Cayman 981 - reverse gear not available - pdk

[Pdclarkson]

Hi all,

Has anyone come across this error. "Reverse gear not available, ok to drive on”?
Prior to this there was no warning signs anything was up, car was driving beautifully on the drive back from Goodwood. Went to move the car on Sunday and the message popped up, car wouldn’t go into reverse. I thought this must be the car having a wobble, so I left it for a while and tried again, same issue.
Called a local garage and managed to take the car in, only 2nd gear was available! after running diagnostics one of the sensors was reporting not enough voltage, should be 5v but was fluctuating between 3v & 4v. Other sensors were reporting correct voltage

Does anyone have any advice in this. Porsches answer is to replace the entire gearbox

Model: Cayman S - 2013

Thanks Paul

 

[Motorhead]

Sorry to hear about your problem Paul, especially since it was completely unexpected. Unfortunately I can’t throw any light on the subject other than to say that it sounds like a control fault rather than a fundamental mechanical problem with the transmission, but that’s just an uneducated guess. You’ve mention a sensor low voltage, so maybe it’s just a sensor fault?

You don’t say whether or not the local garage was a Porsche specialist but the problem needs to be diagnosed properly on a PIWIS or equivalent analyser which will identify any faults. I believe that it’s possible to perform a software reset of the control module which might clear your problem.

Just note that these cars are very sensitive to battery condition, and a failing battery can lead to all sorts of electrical problems. Sometimes disconnecting and reconnecting the battery can give a positive result, which is something simple that you could try.

Jeff

 

[Pdclarkson]

Hi Jeff, thanks for your reply. The garage is a local Porsche specialist and I believe the analysis is PIWIS. I did ask the garage to check the battery and they had connected a new/known good battery, cleared the codes and were able to take it for a drive. However, after a few minutes the same error came back. The car did mention low voltage once before, but that was many months ago so I assumed everything was ok. Do you know what the voltage should read on the dash if the battery is good?

Paul

 

[Motorhead]

I don’t know how accurate the dash voltmeter is but using a multimeter across the battery posts a battery in good condition should show more than 12.6V open-circuit, increasing to about 13.7V-14.7V with the engine running and charging the battery. If your specialist replaced the battery and still had the problem you’d assume that your battery is OK.

The fact that the transmission worked for a while when the codes were cleared suggests that it’s working mechanically and that the problem lies with the electronics. If your specialist is able to replace the sensor which is showing a low voltage reading that would be a sensible starting point. Hopefully it’s external to the transmission because if it’s internal, unless it can be accessed by removing a cover I suspect that would prove to be problematic because the PDK transmission is a "non-service” item, requiring a replacement unit at very high cost.

Because in practice it’s a non-repairable item, I wouldn’t think that most Porsche specialists can help with PDK problems and you may have to resort to using a Porsche Dealership to progress your problem.

Jeff

 

[StuNo1]

Out of interest was this ever resolved?