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Remove PSE cutout in 2 minutes, no tools required

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Remove PSE cutout in 2 minutes, no tools required

This is not the first PSE cutout removal modification, but i am sure this is the easiest one, without any side effects. This is a VERY easy to do modification, no tools required. It took me 2 minutes. Look under the dashboard for the PSE relay. Above the fuse box, you will find the different relays. The PSE relay has a sticker "abgasklappen". It is located on the most top left. Pull out this relay. Open this relay by pushing two small screwdrivers in between the relay connector and the


Edited by Eddy
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Eddy - I know this is probably a very stupid and naive question, but I am not very technical regarding what is standard and what is not re the latest incarnations of Porsche 996 ownership. I understand your mod described above, and have looked at your car in the garage (very smart), and I cannot see anywhere that you have had a PSE installed as an extra. So my question is this, I am about to take delivery of a one month old C4S Cab Tip (reg 28-06-04), which has standard tips on the exhaust. Does this car have the PSE as standard and therefore will your mod work as described or do I have to fit a PSE ????? Yours confused in sunny Spain :help:

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Hi Steve,

My car has a factory installed PSE option, and also the dual stainless steel exhaust tips. These are two different options. If your car has PSE factory installed, you will see a switch on the dash board, with the figure of an exhaust tip. On a factory installed PSE, the exhaust is standard open, but closes at 40 km/h and opens again at 70 km/h. The above modification deletes this cutout. Standard open, if you switch the exhaust goes quiet. This is a picture of the part that i cut out of the relay. ( pictures is not very good )

Good luck with your new C4S !


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Are you certain that this hack will not affect the Navigation systems? The other hack -- removal of the four prong bridge -- disables Nav. Do you have Nav? I would hate to do this and then find out that my Nav (PCM 1) no longer functions.

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This "hack" has no side effects at all. I have PCMII, no problem, tested, the door also locks when you drive away. Since you only take away the speedometer information to the PSE and nothing else, all the other circuits that need the speedometer info are being kept intact...

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Thanks for the answer, which sounds logical to me. Are we certain that there are no differences between PCM I and PCM II? I guess that I can check the part number on my abgasklappen relay, which should be confirmation enough, but it would be great to know that there are no other changes in wiring.


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Since we only use an "input" signal, you don't have to worry, there is no output on the relay. (towards the speedo signal) The relay on your car will be differenct, the circuit also. ( ending 01 , 02 and today 03) . As long as you cut out the diode going to pin 1 of the relay, your fine.

If you want to "undo" the mod, just walk in a radio shack shop, ask for 1N4148 diodes ( probably 10 ct/pcs or less) and solder the diode in place.

Best, Eddy

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  • 5 months later...

post-4030-1104771170_thumb.jpgpost-4030-1104771158_thumb.jpgpost-4030-1104771136_thumb.jpgpost-4030-1104771136_thumb.jpgThanks very much Eddy.

I am generally not the type of person that will cut electronic components in my cars, but I was so frustrated with the PSE cutout that I took a chance and the cutout is completely gone. Also, my cab top still opens and closes at the usual moving speeds. The PSE switch still works as intended. I cannot detect any adverse side effects to this mod. However, I do think it would be *very* difficult to solder a replacement diode if I wanted to reverse this mod. I wonder how much a new relay would cost instead.

I took some pictures to document the destruction and to zoom in a bit on exactly which diode to cut. Hopefully they are attached to this post.

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  • 2 weeks later...

Super, cool mod. Eddy.

I like this way better compared to start cutting a lot of wires. As you said Eddy the 1N4148 is a very well known and used diode, should always be easy to get. If there is to much epoxy on the board side, if you ever want to put it on again, maby just mount in on the print side.

Maby the advanced version of this mod would be a little switch so you can actually switch the diode in and out of the circuit. :jump: It would be easy to do.

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Okay, I did this mod, but instead of taking the diode out I just released one of the the pins from the printboard, Took a piece of wire (2 pol) and connected a single pol switch in between.

Now I can control if I want the mod to work or if everything just work as normal (speed cutoff of the PSE).

Switch cost under 1 USD. So this must be the cheapest hack ever :D





Edited by P.Viby
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  • 4 weeks later...

Did this mod on a friends UK 04 996 C2 and took about 15 mins - biggest problem was getting the board out of the relay cover

No side effects (car has PCM2) etc

Very good - highly recommended and was much easier than doing it the original way (taking the bridge out etc) that i did last year on my own car which resulted in the autolock not working any more

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  • 2 weeks later...
  • Admin

0 (zero) HP for the PSE by itself. The cut-out is for some European countries that have noise limits (in town) at those speeds. My understanding is primarily Switzerland.

BTW... if you don't even hook up the valving (just put the mufflers on) then the valves are always open (loud).

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  • 2 weeks later...
  • 1 month later...
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I wanted to add that if you are doing a PSE installation from scratch and have to run the PSE wiring harness (or are having someone do the install for you), an alternative to cutting the diode in the relay is to simply not to install the Speedometer Signal A wire (Grey/Pink) that goes from the Relay socket pin 6 to the jumper plug 1/1 in slot 23 of the relay support. Simply tie that line off. If at a later time you want to activate the speed cutout, it is easy to just install the wire in Jumper Plug 1/1, Slot 23.

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  • 1 month later...

Just a quick note:

I carried out the PSE mod as listed in the 'How to...' section...brilliant!

It works a treat on my UK C4S.

The only think to be aware of was that the diode has changed colour on the relay.

The guide shows an orange diode with a black stripe..mine has a blue diode similar it colour to the capacitor it sits next to...no idea why mine was different...but it took me by surprise when I popped the lid of the relay off.

Just thought I'd let others know that you may find a blue coloured diode, as opposed to an orange one...

The mod still works the same though...

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  • 2 months later...

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