I have done a fair amount of research and just want some input.

I have been getting the Transmission Fault message the past few months when shifting into gear when cold in the morning, always when shifting into reverse. I would pull out into the street, shut off and start and shift straight into drive and it would go no problem. I had diagnosed that as the rotary switch on the tranny. Without spare time to fix, and being I could always shut off and it would go away, I haven't done anything to it yet.

Driving into work yesterday, I started to get some "slippage" like a normal automatic car that would be low on tranny fluid. When I tried to drive home at noon, I got the Transmission Fault message that I could not make go away.

Hooking up AutoEnginuity, I get:

Powertrain CAN

p1000
p0706
p1722
p1252
p1253

Instrument Cluster

u1260

Transmission Control Module

p1798
p1731
p0706
p1722

In my limited research, p1722 seems to indicate A drum problems. Once I get it home in the garage, what would anyone recommend as my next step.

Thanks.

B

 

Add your model and year info to your signature, it really helps people help you. Since the XK8 and XKR have different transmissions, let's start there.

 

Sorry, didn't realize that wasn't in there.

It is a 1997 XK8 with about 140K on the odometer.

B

 

I think (and I emphasize "think") that P1722 means the torque converter is spinning but there's no output from the transmission. This could be A drum, or the bearing/o ring failure I had, or maybe even a solenoid failure.
I find it very strange that your issue went on over several months. Read all the posts here and almost all of them say it went bang and wouldn't move. The typical symptom is that when leaving a light, it revs very high, then engages with a bang.
Your slippage sounds different me. Keep in mind that I am only an enthusiastic amateur, the only tranny I've ever touched is mine.

 

The slipping happened all of a sudden this week. The prolonged issue I believe was associated with the switch on the tranny associated with the P0706 code.

B

 

How mechanically adept are you? There's a number of threads here where guys have fixed their own transmisions. It's time consuming sometimes but it can be done.
Or, start phoning around shops for an estimate on a repair, or replacement trans.

 

I will be fixing this myself. I have been reading the other threads. I guess what I was asking is if I look at any switches (rotary switch) first or just dive into the tranny fix.

I tried a hard reset yesterday and it did nothing. Upon start up, it did the same slipping inching forward, then upon shifting into reverse, the Transmission Fault light came on. In pulling the codes with just my little handheld, P0706 was the only one to come up.

Yes, this seems like the A drum. But do i have the A drum AND rotary switch problems?

B

 

I'm not sure to be honest. My transmission is also a ZF 5HP24 but it was in my wifes BMW.

Please help, forum gurus!

 

Multiple transmission codes are going to be hard to diagnose, not knowing if they are related or separate, one causing the other. Mechanically, it sounds like something is awry, so I'd start there. While the transmission is out, take off the rotary switch, and clean it...possibly check for its mechanical operation. I don't know if it can be diagnosed on the bench with a meter, but that would be my path. A-drum (physical damage) then re-evaluate after install.

 

Ugh! I was secretly holding out for a magical cure that didn't involve removing the tranny. Looks like the car is done for the year. I have a cousin who owns a shop nearby and will let me use his lift, but that will have to wait until spring. Too many house projects on my list right now. Plus don't want to bust my a.. to fix the car just to put it away.

At least i can take care of a few things with the tranny out...rotary switch, heater pump. Should probably look at suspension as long as it is up.

B