3rd Party Keyless Entry DIY (Why Not?)

[sniktaw]

Hi Guys,

fitted one of these today on an 04 MY using the BN/WH & BN/RD wires under the seat at the immobiliser and everything works a treat. However, 5 minutes after locking the car it cannot be opened using the new remote (as described by others here). The unit operates but the car does not respond. Anyone resolved this issue?

TIA, Darren

[EuropaDrive]

Originally Posted by sniktaw

Hi Guys,

fitted one of these today on an 04 MY using the BN/WH & BN/RD wires under the seat at the immobiliser and everything works a treat. However, 5 minutes after locking the car it cannot be opened using the new remote (as described by others here). The unit operates but the car does not respond. Anyone resolved this issue?

TIA, Darren

I suspect that you must have tapped into a switched 12-volt wire to power your unit, that turns off after a few minutes, such as the trunk light. Best would be to put a voltmeter on the +12V wire, lock the doors and see if the voltage drops after 5 minutes...

[sniktaw]

Originally Posted by EuropaDrive

I suspect that you must have tapped into a switched 12-volt wire to power your unit, that turns off after a few minutes, such as the trunk light. Best would be to put a voltmeter on the +12V wire, lock the doors and see if the voltage drops after 5 minutes...

Sorry should have started originally that I had same thought and thus wired direct to +12V at battery to double check - sadly, same outcome ;o(

[scrappyloz]

Hi guys i joined this forum so i could let you you know how to fix your issue of it no longer working after 15 seconds.

My car is a 2001 Porsche 996 911 3.4 but this will also work for the 986 boxster. Please note my car RHD so my ecu is under my the passenger seat (left hand side of the car) Im unsure if its also on the same side on a US car

The ecu has two main connecter plugs. One plug has inputs into the ECU and the other plug is outputs. The problem you guys are having is that you have wired into the ecu input wires not output.

I sorted my issue a couple of months ago but it has taken my account a while to activate so i will do my best to remember.




Right first thing you need to do is read the instructions of your aftermarket alarm. You will be wiring it as Single point locking NOT negative ground locking.
This means you will be wiring it as if you are wiring it to an actuator that will reverse the polarity of the wires when you press lock or unlock.


The wires you are looking for go into the rearmost plug of your ecu.

If you look at a porsche wiring diagram for your door lock, you are looking for the two wires that run the central locking motor in the lock. Mine were terminal A1 (Blue/Yellow) and A2 (Green/Red). Both front door locks are linked to the same two wires where they go into the ecu.

If you look at the rearmost plug on your ecu you will see these two wires (Green/Red and Blue/Yellow). Please note: there are another pair of wires that are the same color but with a colour band round them It is NOT the banded wires.

You need to cut the the two wires and then join them to your 3rd party alarm. You will be using the loom end of the wires you have cut NOT the end where it goes into the ecu.

I have done my best to explain this. Let me know if i can be any more help

[MaddogsMotorSports]

Scrappyloz can you post some pics please, I have a 2003 base boxster that I will try and rewire this spring. Thanks

[scrappyloz]

Originally Posted by MaddogsMotorSports

Scrappyloz can you post some pics please, I have a 2003 base boxster that I will try and rewire this spring. Thanks

Sorry i have sold the car to a friend of mine but if you get stuck let me know

[MaddogsMotorSports]

so has anyone tried this yet?

Originally Posted by scrappyloz

Hi guys i joined this forum so i could let you you know how to fix your issue of it no longer working after 15 seconds.

My car is a 2001 Porsche 996 911 3.4 but this will also work for the 986 boxster. Please note my car RHD so my ecu is under my the passenger seat (left hand side of the car) Im unsure if its also on the same side on a US car

The ecu has two main connecter plugs. One plug has inputs into the ECU and the other plug is outputs. The problem you guys are having is that you have wired into the ecu input wires not output.

I sorted my issue a couple of months ago but it has taken my account a while to activate so i will do my best to remember.




Right first thing you need to do is read the instructions of your aftermarket alarm. You will be wiring it as Single point locking NOT negative ground locking.
This means you will be wiring it as if you are wiring it to an actuator that will reverse the polarity of the wires when you press lock or unlock.


The wires you are looking for go into the rearmost plug of your ecu.

If you look at a porsche wiring diagram for your door lock, you are looking for the two wires that run the central locking motor in the lock. Mine were terminal A1 (Blue/Yellow) and A2 (Green/Red). Both front door locks are linked to the same two wires where they go into the ecu.

If you look at the rearmost plug on your ecu you will see these two wires (Green/Red and Blue/Yellow). Please note: there are another pair of wires that are the same color but with a colour band round them It is NOT the banded wires.

You need to cut the the two wires and then join them to your 3rd party alarm. You will be using the loom end of the wires you have cut NOT the end where it goes into the ecu.

I have done my best to explain this. Let me know if i can be any more help

[supersaiyan93]

I hate to necromance this old post, but it's the best one I found on the topic.

I'd like to add another point of data to it and share some notes from my install.

I have the M535 CU in my 2001 Boxster S, but my car wasn't optioned with the factory alarm system.
When I bought my car, it came with two keys, one that was just the back half of the key with the immobilizer pill, and the other one a complete key but with a non-functioning transmitter. Needless to say, every attempt at fixing that transmitter or re-establishing communication with the car failed. I punted and went with one of these $15 aftermarket systems.

I followed the instructions on page one of this thread, and I'm happy to report that on my car this works perfectly, even after extended time away from the car. My M535 (without the alarm) appears to not lock out the door locks function after a short period like some others reported here.

So I'd say if you don't have the factory alarm, this won't be a problem.

One more note is about the red wire with brown stripe. There are two wires in the forward bundle that look identical. I got the wrong one first, but no damage was done. Also, my alarm module came with a jumper I had to uninstall to make the unlock feature work.

I hooked up the indicators to the unit by the two wires on the rear plug, and that works perfectly. One blink of the marker lights for lock, two blinks for unlock. Range is better than my OEM systems on my two Lexus' (Lexuses? Lexi?)

I don't remember if I read it on here, but I did see a post that you could unbolt the seat and scoot it forward to make enough room without having to remove the seat from the car. That did work, but only after unclipping the wiring connector from the bottom of the seat. Don't unhook the harness, just unclip it from the bracket holding it in place.

I've only had this unit in place for a few days, but so far I'm pretty impressed with it, especially at the price point of lunch at Chick-fil-a.