Is my rear control module kaput?

[Spumante]

Hi everyone. New member here, but have been playing around with Porsche’s for a while 🙂

 

I recently bought a boxster with a non functional roof. I have been troubleshooting it but it has me stumped. 
 

the previous owner said that the drains had clogged and the rear body computer had to be replaced. He also said the roof had stopped working prior to this, and he didn’t mind as he preferred leaving it closed. Long story short, I can’t really trust what he said. 
 

Until now I checked and confirmed that if I apply 12v in the correct pins in the socket of the rear control module, the relays for the roof both work well. 
and if I apply 12v to the correct pins when I remove the relays, the motor works. So if the body computer sends the signal for the motor to work, it should work. 
 

now, if the right conditions are met (roof latch open, roof ‘not in limit position’, the cluster will say ‘opening convertible top’ or ‘closing convertible top’ if I press the button to open or close the roof. Nothing happens it the roof is latched. 
 

so this tells me that the car recognizes the inputs (micro switches) and it recognizes that it is a boxster convertible (not a cayman or a 911 coupe), and it’s trying to send the signal to the rear body computer. But for some reason this body computer isn’t telling the roof to open. 
 

even when I access the rear body computer with PIWIS, nothing happens when i tell it to open or close the roof. 
 

it’s strange because everything else works (spoiler, lights, trunk lid etc). 
 

in PIWIS I noticed that five fields in the rear module are not working well (corrupted?): Vehicle Type, Country Coding, Inclination sensor, Alarm system, Acoustic alarm output. They all say “?50210” instead of the correct value. This leads me to believe that the rear module is malfunctioning. 
 

however, strangely enough, ‘vehicle type’ is also ‘corrupted’ in the front module and in the gateway. So, what.. are these toast too?

 

would appreciate if anyone has some insight on the above, as a new rear body computer is around 450€ and I don’t wish to spend money for nothing. 
 

thanks!

Edited June 4, 2022 by Spumante

[Loren]

I would not buy a new module without trying to re-program the existing modules. You will need a PST2 or PIWIS tester along with your car's IPAS codes. You can get a copy of your car's IPAS codes from any Porsche dealer/OPC for free - do not let them charge for this. Once you have them you can re-program any module and door/ignition keys with a PST2 or PIWIS tester - so protect them.

[Spumante]

1 hour ago, Loren said:

I would not buy a new module without trying to re-program the existing modules. You will need a PST2 or PIWIS tester along with your car's IPAS codes. You can get a copy of your car's IPAS codes from any Porsche dealer/OPC for free - do not let them charge for this. Once you have them you can re-program any module and door/ignition keys with a PST2 or PIWIS tester - so protect them.

I already tried to recode it using PIWIS. It didn’t change anything. 
I’ve never heard of these IPAS codes. Can you explain further please?

[Loren]

IPAS codes allow you to program or re-program several controllers in the car.

Here is an example with the actual codes hidden.

 

[Spumante]

Thanks. I will try to get them. 
today I found another strange thing. 
 

I was playing around with my PIWIS in simulation mode. 
the same ‘corrupt’ fields appear and i am still unable to change the fields in simulation mode. 

[Spumante]

Update 1: I tried to get the IPAS codes from my local dealer, but they wouldn’t have it. They played dumb like they didn’t know what they are. 
Is there anyone else, maybe someone here working at a dealership, that can get these for me please?

 

Update 2: I went ahead and purchased a new rear control module. I coded it with my PIWIS, and voila.. the top is working again. Now I still have some teething problems (not electronic). But I’ll ask that in a separate thread.
 

Thanks so much.