1.2 tdi [ANY]: skipping gears

[RAB3L]

Hi Aamir,

 

Might be a gearbox problem. Do you still get the 00297 code after deleting the faults? There is a general problem with the gearbox in that they (or some) were built with excessive preload on the output shaft bearing, resulting in eventual failure. This causes the clearance between the gearbox speed sensor and the gear that it is monitoring to become excessive, causing it not to work. If there is a mis-match between the engine revs and the output shaft revs, the system shuts down, as you describe.

 

RAB

[Lupo_3L]

Not really. The gear ratio does not change with tittle clearance, nor with too much. Just had the pleasure of transmission failure. No faults despite the gears eating the bearing. 

[RAB3L]

From here: http://www.volkspage.net/technik/ssp/ssp/SSP_221.pdf

 

"The gearbox speed sender measures the rota-

tional speed of the gearbox input shaft.

Using this Information and the road speed sig-

nal, the gearbox control unit can determine what

gear is selected and the extent of clutch slip."

Had the same fault codes when my wife's Lupo 3L failed with the same symptoms. The G38 was tested on another 3L and found to be OK. It's a Hall sensor; they rarely fail.

RAB

Bearbeitet 28. Dezember 2018 von Artur
Unerlaubten Hyperlink entfernt

[Lupo_3L]

Still a worn out bearing doesn’t affect the rotation speed of the transmission. 

[Phoenix A2]

vor 15 Minuten schrieb Lupo_3L:

Still a worn out bearing doesn’t affect the rotation speed of the transmission. 

 

I think RAB3L wants to point out that it can happen that the G38 speed sensor gives wrong values due to too much clearance.?

[RAB3L]

Yes, absolutely.

 

RAB

Bearbeitet 28. Dezember 2018 von RAB3L

[Lupo_3L]

Just that the G38 sits on the opposed side of the bearing.  Besides it does not make any sense while during shifting gears would be skipped due to a missing signal. Ist would much more goe into limp mode.