem Is the volt from the battery is to low when I do so.
I have a Tudor (god quality) 6 months old battery.
Please ansver to my desperate my question!
 
Similar issue

Hi,

I had a similar problem - see my other post. Finally garage found defective hydraulic pressure accumulator system. Had tried everything, oil levels, service, gearbox setting, oil level sensors etc etc.

Seems to be ok now.

I have a 1.2TDi ECO

Cheers

Mark
 
thanks, but what did they repair

Hi.
Thanks for the answer,,,but exactly what did they replace/change.
My car has only going 120000km and has bean for repair noow 3 times on Audi workshop $$$$ and they can t solwe my clutch problems.
What did they change by "defective hydraulic pressure accumulator system"
I have change the accumulator, oil level, gasket.
Sorry for my not so perfekt english.
BR
Tomas
Sweden
 
Hi.
Thanks for the answer,,,but exactly what did they replace/change.
My car has only going 120000km and has bean for repair noow 3 times on Audi workshop $$$$ and they can t solwe my clutch problems.
What did they change by "defective hydraulic pressure accumulator system"
I have change the accumulator, oil level, gasket.
Sorry for my not so perfekt english.
BR
Tomas
Sweden

Any fault codes? This happened to me recently, multiple times on one journey (Vienna to Eastbourne!):

http://www.a2oc.net/forum/showthread.php?t=13301&highlight=eco

The codes indicate a poor connection at the gearbox control unit in this case, I would guess. The problem resolved itself.

RAB
 
Dnepr,

I believe Arno had two problems, not much pressure in reserve due to a failing accumulator and possibly a faulty connection or a clutch adjustment was required. When was a basic setting last done (this includes a clutch adjustment)? This should be done every 30,000km. Insufficient hydraulic pressure just prevents the clutch and gear actuators from working, it does not affect the throttle.

With a 1.2Tdi VAG-COM is really essential and very quickly pays for itself!

RAB
 
clutch calibration

Dnepr,

I believe Arno had two problems, not much pressure in reserve due to a failing accumulator and possibly a faulty connection or a clutch adjustment was required. When was a basic setting last done (this includes a clutch adjustment)? This should be done every 30,000km. Insufficient hydraulic pressure just prevents the clutch and gear actuators from working, it does not affect the throttle.

With a 1.2Tdi VAG-COM is really essential and very quickly pays for itself!

RAB

Hi,

to do the basic setting with clutch system, do I need the registered version of VCDS, or I can use the normal downloadable version which is available on Ross-Tech websit?
 
Hi,

to do the basic setting with clutch system, do I need the registered version of VCDS, or I can use the normal downloadable version which is available on Ross-Tech websit?

I think its more to do with the vagcom lead rather than the software. Some of the copy leads using the free V.409 software seem to do just about everything the genuine lead will do and others just don't connect to many of the modules.


Cheers Spike
 
audi a2 3l gearbox electronic problems

I had exactly the same problem with the same error codes. The pump unit was faulty. Does yours intermittently run on continuously when the engine is off? It makes a low purring sound, not nearly as loud as when it is building up pressure.

Unfortunately it took Audi some time to diagnose the problem even after I told them about the pump running on and not building pressure. They needlessly replaced the ECU, clutch, the clutch and gear actuators. After all this the A2 stopped like yours. It just coasted to a halt in neutral and would not restart. Finally they replaced the complete power pack unit and it has operated perfectly for the last 60k km.

I believe the brushes in the motor wear. It will get worse and will ultimately refuse to start.

audia23l
 
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