Alarm control unit removal

[Paul P]

@Arafcan we pin this post please ?

[Indi9xx]

1 hour ago, Paul P said:

@Arafcan we pin this post please ?

If you do want that, please let me re-write it as a proper article rather than me just fingerblasting a rambling reply at 100 words per minute!

 

[pacificjuha]

On 12/7/2020 at 7:37 PM, Richard Hamilton said:

It should read the same on the cigarette lighter.  If it is below about 11.5V off load, it could be your problem.  Try turning the headlights on while you are measuring the voltage.  If it dips significantly, give it a good charge before you try any more detailed troubleshooting.

Right on the money, again @Richard Hamilton 👌

Off load measured 11,4V from the cigarette lighter. I did not get the lights on measure, but sounds like the old battery is the issue. Also, I got the date for the last battery change... Jan 7th 2015 😬 so the current one is close to 6 years old battery.

Time for a battery shopping as the bonnet opens up - hopefully during the upcoming weekend 🤞

 

[pacificjuha]

On 12/7/2020 at 7:37 PM, Richard Hamilton said:

It should read the same on the cigarette lighter.  If it is below about 11.5V off load, it could be your problem.  Try turning the headlights on while you are measuring the voltage.  If it dips significantly, give it a good charge before you try any more detailed troubleshooting.

Ok, today I got to take measures from both, off load voltage (11,4V) and the voltage as I turned the headlamps on (11,0V). This is rather large drop on Voltage, but I do not know if this is normal to so large dip... Any thoughts, is this a normal voltage drop?

Just based on the battery age and the off load voltage, I'll get a new battery as the frunk opens up...😬🤞

[Richard Hamilton]

6 minutes ago, pacificjuha said:

Ok, today I got to take measures from both, off load voltage (11,4V) and the voltage as I turned the headlamps on (11,0V). This is rather large drop on Voltage, but I do not know if this is normal to so large dip... Any thoughts, is this a normal voltage drop?

Just based on the battery age and the off load voltage, I'll get a new battery as the frunk opens up...😬🤞

I would start by giving it a good charge.  A lot depends on the quality of the battery.  I had an original Porsche (Moll) battery on my 987.2 which failed before the car was 3 years old.  I had a Bosch battery on my 911 3.2 Carrera and it was 10 years old when I sold the car and still going strong.  No point in spending money if it just needs a decent charge.

[pacificjuha]

31 minutes ago, Richard Hamilton said:

I would start by giving it a good charge.  A lot depends on the quality of the battery.  I had an original Porsche (Moll) battery on my 987.2 which failed before the car was 3 years old.  I had a Bosch battery on my 911 3.2 Carrera and it was 10 years old when I sold the car and still going strong.  No point in spending money if it just needs a decent charge.

The currenbt battery is 'Bosch S4010 80Ah/740A' and it was installed on Jan 7th 2015. Previous owner did not drive the car much on last five years adn it was kept in warm garage thru the winters.

What you mention is for sure worth a try, but while I tinker with the charging, I'll this time leave the frunk latch out from the frunk lid or route the frunk opening cable so it is visible and easy to pull if the same happens again during this winter as the car is stationary untill spring...😇

[Boxob]

@Indi9xx

What a tremendous post (and not the first). It deserves a place in the "How to" forum.

So "waterproof" boxes for the ACU are a no no. Relocating the ACU would be a good idea. I'm surprised there isn't an aftermarket solution, for example, a plug and play loom extension. There's plenty of broken cars from which to scavenge the relevant lengths of wiring loom and connectors. 

Any other ideas. If a client is spending money on a replacement ACU then they probably will want to protect it! Cleaning the drain holes is a first but not foolproof. My local OPC had a flooded Boxster in. The OPC found a pair of sunglasses had blocked the drainage hole. Owner had put his sunglasses on the roof and then lowered the roof. He didn't think to look in the foam catch tray and wrote them off as lost.

[PaulQ]

28 minutes ago, Boxob said:

@Indi9xx

So "waterproof" boxes for the ACU are a no no. 

Ive toyed with the idea, but as stated unless you can guarantee that the cable entry/exits are 100% waterproof, then it could potentially do more harm then good. 

Not impossible to do though by any means 

I think a good compromise would be a conformal coating for the pcb, as even if you don't have any water ingress issues, this would protect the pcb from corrosion and extend the service life. 

[Indi9xx]

On 12/9/2020 at 7:59 PM, Boxob said:

So "waterproof" boxes for the ACU are a no no. Relocating the ACU would be a good idea. I'm surprised there isn't an aftermarket solution, for example, a plug and play loom extension. There's plenty of broken cars from which to scavenge the relevant lengths of wiring loom and connectors. 

Getting the car harness side connectors for this is not a problem.

I did try to source the "ACU" side connectors and came very close to a connector for one of the two connectors, but drew a blank with the other.

I did not get as far as thinking through the other pro's and con's, but was concerned about making sure where an extension loom plugs into the car harness that it neither low enough to end up under water itself, but also not so high as to potentially catch on the underside of the seat, but that could probably be defeated.

But hitting a bit of a wall in the source of the connectors was probably what killed that train of thought for me.

The other thing I had not given much thought towards, but was obviously something to overcome, was where to relocate the ACU to.

Thatchum (insurance) regulations state that any thatchum approved alarm either needs to be in a metal box that requires tools to open, or the alarm needs to be located somewhere that makes it difficult to tamper with unless you have tools to remove other equipment in the way.

This is something we have to be mindful of when installing aftermarket alarm systems into customers cars, you would not believe how many alarms we remove which breach thatchum regulations on so many levels, but nobody would be any the wiser until their car was stolen and recovered, causing the insurance to then say it was uninsured.

We lacquer the boards if the customer wants some extra protection, but even that could be seen as invalidating the Porsche warranty. But the problem with lacquering it does nothing to waterproof the relays, which are one of the first things to suffer.

The problem with potting the boards in resin is that it still leaves the connectors, both on the ACU and the wiring harness completely non waterproofed, which then can blow the board due to the wires shorting outside of the ACU, which can be as bad as it shorting internally.

We have an auxiliary drain kit we offer customers, which includes strainers to help stop anything larger than a couple of mm across getting into the drains, while also increasing their surface area by about 25 times that of the original drain holes, as well as additional drain points for the rear floor pans, the second item requiring holes being drilled in the floor with an included 10mm drill bit, and drains installed into them which allow water out, but stop water spray from the roads getting in. Which we have provided for a about 4 years now, with no news of a car with them getting flooded. I think Porsche should have done something like this years ago.

For 987 owners, I have a bit of a funny story that I was told "off the record" by a Porsche engineer at the Stuttgart technical support office.

Porsche were aware that there was problems with Boxster 986's flooding due to blocked drains very early on in production. So with the 987 the engineer in charge of security decided to move the alarm control unit to another location.. A little while after this another engineer was looking for somewhere to mount the all new "Rear Body Control Unit", and noticed a really convenient location under the drivers seat (passenger seat in RHD cars).... Which is why flooded 987's no longer kill ACU's but instead kill Rear Body Control units.

 

 

[iborguk]

2 minutes ago, Indi9xx said:

Getting the car harness side connectors for this is not a problem.

I did try to source the "ACU" side connectors and came very close to a connector for one of the two connectors, but drew a blank with the other.

I did not get as far as thinking through the other pro's and con's, but was concerned about making sure where an extension loom plugs into the car harness that it neither low enough to end up under water itself, but also not so high as to potentially catch on the underside of the seat, but that could probably be defeated.

But hitting a bit of a wall in the source of the connectors was probably what killed that train of thought for me.

The other thing I had not given much thought towards, but was obviously something to overcome, was where to relocate the ACU to.

Thatchum (insurance) regulations state that any thatchum approved alarm either needs to be in a metal box that requires tools to open, or the alarm needs to be located somewhere that makes it difficult to tamper with unless you have tools to remove other equipment in the way.

This is something we have to be mindful of when installing aftermarket alarm systems into customers cars, you would not believe how many alarms we remove which breach thatchum regulations on so many levels, but nobody would be any the wiser until their car was stolen and recovered, causing the insurance to then say it was uninsured.

We lacquer the boards if the customer wants some extra protection, but even that could be seen as invalidating the Porsche warranty. But the problem with lacquering it does nothing to waterproof the relays, which are one of the first things to suffer.

The problem with potting the boards in resin is that it still leaves the connectors, both on the ACU and the wiring harness completely non waterproofed, which then can blow the board due to the wires shorting outside of the ACU, which can be as bad as it shorting internally.

We have an auxiliary drain kit we offer customers, which includes strainers to help stop anything larger than a couple of mm across getting into the drains, while also increasing their surface area by about 25 times that of the original drain holes, as well as additional drain points for the rear floor pans, the second item requiring holes being drilled in the floor with an included 10mm drill bit, and drains installed into them which allow water out, but stop water spray from the roads getting in. Which we have provided for a about 4 years now, with no news of a car with them getting flooded. I think Porsche should have done something like this years ago.

For 987 owners, I have a bit of a funny story that I was told "off the record" by a Porsche engineer at the Stuttgart technical support office.

Porsche were aware that there was problems with Boxster 986's flooding due to blocked drains very early on in production. So with the 987 the engineer in charge of security decided to move the alarm control unit to another location.. A little while after this another engineer was looking for somewhere to mount the all new "Rear Body Control Unit", and noticed a really convenient location under the drivers seat (passenger seat in RHD cars).... Which is why flooded 987's no longer kill ACU's but instead kill Rear Body Control units.

 

 

Another great post and you couldn’t make it up re the Rear Body Control Unit, easy to see how that would happen!

[Boxob]

8 minutes ago, Indi9xx said:

Getting the car harness side connectors for this is not a problem.

I did try to source the "ACU" side connectors and came very close to a connector for one of the two connectors, but drew a blank with the other.

I did not get as far as thinking through the other pro's and con's, but was concerned about making sure where an extension loom plugs into the car harness that it neither low enough to end up under water itself, but also not so high as to potentially catch on the underside of the seat, but that could probably be defeated.

But hitting a bit of a wall in the source of the connectors was probably what killed that train of thought for me.

 

I wonder whether the ACU side connectors could be sourced by cannibilsing defunct ACUs? Seems like there'd be a reasonable supply!

Where did Porsche relocate the 987s ACU to? If it's an acceptable location on a 987 would it work on a 986?

[Menoporsche]

Rear bulkhead IIRC.

[Indi9xx]

1 minute ago, Boxob said:

I wonder whether the ACU side connectors could be sourced by cannibilsing defunct ACUs? Seems like there'd be a reasonable supply!

Where did Porsche relocate the 987s ACU to? If it's an acceptable location on a 987 would it work on a 986?

It would have to be a long extension loom to rehouse the alarm under the dashboard to be like the 987.

If someone wanted to be absolutely sure about keeping the alarm system dry, I would probably go for one of the boxes, install it with the alarm not in it's case, just the PCB, and then fill the aftermarket alarm box with potting resin. connectors and all. About a litre or a litre and a half should do it.

[Indi9xx]

1 minute ago, Menoporsche said:

Rear bulkhead IIRC.

You may well be right... Since the 987 came out I have never had to go find one! lol

Although I do remember there being a security module near the ignition switch area under the dashboard, I seem to remember having to fix a bad connector on one which would not crank the starter motor... But that could have been another model such as the 981 or my ageing brain playing tricks on me.

One the other hand, drenched rear body control units and amplifiers in 987's and 981's are extremely common in the workshop, including the 981's park assist. I know all too well where they all are.. We usually see about one a week come in with one of those drenched.

The 981's are also a nightmare to properly clear the drains, sludge builds up at the bottom of the rubber drain collector (which can then freeze and split the seal), and to clear it you need to take the entire side skirt assemblies off. Just delivered one like this back to the customer today which had split the seal.

997 Cabriolets are also a bit of a pain to clear the drains, having to remove the rear wheel arch liners to access the sludge filled drain ports.

[Boxob]

@Indi9xx

Another thought I had was to raise the ACU, hopefully, above the water line.  My understandinging is the ACU bolts to the floor. If longer bolts and spacers were used the ACU could be raised say 25mm. It depends on there being some slack in the wiring loom but as I've not actually seen the ACU I've no idea.  Do you know whether raising the ACU is feasible?

[Indi9xx]

15 minutes ago, Boxob said:

@Indi9xx

Another thought I had was to raise the ACU, hopefully, above the water line.  My understandinging is the ACU bolts to the floor. If longer bolts and spacers were used the ACU could be raised say 25mm. It depends on there being some slack in the wiring loom but as I've not actually seen the ACU I've no idea.  Do you know whether raising the ACU is feasible?

This is doable, on the later models the tilt sensor hooks onto the top of the ACU, so there should be space for the ACU to lift up 25mm and for the later models a bracket to put the tilt sensor next to it rather than on top of it.

 

[pacificjuha]

On 12/9/2020 at 9:03 PM, Richard Hamilton said:

I would start by giving it a good charge.  A lot depends on the quality of the battery.  I had an original Porsche (Moll) battery on my 987.2 which failed before the car was 3 years old.  I had a Bosch battery on my 911 3.2 Carrera and it was 10 years old when I sold the car and still going strong.  No point in spending money if it just needs a decent charge.

It is getting a bit more wierd now... I opened the frunk successfully by the cable in the fenderwell. Removed the battery and measured the battery's voltage as it was out from the car -> it measures now 12V...

Thru the cigarette lighter it showed 11,4V without a load. Could there be something eating up the power and then alarm not being happy about it? This has not happened to me before as I have re-connected the battery to the Boxster. There has not been issues of low power on the battery at all nor charging issues.

Is there something else that I should take when re-connecting the battery and the ACU than the following:

1. Connect the ACU normally

2. place the key ignition and turn it to 1st position

3. connect the battery's positive lead

4. connect the battery's negative lead

Then what??? Should I try to start the car or do somethign else next (I still have the frunk lock latch not attached to make sure that I can open the frunk if something goes crazy again...)

All help and ideas would be most appreciated as I try not cause issues with my neighbors due to the alarm going off...

[Richard Hamilton]

25 minutes ago, pacificjuha said:

It is getting a bit more wierd now... I opened the frunk successfully by the cable in the fenderwell. Removed the battery and measured the battery's voltage as it was out from the car -> it measures now 12V...

Thru the cigarette lighter it showed 11,4V without a load. Could there be something eating up the power and then alarm not being happy about it? This has not happened to me before as I have re-connected the battery to the Boxster. There has not been issues of low power on the battery at all nor charging issues.

Is there something else that I should take when re-connecting the battery and the ACU than the following:

1. Connect the ACU normally

2. place the key ignition and turn it to 1st position

3. connect the battery's positive lead

4. connect the battery's negative lead

Then what??? Should I try to start the car or do somethign else next (I still have the frunk lock latch not attached to make sure that I can open the frunk if something goes crazy again...)

All help and ideas would be most appreciated as I try not cause issues with my neighbors due to the alarm going off...

Not too surprising.  With the battery connected there will be some drain from connected devices and modules, even with the ignition off.  Removing the battery disconnects it from everything.  Like I said, I would give it a full charge, and then try again - using the steps you show, and try to start the car.

I'm guessing you are in the US, so probably don't have the alarm siren?  If you do have it, I would disconnect it, and the alarm horn (on the other side of the battery, before you reconnect everything else.  That way, if it triggers the alarm, only the indicators will flash.

[pacificjuha]

1 hour ago, Richard Hamilton said:

Not too surprising.  With the battery connected there will be some drain from connected devices and modules, even with the ignition off.  Removing the battery disconnects it from everything.  Like I said, I would give it a full charge, and then try again - using the steps you show, and try to start the car.

I'm guessing you are in the US, so probably don't have the alarm siren?  If you do have it, I would disconnect it, and the alarm horn (on the other side of the battery, before you reconnect everything else.  That way, if it triggers the alarm, only the indicators will flash.

Thanks @Richard Hamilton. I'm in Finland, but the car is US spec 2001 with 2.7 engine + manual transmission. It does not have the separate siren, but does have the alarm horn next to the battery - good advice thank you, I'll disconnect the alarm horn before  reconnecting the ACU and battery.

[Indi9xx]

On 12/13/2020 at 10:50 AM, pacificjuha said:

It is getting a bit more wierd now... I opened the frunk successfully by the cable in the fenderwell. Removed the battery and measured the battery's voltage as it was out from the car -> it measures now 12V...

Thru the cigarette lighter it showed 11,4V without a load. Could there be something eating up the power and then alarm not being happy about it? This has not happened to me before as I have re-connected the battery to the Boxster. There has not been issues of low power on the battery at all nor charging issues.

Is there something else that I should take when re-connecting the battery and the ACU than the following:

1. Connect the ACU normally

2. place the key ignition and turn it to 1st position

3. connect the battery's positive lead

4. connect the battery's negative lead

Then what??? Should I try to start the car or do somethign else next (I still have the frunk lock latch not attached to make sure that I can open the frunk if something goes crazy again...)

All help and ideas would be most appreciated as I try not cause issues with my neighbors due to the alarm going off...

 

If you are getting different voltages in different locations around the car, there are a few things it could be.

If for example you find that you are getting lower voltages on items which are only powered with the ignition turned on, compared to the permanent lives in the car, I would potentially point the finger of blame at the ignition switch.

If however it seems like one circuit, or a few circuits are getting odd voltages, I would look at the wiring diagrams and see if there is a connection between the circuits and particular internal fuses in the power distribution unit (not the fuse box, but the box the positive terminal connects to. As this goes through the bulkhead, and the bulkhead can flood (often killing brake servos), we have seen several 986's where the terminals that the internal fuses screw down with have corroded, causing higher resistance and lower voltages to effected circuits.

On the 987's the unit seems better sealed against flooding, but they instead also updated the design of how the positive battery cable connects to it, as a quick release fitting, rather than a nut on a stud, where the pin/stud corrodes, as well as the quick release fitting, making for a poor contact. For these we have a conversion kit to convert the quick release stud back into a threaded stud and nut, using a stainless steel CNC turned stud to avoid any chance of corroding the stud. (New power distribution units are extremely expensive for what they are.

I think you might need to do some wiring diagram studying to drill down on the voltage differences.

With the process of connecting up the ACU, then the battery, with the key in the ignition and on the "ignition on" position, the alarm should not sound, as the ACU will read the transponder as part of its "power-on" bootup process, see the right transponder, and then decide everything is fine and no need for concern.

 

[pacificjuha]

1 hour ago, Indi9xx said:

 

If you are getting different voltages in different locations around the car, there are a few things it could be.

If for example you find that you are getting lower voltages on items which are only powered with the ignition turned on, compared to the permanent lives in the car, I would potentially point the finger of blame at the ignition switch.

If however it seems like one circuit, or a few circuits are getting odd voltages, I would look at the wiring diagrams and see if there is a connection between the circuits and particular internal fuses in the power distribution unit (not the fuse box, but the box the positive terminal connects to. As this goes through the bulkhead, and the bulkhead can flood (often killing brake servos), we have seen several 986's where the terminals that the internal fuses screw down with have corroded, causing higher resistance and lower voltages to effected circuits.

On the 987's the unit seems better sealed against flooding, but they instead also updated the design of how the positive battery cable connects to it, as a quick release fitting, rather than a nut on a stud, where the pin/stud corrodes, as well as the quick release fitting, making for a poor contact. For these we have a conversion kit to convert the quick release stud back into a threaded stud and nut, using a stainless steel CNC turned stud to avoid any chance of corroding the stud. (New power distribution units are extremely expensive for what they are.

I think you might need to do some wiring diagram studying to drill down on the voltage differences.

With the process of connecting up the ACU, then the battery, with the key in the ignition and on the "ignition on" position, the alarm should not sound, as the ACU will read the transponder as part of its "power-on" bootup process, see the right transponder, and then decide everything is fine and no need for concern.

 

Thanks Jon,

I changed the ignition switch to a new one during last summer, so it should be fine. 

Sounds like I'll need some wireing study to do - not my favorite task to try to sort out the electrical issues...

Yesterday early afternoon I placed the battery to the charger is a room temperature and it took approximately 22 hours to get the 'smart charger' to tell me that the battery is fully charged. Plenty of power had disappeared somewhere regardless that, thru the summer there was never any issues with power.

[Indi9xx]

20 hours ago, pacificjuha said:

Thanks Jon,

I changed the ignition switch to a new one during last summer, so it should be fine. 

Sounds like I'll need some wireing study to do - not my favorite task to try to sort out the electrical issues...

Yesterday early afternoon I placed the battery to the charger is a room temperature and it took approximately 22 hours to get the 'smart charger' to tell me that the battery is fully charged. Plenty of power had disappeared somewhere regardless that, thru the summer there was never any issues with power.

One of the interesting things with car batteries is that usually they will only ever be 80% charged by driving the car.

A good battery conditioner can take one up closer to 100% charged (as close as a lossy system like a lead acid battery can get) but likewise a good battery conditioner will often take twice as long to charge a battery from 80% to near 100%, as it did to charge from a flat battery to 80%

Nothing to do with your problem, but I often recommend people with cars not used every day to go for an AGM battery, they can accept a charge faster than a traditional battery, they output more amps at the same level of discharge, and most importantly are more resilient to being discharged and fast charged, which is why they work well in "Start stop" enabled modern cars, and why they are so good for classic or weekend cars.

 

[pacificjuha]

Today was the day to re-install the battery.... and it worked out!!! but not without issues first

First I un-plugged the alarm horn, then installed the ACU (in order of: antenna, blue plug, black plug), connected battery's positive lead, installed key and turned it to 1st position and connecte the battery's negative lead --> alarm started flashign lights, but luckily no noice.

Disconnected the battery, key out and started from the kay installation again --> still lights (alarm) going off.

Then removed the ACU ans checked to confirm again that all connection pins are fine (yes they are) re-installed all as in the first time today. Same result...

Again, took of the battery negative lead and ACU. Few slow inhales of fresgh air and...

Now a bit differently: Connected the ACU in this order: Black pug, blue plug, antenna. Installed the key and turned it to 1st position, connected the battery's negative lead AND all is well, no flashing lights

Started the car, letting it warm up by varying the rpm's and tested both bonnets opening. all works as did before I removed the ACU couple of weeks ago.

The mystery of key fobs not discussing with the ACU still remains...

[Knobgoblin]

I've just had this issue again after my alarm unit got flooded a few weeks back. During some heavy rain I was away at work in London when my other half rang to tell me the alarm was going off. Got the neighbour to unlock the car and disconnect the battery to shut it up.

On my return home I felt under the pas seat and again the unit was in water. So seat out and some side trim removed to pull the carpet up and I find a small river and the carpet sodden, its gone into the alarm module cavity and into the front ahead of the seat.  My drain holes are clear and although I cant find any rips in the drip tray im at a loss how its getting in without soaking the bulkhead carpet nor leaving any damp around where the seatbelt reel is behind that corner trim. Only seems to occur during really heavy rain also.

I removed the unit which I had put back in last time inside a plastic bag and tie wrapped the connector ends, the water hadn't really got in as much as last time despite far more water in the car so there was only light moisture inside on the board. I again used contact cleaner on the board and left the box and pcb in the airing cupboard to dry whilst I sorted the mess left in the car.

Whilst refitting I figured if I could get the ACU box under the seat it would be high enough not to be immersed if it happend again. I managed to get the box wedged under the seat frame and got it connected up, but each time I bolted the seat down the black connector would pop out. I resorted to using a plastic bag and tie wraps again but extending the bag as far as I could over the harness.

I refitted the interior, key in ignition and connected up the battery. Again to my surprise, considering this is the second time its happened to me, the car started ok, all my interior lights worked and so does my key fob, it locks and unlocks perfectly. Considering the fob didnt work at all when I got the car, and the previous owner said it hadn't worked in the 8 years he owned it, I somehow got it to spring to life with a new battery and later some new switches soldered onto the fobs board, im quite impressed anything works! 

I bought a half cover to see if that will stop any further leaks over winter until better weather when I can strip the interior and find out what the hell is going on.  Had her out tonite to get some heat through the interior to aid drying out, i also bought 2 large bag things from halfords to soak up moisture and they already seem to be making a difference. I can see a hole drilled in the floor would stop it for good if I cant find how water is getting in, with some sort of rubber grommet perhaps. My door cards are dry also. 

 

[CRC]

I've got a hlf cover on mine, and I've pulled it across a bit to cover all the gaps on the near side of the car, but somehow, water still finds it's way into the well behind the passengers seat. Even if the drip membrane on that side still has a few holes in it still, it's hard to work out how it can let water in when the half cover isn't letting any down onto it.

If you do find the problem, please let me know .......