1997 Boxster Won't Start - Immobilizer?

[Glasgow 911SC]

Hello all

I'm hoping someone out there can help an electrical novice with my daily drive.

My car has recently developed a non-start issue. I have the wet carpets problem that so many 986s seem to suffer from. Initially I thought I had fixed the problem with new door liners but it seems my problem may be elsewhere - probably blocked drains.

Either way, my car failed to start last week. The central locking doesn't function, interior light is out and the motor doesn't crank. I removed the alarm unit from beneath the passenger seat (RHD UK car) and there was some slight corrosion on the circuitry. This cleaned up ok after a isopropanol bath. However, the no start issue remained after plugging the unit back in.

At this point it seems like a simple blown alarm unit. However, I unplugged and replugged the unit a few times and eventually the interior lights turned on again. The motor cranked in to life. I used durametric to check the alarm module - P1571 Immobilizer: Open circuit or no signal. The unit responded to various test through durametric but then stopped responding after a few minutes. I turned off the ignition to attempt a restart and nothing - back to square 1. Even when the engine was running, the central locking remained deffective.

Before I spend a probable fortune on a new alarm module, is there anything I can check? It seems weird that the unit functions some of the time after plugging / unplugging multiple times. I've sprayed contact cleaner into the plugs for the alarm module in case it's a connection issue. The Durametric error indicates to me no power is getting to the module - correct? Is there any way to simply remove the immobiliser?

Any help would be appreciated as the thought of a 30 mile round commute on a bus does not appeal!

[Glasgow 911SC]

As a bump, I forgot to mention that the 15Amp fuse in the alarm module is fine and the car is a t-speed manual.

[JFP in PA]

Hello all

I'm hoping someone out there can help an electrical novice with my daily drive.

My car has recently developed a non-start issue. I have the wet carpets problem that so many 986s seem to suffer from. Initially I thought I had fixed the problem with new door liners but it seems my problem may be elsewhere - probably blocked drains.

Either way, my car failed to start last week. The central locking doesn't function, interior light is out and the motor doesn't crank. I removed the alarm unit from beneath the passenger seat (RHD UK car) and there was some slight corrosion on the circuitry. This cleaned up ok after a isopropanol bath. However, the no start issue remained after plugging the unit back in.

At this point it seems like a simple blown alarm unit. However, I unplugged and replugged the unit a few times and eventually the interior lights turned on again. The motor cranked in to life. I used durametric to check the alarm module - P1571 Immobilizer: Open circuit or no signal. The unit responded to various test through durametric but then stopped responding after a few minutes. I turned off the ignition to attempt a restart and nothing - back to square 1. Even when the engine was running, the central locking remained deffective.

Before I spend a probable fortune on a new alarm module, is there anything I can check? It seems weird that the unit functions some of the time after plugging / unplugging multiple times. I've sprayed contact cleaner into the plugs for the alarm module in case it's a connection issue. The Durametric error indicates to me no power is getting to the module - correct? Is there any way to simply remove the immobiliser?

Any help would be appreciated as the thought of a 30 mile round commute on a bus does not appeal!

You are showing all the classic signs of an immobilizer that has fried itself after getting very wet. And, no, there is no realistic way to bypass the immobilizer, it would not be much of a theft deterrent if there was. I think it is time to get the car on a PIWIS unit and evaluate if the unit can be saved or if you are in the market for a new one.

[Glasgow 911SC]

Darn. Thanks JFP. I was hoping someone would chime in with an easy check / fix but deep down I kinda figured it was a lost cause. Local trustworthy specialists are few and far between in my experience so my only option is the dealership. I'm sure they'll see me coming from a mile off, cash register at the ready!

Edited January 27, 2014 by Glasgow 911SC

[JFP in PA]

Darn. Thanks JFP. I was hoping someone would chime in with an easy check / fix but deep down I kinda figured it was a lost cause. Local trustworthy specialists are few and far between in my experience so my only option is the dealership. I'm sure they'll see me coming from a mile off, cash register at the ready!

Problem is that to install a replacement, the unit has to be coded, which requires either a PST II or PIWIS unit, nothing else will work.