A while back my transmission started shifting weirdly and occasionally making the clanking noise while shifting. The PRND lights would all light up on the dash display too. I must say that I was nervous at first, thinking that I was going to have to replace the transmission. This started at the beginning of a 700 mile trip but it made it back home ok.

I did some searching and reading on the different Cayenne forums and found out that more than likely I was going to have to change out the valve body or transmission computer. I decided to first try a fluid change and ordered some fluid I had read about. Anyway, before I changed out the fluid, I went ahead and pulled codes with my Durametric and found several. Engine codes were B3901 - Evap Sys incorrect purge flow, B3D08 - System at Idle Bank 2, P1909 Air Leak between MAF and Throttle Body. Transmission had 1 code and it was 1314 - DME control module

I cleared the codes but they all came back as well as the transmission issues still happening. I looked through the engine compartment for any loose connections in the piping and hoses and ultimately found a cracked hose that runs across the top of the engine near the throttle body. The hose is thin plastic and is corrugated (looks like large diameter wire loom). So, I replaced the cracked hose with a rubber one I found in my garage. I cleared the codes again and took it for a drive. It drove perfectly and has since While I still have the CEL lit for the purge flow issue, it does not cause any driveability issues. I didn't even bother with the fluid change, I'll save it for later.

I did find another thread where a guy was having these transmission issues including the PRND and he said his was all fixed by changing out one of the emissions valves that the airpumps feed into. So, my point is that other issues outside of the transmission may be causing the transmission computer to do weird things to the shifting. Hope this helps someone in the future.

 

There is wiring harness that plugs into the transmission. Fluid may leak into the harness and fill up in the connector. The dealer and another independent shop have both told me it is common to see this issue on Cayennes. When the pins are submerged in transmission fluid, you may experience some weird behavior and get error codes triggered. The fluid leak may just be a trickle, but accumulates over time. When you unplug the connector, you'll likely see fluid coming out. Not sure if the above is the root cause of your problems, but it's worth checking out. Simply start by unplugging the connector and cleaning the pins.

 

Following you Legedary from each forum but hey......lets try to pin down a punch of list of what to check before initiating an expensive repair.

I apprecaite the help as my cayenne feels like I am power slamming it as I go down the road.

 

The transmission fault code (1314), essentially means that there is a fault code in the DME that's affecting the transmission (rather than an actual transmission fault). In this case, the air leak between the MAF and throttle body was throwing it into limp mode.

 

THROTTLE BODY! Felt like my car was going to EXPLODE during upshifts. You have to drain the fluid anyway, so toss in a new transmission filter.

It is an exspensive part $1500-1700 but mine seems to be fine now--more than 40,000 miles later.

 

Gr8ful what did you mean bt throttle body? And what are you doing to the tranny to have to replace the filter anyway?
i have the 1314 dme code and trying to make sense of what fixed it here for everyone, thanks