Planet-9 Porsche Forum banner
1 - 20 of 22 Posts

·
Registered
Joined
·
17 Posts
Discussion Starter · #1 · (Edited)
So as some know from my high-mileage discussion, I recently purchased a 2013 Boxster S that's in good condition except for an electrical issue impacting 5 systems on the car.

1) Sports + won't activate (regular sports mode is fine)
2) Windscreen won't retract
3) Auto Start/Stop deactivated (battery is new)
4) Dynamic Headlights not functional
5) Park Assist not active / Park Assist menu not selectable

Thoughts are that the problem is from the front body control module which got wet during a recent drain clog that resulted in some water getting under the driver's seat, impacting the control module. Hoping that this controls all of these systems. Part is only ~$400, but not sure if dealer will need to get involved to get it programmed.

Questions are:
1) Does anyone have details on which body control modules control which systems?
2) Does a control module that is ordered need to be programmed by a Porsche dealer, or has anyone had luck with an independent mechanic that can do this?

Thanks for the help as always!
 

·
Registered
Joined
·
264 Posts
So as some know from my high-mileage discussion, I recently purchased a 2013 Boxster S that's in good condition except for an electrical issue impacting 3 systems on the car.

1) Sports + won't activate (regular sports mode is fine)
2) Windscreen won't retract
3) Auto Start/Stop deactivated (battery is new)

Thoughts are that the problem is from the front body control module which got wet during a recent drain clog that resulted in some water getting under the driver's seat, impacting the control module. Hoping that this controls all of these systems. Part is only ~$400, but not sure if dealer will need to get involved to get it programmed.

Questions are:
1) Does anyone have details on which body control modules control which systems?
2) Does a control module that is ordered need to be programmed by a Porsche dealer, or has anyone had luck with an independent mechanic that can do this?

Thanks for the help as always!

There are two body control modules, front and rear. The front BCM lives under the drivers side dashboard, the rear BCM lives under the left seat.

Rear BCM controls loads of things, including a lot of the convertible roof. The CVM is also involved, but it won't work without a good rear BCM. Don't know about the other faults, but everything is so interconnected in the car that I wouldn't be surprised if these were symptoms of a rear BCM failure also.

Yes the rear BCM needs to be coded at the dealership unfortunately. When they do this they will 'join' the front BCM, rear BCM, steering wheel lock, DME (engine computer) and all your keys so the immobiliser is all happy.

Weirdly you can put a rear BCM from another car into it and everything will work fine, but the alarm will want to constantly go off/indicators constantly flash even though you can start the car/lower the roof, etc.
 

·
Registered
Joined
·
264 Posts
Another question, have you checked the fuses?

The rear BCM gets four power feeds. All on the left side, fuses B2,3,4 and fuse C5. C5 is for the convertible roof. B3 is for the alarm, and the other two power a raft of other functions. With a full rear BCM failure you will get a 'system fault' on the instrument cluster screen. You didn't say you were getting this. If you aren't you may have some functionality, which might be due to a fuse failure.
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #4 ·
So I had to edit the original post because when driving home last night I realized the dynamic lighting system is also impacted by this.

I did check a couple of the fuses that seem to be connected to the control module but found nothing blown there.

Let me know if there are any other ideas on this, I plan to call Porsche today to get a cost for BCM replacement and programming.
 

·
Registered
Joined
·
264 Posts
On the face of it I don't think the rear BCM is your problem. Except for the roof not working I'm not convinced the other symptoms have anything to do with the rear BCM. The roof can stop working for a bunch of other reasons.

If I had the problems you are seeing, here is the approach I would take.

Get some diagnostics on the car and see where the failures are originating. If the car can detect the fault it will list it for the control unit that controls it. You are stabbing in the dark without doing this, and will waste money by guessing what the problem is.

If water is in the car you need to dry it out. This is a difficult task. It won't dry by itself easily. I'm still trying to dry the carpets that got wet on this project car. I had them out for about three weeks, thought they were dry, only to install again and get more water come out of the foam. They are out again trying to dry.

To see how wet things are, raise the seats and move forward as far as possible. Stick your fingers in the holes in the carpet and squeeze the foam. Even better, tear open the perforations in the carpet (this is what they are designed for) and have a good look. It should all be dead dry. If not I would suggest removing the carpets to dry them. It's a bit of a task but if you don't and there is any significant water down there you are just waiting for more failures.

Even if you don't remove the carpets, remove the rear BCM. It's under the left seat and sits in a polystyrene foam holder. Disconnect the battery and then remove and disconnect the rear BCM. Remove the four screws on the casing and then remove the plastic casing. The metal side will stay stuck to the circuit board using thermal paste. Leave it like this and let it dry out. I'd stick it in front of a fan for a day.

If you have park assist it will also be under the left seat, and the amplifier will be under the right seat. I'd be opening these to let them dry as well.

This will probably seem daunting, but it's no big deal. If you need guidance I'm more than happy to help. I've made videos of most of this.
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #6 ·
I should have added that the water incident was in November 2021, so about 9 months ago. Has to be dry now, right? :unsure: But great instructions for others.

The PDLS worked today, so I was surprised by that. The convertible top works just fine, it's the retractable windscreen that isn't working along with Sports+ and the Auto Start/Stop. I did call Porsche today and they weren't able to look up which functions were controlled by the body control module. But I can't imagine all these systems are independently messed up. I'm surprised there isn't more information out there on functions controlled by the front vs. the rear BCM or other systems.

Codes that were thrown are below. Mechanic wasn't able to determine what they mean. Anyone have any ideas?
U0159 - No signal / Communication
P000C - Implausible signal
U0418 - Upper limit value exceeded
U0318 - Implausible signal
P1600 - No Signal / Communication
P2026 - Value below lower limit value
 

·
Registered
Joined
·
264 Posts
I should have added that the water incident was in November 2021, so about 9 months ago. Has to be dry now, right? :unsure:
From what I've seen, I would expect it to still be wet. Only takes a few moments to check. It really did surprise me how the foam soaks up the water and holds it for a long time.

I'm a bit confused, when you say 'retractable windscreen' what are you referring to?

Unfortunately those codes don't really help. You really need a Porsche specific diagnostic tool to work out what is going on. It will tell you in plain language what the problem is and what control unit has the error.

To determine what is controlled by each BCM, I would look at the wiring diagram. Link below to workshop manual. Wiring diagrams are at the end.

Workshop Manual
 

·
Administrator
Joined
·
1,827 Posts
Cutting to the chase, since you used numbered questions:

Questions are:
1) Does anyone have details on which body control modules control which systems?
2) Does a control module that is ordered need to be programmed by a Porsche dealer, or has anyone had luck with an independent mechanic that can do this?
#1 - I don't and I can't recall ever seeing one. As was suggested spending some time with a wiring diagram might be useful in determining what controls what.
#2 - If your independent has a PIWIS and is capable using it - chances are he can do what needs doing. Some diagnostics tools can read the info from the old module and then write it to a new module (Foxwell NT530 can do that for several model Porsches). I imagine PIWIS has the same capability. So it depends on what the module is and what tool the mechanic is using.

You never mentioned owning your own diagnostics tool. Shotgunning it (throwing parts at a car until it's fixed) usually will eventually fix it, but it ends up often being an expensive exercise since it's always the last part you install that fixes it, and there may be many parts installed prior to that. A good diagnostics tool offers several capabilities that should make this diagnosis more accurate and hence less costly. A good tool is capable of activating circuits and devices so you can see if they're working or not. A good tool will identify what module controls what simply by what actions you can take on that module. A good tool can read the "state" of a switch, device, sensor, etc - open/closed, reading/not-reading, actual value, etc. Those ALL are clues to an intelligent diagnosis. Your mechanic has something that's giving him OBD-II codes and extended Porsche codes (U codes for instance, or any P#### code P1000 and higher). Those codes can be manufacturer-specific and model-specific (meaning a code like P1234 may mean something different on a different model..)

It seems you're trying to save money by DIY. That's an admirable thing to do, but long-term going about it as you are will end up costing more than if you invested in a diagnostics tool or found a competent mechanic with a PIWIS who knows how to use it.

YMMV, but not a lot I think.. good luck!
 
  • Like
Reactions: spdekold2

·
Registered
Joined
·
17 Posts
Discussion Starter · #9 ·
From what I've seen, I would expect it to still be wet. Only takes a few moments to check. It really did surprise me how the foam soaks up the water and holds it for a long time.

I'm a bit confused, when you say 'retractable windscreen' what are you referring to?
So I checked under the seats, pulled the foam up felt around. All seems dry, which is obviously a good sign.

By retractable windscreen, I mean whatever this button in the middle does in this photo. I assume it's to retract the windscreen/wind deflector, but the button is oddly not referenced in any posts or YouTube videos or anything.

I used the wiring diagram you provided (thank you!) to check a few more fuses, but none of them seem to be bad.
Plant Vehicle Automotive design Personal luxury car Gas
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #10 ·
You never mentioned owning your own diagnostics tool.
Unfortunately I don't have a Porsche specific tool. You're right, it may be worth the invest. However, I did schedule an appointment with Porsche, and they offered to at least read the codes in their system at no charge. I'm still feeling like this is a control module issue of some kind with all of these different systems being out, so I'll probably have to use them anyway to get it programmed. You're right - outside of fuses being bad, these electrical issues tedious and expensive to trial-and-error.

I also found yet another system likely impacted by this today. The park assist. I'm not getting any warnings when parking / near objects, and the menu for park assist is grayed out / not selectable on that menu in the screen. :(
 

·
Registered
Joined
·
264 Posts
By retractable windscreen, I mean whatever this button in the middle does in this photo. I assume it's to retract the windscreen/wind deflector, but the button is oddly not referenced in any posts or YouTube videos or anything.
I'm not sure what is going on there but I've never seen that in a Boxster. That looks like a button console from a 911 cab, which has a retractable windscreen that comes out over the rear seats. These button consoles are interchangeable between the two cars and you just program what each button does. The windscreen between the hoops in the roll bar in a Boxster is only removable by hand.

This might also explain why you are having issues with the start/stop and the sport plus. The buttons might not be programmed. Does your car have the sports chrono option installed (clock in the middle of the dashboard)?

The park assist module is right next to the rear BCM under the left seat. It may have been damaged if there has been water in there. I would be checking if it's there. If it was damaged they may not have replaced it as it's quite expensive for such a small unit. If you open up the carpet under the left seat you will see a styrene holder. The larger control unit that has the silver metal casing is the rear BCM. The smaller one closer to the outside of the car is the park assist module.
 

·
Administrator
Joined
·
1,827 Posts
By retractable windscreen, I mean whatever this button in the middle does in this photo. I assume it's to retract the windscreen/wind deflector, but the button is oddly not referenced in any posts or YouTube videos or anything.

View attachment 283649
Is there a retractable windscreen (I assume behind/between the seats?) I can't recall that being an option. On a 987 it just snaps into retainers on the roll-hoops..

I found via Google image search, one vehicle with the same button - a 2013 911 Cabrio:


Plant Vehicle Automotive design Motor vehicle Grey


And happily - the dealer listing has all the build options, maybe that will give us a clue:

Font Parallel Number Rectangle


Ummm.... nope. I don't see an additional equipment (ie - options) that would cover a retractible windscreen.


I found another image with the same button assembly (2018 Boxster GTS) without the center button - and it had a closeup of the rear windscreen....
Hood Motor vehicle Automotive design Personal luxury car Automotive tire

Note where I pointed the red arrows to - I believe if you push in that square of plastic the top of the screen will release and it will lift out. Does yours have the squares?

And finally - I found the definitive answer - right from Porsche, although it's for the 911, I would guess the function is the same. I'll let you watch it:


Enough Sherlocking tonight... have to go do Facetime with my granddaughter in CA..
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #13 ·
Great research! Thank you! Yes I'm beginning to think that either someone replaced the center console button assembly either to replace a worn one, or while they were trying to fix some of the electrical issues they were having.

I do have the sports chrono package, so while the center windscreen button doesn't work, the Sports+ Button should. It's the only button outside of the windscreen button that doesn't do anything. Even the auto start / stop will illuminate when pressed, but of course the system isn't working. I'll add this thought to my Porsche service appointment and have them check the programming of that whole piece. But, hopefully their system will tell them exactly what's wrong. Just afraid to see the impending bill if it's more than one system that's out 😅

I'll follow-up on the presence of the park assist module. Great ideas from you both!
 

·
Administrator
Joined
·
1,827 Posts
I'll follow-up on the presence of the park assist module. Great ideas from you both!
I would continue to suggest that owning a Porsche specific diagnostics tool will be a productive step. While the dealership might read you the codes for free, they're not going to do diagnostics for free. The diagnostics I'd be looking at would involve activating (using the Porsche specific tool) functions that aren't working via the normal button controls.

You can do this with several tools (the Foxwell NT530 should be able to do most on your car). By trying to activate the actual functions that aren't working you can possibly determine if the problem is the module controlling those functions or the switches that turn the function on/off.

Right now an NT530 is around $170 or so with the Porsche software. Any one of the modules you're questioning, used, will cost at least that. And most of those modules must be coded to the vehicle and the equipment on the vehicle in order to work - something that requires a tool like the NT530 (or Durametric Pro - more $$$) or a visit to a dealer of PIWIS equipped shop.

Pound wise penny foolish comes to mind.. just sayin' - sometimes you have to spend money in order to save money.
 

·
Registered
Joined
·
264 Posts
I do have the sports chrono package, so while the center windscreen button doesn't work, the Sports+ Button should. It's the only button outside of the windscreen button that doesn't do anything. Even the auto start / stop will illuminate when pressed, but of course the system isn't working. I'll add this thought to my Porsche service appointment and have them check the programming of that whole piece. But, hopefully their system will tell them exactly what's wrong. Just afraid to see the impending bill if it's more than one system that's out 😅
To clarify what the car should do, pressing the start/stop button and having it illuminated stops the function from working. The default (light not on) will make the start/stop function work.

Also, the sport plus in a manual car has less functionality than a PDK and I suspect it would be less obvious. A manual owner with a manual transmission can jump in here, but from what I understand you will only get rev matching on down shifts and a tightening of the transmission mounts, which will be very hard to detect.
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #16 ·
Okay, so an update for everyone that has been helping me.

Both control modules under the drivers seat were fried. The rear control module I had installed by Porsche ($1,100, I know, a rip-off, this was before I read the last 2 posts above), and then they quoted $800 to replace the park assist module. I found the park assist module on ebay though for $70 and was able to "program" it using an Autel device my dad had. Really this doesn't seem necessary if you get it from a car with the same features, all it entails is coding the VIN to it.

These issues fixed my park assist system, my auto start / stop, and (so far as I can tell) the PDLS.

I also ordered and self-programmed a new center console button assembly that removed the windscreen feature button that I don't have and ensured that the sports + button was new. This is the only feature that I still can't get to work.

I'm taking it to Porsche tomorrow because my Autel device says the function is not enabled, and Porsche said in my original appointment that this system was fixed when it clearly wasn't, so I'm hoping they can simply enable this for free. I don't see a way to do this with the Autel MX808.
 

·
Registered
2014 Boxster S, Racing Yellow
Joined
·
922 Posts
ensured that the sports + button was new. This is the only feature that I still can't get to work.
Maybe an obvious question, but is your car equipped with the Sport Chrono package? You need that for the Sport+ button to work.
 
  • Helpful
Reactions: deilenberger

·
Registered
Joined
·
17 Posts
Discussion Starter · #18 ·
Okay, so update here. Took the car to Porsche today and they are telling me that while I do have the Sports Chrono Package, I don't have "Sports +." They are telling me that I would need to see option code QR3 or QR5 on my build sheet to have the Sports + button and that it's possible to have the sports chrono package without sports +.

Now, I'm not convinced. I've looked on a few sites that list option codes for 2013 Boxsters, and none of them reference any code starting with QR at all. I do see this on later model years (e.g., current year Macan) but not on 2013 Boxsters. I think they just gave up on activating it, unless someone here knows better??? Any Boxster S owners out there that have the sports + button without that option on their build sheet??
 

·
Registered
2014 Cayman S
Joined
·
226 Posts
Okay, so update here. Took the car to Porsche today and they are telling me that while I do have the Sports Chrono Package, I don't have "Sports +." They are telling me that I would need to see option code QR3 or QR5 on my build sheet to have the Sports + button and that it's possible to have the sports chrono package without sports +.

Now, I'm not convinced. I've looked on a few sites that list option codes for 2013 Boxsters, and none of them reference any code starting with QR at all. I do see this on later model years (e.g., current year Macan) but not on 2013 Boxsters. I think they just gave up on activating it, unless someone here knows better??? Any Boxster S owners out there that have the sports + button without that option on their build sheet??
IIRC there are two sport chrono option codes for the 981 Boxster/ Caymans. The 639 code is for the base and CDR+ radio equipped cars and the 640 code is for the PCM3.1 equipped cars that includes GPS displayed laps and times. Unless a previous owner added the sport plus button you should have the sports chrono package. You should also have the clock/timer on the dash above the radio/ PCM and depending on your steering wheel the sports plus display will light up on the spoke of the Sports Design wheel or on the top of the multi function wheel, when sports plus is activated. I agree that the QR codes are for later models including the Macan.
Jim
 
  • Helpful
Reactions: deilenberger

·
Registered
Joined
·
17 Posts
Discussion Starter · #20 ·
IIRC there are two sport chrono option codes for the 981 Boxster/ Caymans. The 639 code is for the base and CDR+ radio equipped cars and the 640 code is for the PCM3.1 equipped cars that includes GPS displayed laps and times. Unless a previous owner added the sport plus button you should have the sports chrono package. You should also have the clock/timer on the dash above the radio/ PCM and depending on your steering wheel the sports plus display will light up on the spoke of the Sports Design wheel or on the top of the multi function wheel, when sports plus is activated. I agree that the QR codes are for later models including the Macan.
Jim
Thanks for the info. I do have option code 640 on my build sheet (“Sports Chrono Plus Package” as it’s described) and I do have the chrono clock on thedash and everything. I have a Carrera classic wheel so no buttons outside of the sports lights on the dash. But I definitely think this package includes the sports + button.

any reasons this wouldn’t activate besides a dealer programming issue? Button is new, control module under seat is new, regular “sports” mode works. Running out of ideas
 
1 - 20 of 22 Posts
Top