Need Immobiliser advice - 986 Forum - The Community for Porsche Boxster & Cayman Owners

imari · 08-05-2016, 02:17 PM

I have a 01 Boxster that won't start. I am almost 100% sure that it's the immobiliser but I'm not sure of the next steps.

The alarm went off, I unplugged the battery to stop it, reconnected it and everything works BUT it won't start. The carpet is soaked so I removed the seat to find a good amount of water underneath. I removed the immobiliser to have dried the box and circuit board. I do see some corrosion and there was some condensation and water inside. I'm not sure if it will still work or not. I plan to let it completely dry and then reinstall to test (btw do I have to reconnect the seat wiring of just the immobiliser unit to test?).

Has anyone had this issue and successfully repaired it? Do I need to go online and buy another circuit board if this doesn't work??? and if I do should I get another key, transponder, ignition, etc to go with it??? Does it have to be reprogrammed by a dealer???

Any advice would be greatly appreciated.

911monty · 08-05-2016, 02:25 PM

Replied in the other thread but found the link to a company that can also repair the board and sell you a Waterproof case to prevent this from happening again.

Porsche Boxster & 996 Immobilizer Waterproof Case Enclosure

edit: found the other post recommending ISO Alcohol.

So the long process is over. The issues was the Immobilizer. I was saved when I read this post from Pedro and i suggest anyone who runs into an issue with their's, try this first before replacing:
"Try removing the driver's seat and then the CLU.

Disconnect it from its harness, remove it from the car and open the case.

Remove the printed circuit board and dunk it in a shallow recipient and cover it with isopropyl alcohol.

Shake it well so the alcohol penetrates all the spaces, in particular between the chips and connections.

Then, let it dry. You can accelerate the drying by using a hair dryer in the cool mode.

Dry out the inside of the case if it had humidity and put everything back together.

If it was water causing the problem, it should now work fine.

We have saved many CLUs this way."

Thanks everyone for your help!

imari · 08-05-2016, 06:26 PM

Quote:

Originally Posted by 911monty

Replied in the other thread but found the link to a company that can also repair the board and sell you a Waterproof case to prevent this from happening again.

Porsche Boxster & 996 Immobilizer Waterproof Case Enclosure

edit: found the other post recommending ISO Alcohol.

So the long process is over. The issues was the Immobilizer. I was saved when I read this post from Pedro and i suggest anyone who runs into an issue with their's, try this first before replacing:
"Try removing the driver's seat and then the CLU.

Disconnect it from its harness, remove it from the car and open the case.

Remove the printed circuit board and dunk it in a shallow recipient and cover it with isopropyl alcohol.

Shake it well so the alcohol penetrates all the spaces, in particular between the chips and connections.

Then, let it dry. You can accelerate the drying by using a hair dryer in the cool mode.

Dry out the inside of the case if it had humidity and put everything back together.

If it was water causing the problem, it should now work fine.

We have saved many CLUs this way."

Thanks everyone for your help!

Good news....I dried the circuit board and enclosure, gently cleaned the board with a toothbrush, reconnected everything....and just like magic, she started right up!!! Problem solved. I do plan on finding the source of the leak and getting the waterproof case. I am relieved that I didn't have to drop another stack of cash to figure this out. The ONLY problem so far is that my airbag light is on and my interior dome light stopped working...smh. Go figure. I'll work on that part tomorrow

Gelbster · 08-05-2016, 07:48 PM

The cause of the leak may be blocked drains. Clear with coat-hanger wire and compressed air.Search for details.
IMHO it is all a waste of time unless you drill a drain hole in the floor at the lowest point. Sooner or later there will be another flood and you'll have the same problem. A couple of ziplock backs around the immobilizer case may work perfectly. But if the water can't drain away it will create a puddle there.

kiyakubuke · 08-09-2016, 05:30 PM

parking lot I was in got flooded in a sudden, intense thunderstorm on Sat. about an inch of water under the drivers seat. I did similar, but put the circuit board in a box of dry rice overnight. put it all back together today and it works except that the key fob won't open the trunk or hood, or arm/disarm the alarm. the red receiver light on the dash lights up when I press the buttons, but no reaction from the car. also, the central locking doesn't work, and the hood/trunk releases only work when the ignition is on. otherwise it seems to start and run with no issues and it isn't doing the crazy hood/trunk unlocking randomly, alarm going off etc.. that it was doing when it was wet. just filed a claim with insurance to see if they will pay for it getting fixed.

btw, your airbag light may be on because you had the seat unplug when the battery was connected (happened to me once). it take a durametric tool to reset it. my shop did it for free, but the dealer will probably charge you.

imari · 08-09-2016, 06:32 PM

Quote:

Originally Posted by kiyakubuke

parking lot I was in got flooded in a sudden, intense thunderstorm on Sat. about an inch of water under the drivers seat. I did similar, but put the circuit board in a box of dry rice overnight. put it all back together today and it works except that the key fob won't open the trunk or hood, or arm/disarm the alarm. the red receiver light on the dash lights up when I press the buttons, but no reaction from the car. also, the central locking doesn't work, and the hood/trunk releases only work when the ignition is on. otherwise it seems to start and run with no issues and it isn't doing the crazy hood/trunk unlocking randomly, alarm going off etc.. that it was doing when it was wet. just filed a claim with insurance to see if they will pay for it getting fixed.

btw, your airbag light may be on because you had the seat unplug when the battery was connected (happened to me once). it take a durametric tool to reset it. my shop did it for free, but the dealer will probably charge you.

I wish that I had better news but I don't...after I THOUGHT I had everything fixed (except the airbag light staying on), it rained again yesterday and I got more water on the floorboard (including the immobilizer unit). Needless to say, now the car won't start at all. I tried to dry the board like last time but it didn't help. I was going to take the battery loose to see if I could "reset" the system but like yours the trunk and hood won't open. With a fully charged new battery, I have no idea how to get the hood to open????? I also noticed that the windows won't work (up or down). This is more complex than what I just went through with the first time the box got wet....smh. I have really tried but I am convinced that I need to get it running and then get to running.

kiyakubuke · 08-09-2016, 06:42 PM

Quote:

Originally Posted by imari

I wish that I had better news but I don't...after I THOUGHT I had everything fixed (except the airbag light staying on), it rained again yesterday and I got more water on the floorboard (including the immobilizer unit). Needless to say, now the car won't start at all. I tried to dry the board like last time but it didn't help. I was going to take the battery loose to see if I could "reset" the system but like yours the trunk and hood won't open. With a fully charged new battery, I have no idea how to get the hood to open????? I also noticed that the windows won't work (up or down). This is more complex than what I just went through with the first time the box got wet....smh. I have really tried but I am convinced that I need to get it running and then get to running.

same with me. however my hood and trunk releases on the door sill work if the ignition is on. central locking and windows do not. pretty sure it is beyond my ability to repair at this point. we will see what insurance says.

curious though, is the immobilizer unit (under seat) tied to the ecu (in the trunk)? i.e. you have to replace them as one. the reason I ask it that searching eBay, it seems you can't get just the one, all listing are in a pair.

kiyakubuke · 08-19-2016, 07:05 AM

filed an insurance claim for this, had to take it to the dealer for an diagnostics and estimate. the said it was the "theft control unit" aka immobilizer unit (big surprise). estimate was $2000. that was for a new unit and 2 keys. I can buy a used unit on eBay for around $600 that comes with 2 keys already paired. might use the rest for some new shoes