1.9 Tdi Automatic Limp Mode

[dlt1617]

I've got a problem that I'm looking for ideas on what to try, the 5 speed auto in my Galaxy has a problem with going into limp mode but it's not quite as straight forward as that (Oh I wish it was!)

If the car when started it is in limp mode you can gently pull away and go off down the road gaining speed and it seems sometimes to change into too high a gear causing shuddering through the car and the revs to drop and then changes gear again until you are at a speed where you can select 5th gear using the tiptronic function, not always but its seems more times than not it will allow you to change down the gears (using the tiptronic function) and then as soon as this happens it drives fine again (until the next time it goes into limp mode).

When the car goes into limp mode when driving normally it seems to be when slowing down so the box would be changing from 3rd to 2nd or 2nd to 1st and the if you do the same as above after gaining speed with the tiptronic it will then clear and drive again ok.

Something quite strange is I have driven the car on the tiptrnic function making sure the gears are selecting properly and then parked the car and then gone back to it the following day and it's in limp mode even though no faults are listed in the fault memory and itwas ok the night before.

The fault memory only shows 00652 gear monitoring, which having spent many hours locking at posts on the internet seems to really mean anything that causes excessive slip so could be solenoids, control unit, valve body or all and any of them!

I've cheched the resistances of the solenoids and they are all within range, I've checked the wiring harness from control unit to gearbox for resistance/continuity all with no problems.

 

I'm toying with the idea of replacing the gearbox ecu or replacing the solenoids N88,89 AND 92 as they change the first three gears the only concern is the solenoids also select reverse which I have had no problems with!

 

Does anyone have any ideas????

 

Also anyone got any of the bits suggested?

 

Best wishes.....I'm now off to a dark room because my brain hurts!

 

Dave

[chrispb123456]

I take it you have checked the fluid level? as you haven't mentioned it.

[dlt1617]

Hi sorry about the delay, I had checked the oil level as far as pulling the level plug out and oil continued to come out even after the amount in the tube had drained out. I drained about 3/4 of a litre out and then drove the car for several days without any problems then just as my daughter was asking does this mean it's fixed it suddenly dropped two gears and then after this a fault has reappeared.

The gearbox shows on vag-com all the gears being selected correctly but the gearbox does not select 2nd mechanical or 5th gear either hydraulic or mechanical. The only fault in the fault memory is still 00652 gear monitoring but I suspect this may be due to shoing 5th gear but the box being in 4th gear.

The gear changes are also harsher than normal.

 

I obtained another ECU off Fleabay to try and the results are still the same (THIS WILL BE BACK ON THERE FOR SALE SHORTLY!)

 

I've checked this link http://forums.vwvortex.com/showthread.php?3469274-09A-Tiptronic-Solenoid-Location-Function for the solenoiods but the solenoid shared for 2nd and 5th is also used for 1st and reverse.

 

Any other ideas other than torching the car would be apprecviated as I love the car but I need it working!!!

 

Best wishes

 

Dave

[dlt1617]

Sorry to bump my own post but I've got a better idea of what the gearbox is doing.

 

It pulls away correctly in first gear, changes to second and then changes straight away to third (this happens even in tiptronic).

This change to third takes place not matter the road speed and can only temporarly be stopped by keeping the throttle floored to kick down but even then it still changes early to third. When you release the brake to pull away there is a slight pause and the it jolts into first, the 2nd to 3rd sort of slumps across early and then it thumps into 4th. The gearbox will not got into 5th at any road speed or when using the tiptronic - it's shows the box in 5th on the display but is still in 4th, this is shown as when you select 4th on the tiptronic the revs stay the same. When the display shows 5th gear the revs drop when you back of the throttle as it should do i.e. the engine revs are not locked to the gearbox, when 4th is selected (tiptronic) it is locked so you can use engine braking as it should do.

 

So in summary:

 

Thump when pulling away and the change 3rd to 4th - Down shifts are smooth

Selects 2nd but then 3rd straight away not matter what the speed(even in tiptronic but still shows 2nd on display)

No 5th gear

Display in tiptronic shows selected changes from gear lever but not staying in 2nd as above and no 5th even though shown as in 5th!

00652 only fault shown in fault menory

 

 

Work done already with no improvements:

 

Swopped gearbox ecu

Replaced gearbox oil and N93 valve.

 

Any ideas anyone????

 

Best wishes

 

Dave

[chrispb123456]

Just had my box overhauled for the jolt/delay pulling away more so when cold, there is a piston inside that gets a hairline crack, pressure is lost through here.

Also had slight slipping in fifth.

May be part of your problems.

[dlt1617]

Thanks for the suggestion....but the gearbox is smoother when cold and the delay/thump harsher when warm - also 5th gear is non existant even though the car shows everything to say it is in 5th and if you chenge down on the tiptronic from an indicated 5th (actually 4th) it dips the revs slightly ready for the change but does nothing.

 

I don't suppose anyone got a gearbox for one kicking around????

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Best wishes

 

 

Dave