Checking brake light switch setting
The pedal must move a perceptible distance of approx. 5 to 10 mm before the brake light lights up
Check (make sure) that the brake light lights up before the pedal meets perceptible resistance or before brake pressure builds up.
Adjusting switch if pedal travel is too small
There are two possibilities to adjust the switch if the pedal travel to the switching point is too small.
1st possibility:
1. Press the brake pedal and pull out the switch plunger. 2. Release the pedal. 3. Check adjustment.
2nd possibility:

• A play-free fit of the switch is no longer ensured after it has been installed and removed several times. The switch must be replaced by a new switch as soon as it perceptibly "wobbles" in its receiver.

• When installing the switch for the first time, it is essential to press it vertically against the bearing surface. It will otherwise not be possible to lock the switch (90° turn), even if great force is exerted.

1. Release switch by turning it 90° and pull it out of the installation opening. 2. Pull operating plunger out of the switch as far as it will go. 3. Reinstall the switch.
Adjusting switch if pedal travel is too large
1. Press pedal and press plunger into the switch by one notch (audible click). The pedal travel to the switching point then decreases by approx. 3 - 4 mm.
2. Check adjustment again.

 

MBailey and 911rs thanks for the explanation.

 

Hi again,
The PSM pump was faulty.The problem is fixed
Thnx everyone who gave me ideas.
Best regards
911rs

 

I have the same P4460.
Changed the pressensor behind on the ABS-unit.
Still the same error !

Now changed the brakepedal-switch.
Now the error is gone !!!!!!!!!

MH

 

hello
i have checked the voltage like its explainded in the work instruction:

problem at step 4: "check signal lead of the pressure sensor for short circuit to voltage" the pin 2 shows 4,99Volt instead <0,3V!

what does this mean "short circuit to voltage between pin 2 of booster pump pressure sensor plug and PSM control module plug pin 26" - how can i solve this?

i am no electro technican so i have probelems to understand?

please can you explain what i have to do?

bye
wolfgang

ps: the abs/psm light apears sometimes after 30min or after 1 min after starting the engine?

 

Hummm this is not easy to troubleshoot. You better take a good look at your wiring for chafing. It seems you got a ground somewhere….I would do a good inspection at the plug and the wires going to this plug...

 

around the wires all look very good
do you know where the pin 2 go - wiring diagram? i dont have the sheets with the wiring?
but if i disconnect the big connector at the abs the pin 2 has no voltage?
yesterday i drove 65km and no psm light comes also not after starting again and driving for 5min!
bye wolfgang

 

It is part of the PSM and it goes directly to the PSM control unit from the pressure sensor….Sadly your problem can be many things, from a bad MAF sensor to wiring or PSM units….There are numerous threads on the subject but lately , lots of owners found the small wires going to the speed sensor at fault. There is a repair kit for this problem. Do you have a code? Do you have access to a Durametric or PST2 ? This solution is not simple because checking your wiring for continuity is not sufficient. The computer is looking at resistance! Here a good thread with problem solved: https://www.6speedonline.com/forums/...already-8.html

 

[QUOTE=jpflip;4255070]It is part of the PSM and it goes directly to the PSM control unit from the pressure sensor….Sadly your problem can be many things, from a bad MAF sensor to wiring or PSM units….There are numerous threads on the subject but lately , lots of owners found the small wires going to the speed sensor at fault. There is a repair kit for this problem. Do you have a code? Do you have access to a Durametric or PST2 ?

i have a durametric professionell.

bye

 

the last step befor changing the psm unit was to replace the boxster main brake cylinder (two 12mm connectors) to the original of the 996 c4 (1x10mm and 1x12mm).

what should i say after 4 days of driving about 250km - no psm no abs light, i am happy.

the fault was produced by myself, die mbc was perhaps faulty i dont know - now the brakes works very good
bye wolfgang

 

Hi.
Do you still have the pressensor number?
I need to order one but I just can't find the number.

With the best regards