john007

So I have a Porsche 981 boxster 2014 around 40k milage on it with pdk. I left the vehicle in storage for awhile with a battery tender. I recently just came back and when I started up the car I had a warning light that came on start stop deactivated and Transmission malfunction not able to put into reverse. When I shift gear into reverse the light starts to blink on the R on the dash. I thought nothing of it rebooted the car and it seem fine. Then drove it for about 5 miles out and the at a red light the car started to struggle and then engine shuts off and the instrument light all turned on and flicker. Put the car in park and restarted the vehicle and everything was fine. I thought maybe old gas and the vehicle may just need to joy ride run. The car ran fine for about another 10 miles. Same issue 3 other times through out the day. In the parking lot reversing it is a miss or hit on the malfunction with transmission error showing up on the instrument cluster. I got the vehicle home and plugged in a scanner. The scanner showed error in tiptronic transmission control which throws out code p0843 “pressure sensor 1 (clutch 1), short circuit to b+” any idea where that pressure sensor 1 is located at or even where to look? Any idea if this is two different issues or can be cause by same issue? Also, start stop I made sure it is disable but at a red light when the car dyes it feels like that when the engine is cut off but with flickering instrument cluster light.

Prairiedawg

First thing I would do is change the battery or at least test the voltage. Interesting code, you may actually have a short in that circuit. Short circuits cause all kinds voltage issues. Start with a new battery and go from there.

john007

Battery is around 14 while running and 13.4 while off. Swapped the battery out just to swap because it is still under warranty. Code still there. I just sucked all the gas out of the tank and added new gas as well and still the car will shut off randomly and code is still throwing p0843. And transmission malfunction error code for the reverse.

byroncheung

@john007 did you get down to the bottom of it?
I found this thread on 2carpros.com (it's a panamera with pdk), his car was throwing p0843 intermittently, and it turned out to be a harness issue. (I'm researching my intermittent pdk problem as well and came across that and your thread).

mcsirius

hi guys, found this old thread. I have a 991.1 4s. Recently replaced valve body. Did the recalibration and re-programming. It went alright. However, after it came off the lift, the transmission shuts R,1,3,5,7 again for code P0843, when I tried to manual shift from 3->4. Re-did the programming, everything seems to be normal again. Drove for about 50 miles with no issue. As soon as the rpm goes around 5000 rpm, same issue comes back again. Initially I thought it might be that sensor erroring out, because 5000 rpm shift is pretty aggressive, however, when I put the car into P and rev it to 5000, the error comes back again. I'm at a dead end where nobody really knows what's going on. Don't want to throw the car to dealer cuz they will just tell me to replace the entire block for $20k. Please help

sh.errr

Im having same issue which I turn on it either doesnt turn on or turn off in few seconds or when moving and on brake!
I changed the battery and ignition coils (after market) but again same problem!
Mechanic told me its not fuel pump problemB
First error was reduced engine power then engine light was showing!
They reset the system which showed the issues and remove and put new battery again but still seems like some sort of electric problems!
Panamera S 2013 model 85000km

john007

I still can not figure out the problem any suggestions? I have swapped out the transmission fluid several times already. Clean the transmission solenoid, then I ended up buying the solenoid from Sheng Hai auto where everyone is saying they are getting their solenoids. Then I got someone out to code it and was unable to code it. The new solenoid did not show any ability to shift gears on the instrument cluster. So I was recommended to get a new TCM from the coder and I bought a new TCM and it was coded and did not work. The instrument cluster did not show the red dot for different gears when shifting. Then ended up swapping back to the old solenoid and kept the new TCM module and same code still. Currently i used a scanner and checked the pressure regulator current Actual Value (mV) 1 - 7 = 47.8, 48.2, 849. 536.6, 44.8, 44.0, 0.0, respectively. I am not sure why 7 current is 0.0 and why 3 and 4 are so high? Pressure sensor 1-3 actual value (PSI) : 12.6, 23.96, 0.00, respectively. I also see activation of shift lock solenoid: inactive??? Any suggestion would help.