I have a 964 Tip. Problem is just lately the thing has been jumping around eratically and doesn't seem to change gear properly. With Masses of power loss when trying to get the right gear of the line.

I have just totally serviced the gearbox with a new filter, oil flush etc. And the problem did not go away.

On plugging in one of those Bosch Diagnostic Hammers the fault code Speed Sensor Faulty appeared.

Where on earth is the speed sensor and where can I get a replacement? My mechanic seems to think it is referring to the ABS speed sensor mounted in the front wheels, but I do not want to make a costly mistake.

Does anyone have any ideas?

Thanks

D

 

It is not the ABS sensors. Mounted into the underside of the transmission is a pulse speed sensor. Every tiptronic is so fitted. You cannot miss it. It is quite large, black and silver in colour. I suspect that the connector is damaged but you will not know until you get underneath and remove it and check it out.
I think your mechanic needs to get himself a copy of either the workshop manual, Vol III and or a copy of the 1990 Tiptronic service information manual.
The senders are available from your local Porsche stockist.
Ciao,
Adrian
911C4

PS: There is a speed input from the ABS to the tip control unit. However if you have a failed ABS speed sensor you will also have an ABS warn light on. The ABS speed input diagnostic failure is not speed sensor fail either.

 

thanks for the info I will check it out in the morning