997.2 Targa 4s PDK issues

cardy · 14 Nov 2019

The initial faults per the 1st shop

U0418 - CAN fault, brake
P0562 - system low voltage (should be noted this fault was stored in April - when the battery was replaced)

cardy · 14 Nov 2019

Comments follow from first mechanic to owner of 2nd shop where car is heading:

2009 997 4S PDK here with a P1733 (shift rod 3 displacement sensor) issue. When the vehicle was first dropped off, when put into D the selection screen would cycle between 1/2 gear repeatedly, with the above fault stored. I monitored measured values and found all ranges to be within spec (including the temperature sensor), with the exception of the shift rod displacement sensors, which did not move when put into gear.
I unplugged the mechatronic and sensor connectors on the PDK to check for oil ingress, no oil was found in connector housings.
At this point, fluid was drained and pan removed to inspect the mechatronic wiring harness, no damage found. PDK control module was disconnected inside the vehicle and tested wiring from the PDK to the module. All wiring found to be ok (within 0.2 Ohms). Lack of wiring faults, shift rod not moving, as well as client's concern of late engagement occasionally led to a Mechatronic unit replacement. Following replacement, coding, fluid fill and bleeding, the gear selector no longer cycles between 1/2 gear, but the 1733 fault returned after being put into D.

If there is any insight you may have it would be greatly appreciated.
This issue unfortunately doesn't seem like it will be as simple as a wiring repair or new mech unit.

deMort · 14 Nov 2019

If the wiring has been checked for any short circuits and found to be ok .. if the control unit has been replaced and still faulty then we are only really left with the sensor as per the fault code .

For me i would have scoped the signal from this sensor at the beginning and then gone from there .

shift rod 3 displacement sensor seems atm to be the fault and if this can be replaced on its own then it's not a new box required .

I'm afraid here and we have very few parts available to fix issues on these hence its often a new box required .

cardy · 15 Nov 2019

the mechatronic is parts 7, 11 and 14, Star Wars shaping

cardy · 28 Nov 2019

deMort said:
If the wiring has been checked for any short circuits and found to be ok .. if the control unit has been replaced and still faulty then we are only really left with the sensor as per the fault code .

For me i would have scoped the signal from this sensor at the beginning and then gone from there .

shift rod 3 displacement sensor seems atm to be the fault and if this can be replaced on its own then it's not a new box required .

I'm afraid here and we have very few parts available to fix issues on these hence its often a new box required .

How do you scope the signal from this sensor ? Isn't the sensor inside the sealed PDK unit? Part #?

There is a guy locally that will fix this for half the price of a new unit ... so he must me able to open the tranny, replace what is likely an inexpensive part (rare to find I guess) and put it back together.

So if he can get the part they must be out there somewhere? At that point it become do you get a new one with a full 2 year warranty or repair and flip the car?

The crazy thing is that Porsche requires the old tranny back before sending a new one

I have sent a message to head office - likely falling on deaf ears - about how asinine it is for a car of this calibre to have such an expensive fix when it is only 10 years old . .The fix is 45% of the value of the car !

deMort · 28 Nov 2019

The sensor will have a signal wire going to the control unit .. you connect a scope to this wire and see what values it reads .

A PWM signal will be between 10 volts and about 2 volts with anything above or below that being a short circuit to either earth or battery positive .

Whilst we have no set values for what it should be we can still get an idea .. the value will fluctuate in a smooth manner up and down as the car is driven .

With no values from Porsche as to what's correct then you are looking for something that's not right .. ie a constant speed and the value jumping up and down ... a defective sensor in other words .

wjk_glynn · 28 Nov 2019

cardy said:
...Here in Canada...

FYI that if you want feedback from Canadian and/or US based 997.2 owners, take a look at the Rennlist 997 board: https://rennlist.com/forums/997-forum-113/

Lot's of PDK related threads there...

Karl.

cardy · 29 Nov 2019

I've seen the North American stuff, was looking for other ideas
Thanks for the link though

deMort · 30 Nov 2019

I've done a little more digging , best guess is it's the distance sensor as thats all thats listed on the shift rods .. it doesn't appear on the parts list and it does look like a total strip down of the box to replace it ...

Interesting the voltage is 5 volts so on a PWM scope check i would assume the signal will be between 1 and 4 volts and a static signal after it has shifted the rod from end to end .

wjk_glynn · 9 Dec 2019

Related discussion...

https://rennlist.com/forums/997-forum/1172826-guide-to-repairing-a-pdk-transmission.html

Karl.

jayjayaa · 6 Mar 2020

Hello Cardy,

Were you able to solve the problem?
I have a similar problem:
2009 997.2 Targa
Had "WHITE" Transmission Emergency Run eror.
Took it to the workshop, the machine said the one of the coils had failed, the shop replaced the coil and problem fixed.

After 3-4 months, had the same WHITE message. The car was not cold, had driven 50 miles already and the light came up. Issues:
When the light comes up: The transmission does not shift anymore, if I am at 7th, it stays at 7th even if I slow down.
When I stop/restart the car, the message disappears.

I had the message pop up when the car is cold, only after 3-4 miles as well.

The current error code is P1731. Porsche says I should replace the transmission!
I said is there a problem with the transmission? they say no, only the sensor in the pdk is bad. And to replace a whole 25K transmission for a sensor?

Questions: What color was your message, Red or white. From what I read over the internet the Red maybe due to the PDK temp sensor and it gives previous transmission temp warnings.

I would appreciate any comments

deMort · 6 Mar 2020

I am unsure if the distance sensors can be replaced but according to the fault code that is your problem ... the OP never stated if they can be .

The transmission is a lot cheaper than what you have stated on this site .. labour alone would not push it that high.

The fault code does also state it can be the PDK control unit / wiring that's at fault and not the box .

https://www.deroure.com/diagrams.asp?TBL=3022&MAK=3&MDL=27&SMA=0&SMO=0&ST=&SC=0

Images below of the fault code info ..

FYI .. the temp sensor can be replaced but the fault codes indicate its not that .

jayjayaa · 7 Mar 2020

thank you demort

service center said it was shift rod 1 displacement sensor but the code details have only 2 and 4. do you have another page of that error code for shift rod 1

I will tell them to check again for the control unit and the wiring

deMort · 7 Mar 2020

The codes i have are old American ones i found on the internet some years ago and as such are probably outdated and not the total amount of current ones used .

I would guess there is an actual value when looking at data on a tester to see which sensor might be faulty ..

I'm afraid the sad fact remains that the distance sensors are one unit and as such all would be replaced at the same time ... image i posted earlier a few posts upwards .

I'm not aware of any garages in this country that could or do totally strip PDK boxes .

997.2 Targa 4s PDK issues

New member

New member

Monaco

New member

Attachments

New member

Monaco

Monza

New member

Monaco

Attachments

Monza

New member

Monaco

Attachments

New member

Monaco

Similar threads

Porsche Model Range

Porsche 911

Porsche Hypercars

Other Current Porsche Model

Porsche Legacy Models

Forum statistics