Hello
986
fans,
my first post, and I'm coming right away with a problem
.
I bought a
Porsche Boxster
last month. It's a 2004 FL 5 Speed with 58,000 km (garage car and only used in summer).
According to the previous owner (for about two years), the car has the following problem:
When driving (straight ahead), the ABS and PSM warning/error lights come on at exactly 31 mph (50 km/h). This makes a noise similar to an electronic parking brake. After turning off the car, the error disappears (but is stored in the error log).
What the previous owner has already done at a workshop (not a
Porsche
workshop):
ABS sensor check (previous owner couldn't comment on this, so I still need to check the sensors)
Brake pressure sensor replaced
ABS control unit removed and checked at a specialist control unit workshop - no faults found.
I installed a new, original Porsche brake light switch, as well as
new battery
alternator regulator delivering normal readings (around 14 volts)
new tires (still on from the previous owner - very old) - Porsche-approved tires
fresh brake fluid
Unfortunately, the problem still persists; that would have been too easy.
According to Durametric, the following error message is displayed:
Fault code 4460 - Pressure sensor
I found (rennkit dot com) the following solution:
(Diagnostic manual) starting on pages 108 and 109
I performed the following measurements:
1.) Plug connection on the brake pressure sensor is clean and free of corrosion
2.) Check supply voltage of the pressure sensor for short circuit to groound/ open circuit: approx. 5 V ---> 4,98V
3.) Check ground of pressure sensor for open circuit: approx. 5 V ---> 4,99V
4.) Check signal lead of the pressure sensor for short circuit to voltage: < 0.3 V ---> 0 V
5.) Check signal lead of the pressure sensor for short circuit to Ground: < 5 Ω ---> ∞ Ω (some Papers says here "∞ Ω" ???
Find on the german pff Forum
6.) Check signal lead of the pressure sensor for open circuit: < 5 Ω ---> ∞ Ω
I carefully cut open the nylon hose from the ABS control unit connector and couldn't find any broken wires.
My questions:
Can someone tell me the correct value under point 5.)?
How can I resolve the apparent broken wire under point 6.)? Simply run another new wire in parallel?
I'm also a bit confused: I reported the error and the measurements to my Porsche workshop. At first, they thought it was the tires. After confirming that the correct tires were mounted, they suggested it might be the ABS sensors after all. Unfortunately, I didn't get an answer to my question about what the ABS sensors had to do with error 4460.
I'm grateful for any help.
986_er
DId you ever find the solution to the problem? My abs/psm failure light came on, along with tiptronic failure. All of my research suggests it could be the abs sensor. Ordered an
icarsoft
v3 code reader should be in on 7/25/25 and should help me clarify the situation. Also, the car still runs fine, transmission runs fine, brakes work, no power loss. I have a 2008
porsche cayman
2./7 liter engine.
wich failure has your tiptronic?
I still get the tiptronic failure code, but it was secondary to the abs failure which turned out to be a broken abs harness. Right now I have a code that states my bank 1 and 2 are running lean. I'm going to clean the
MAF sensor
, and ordered an
AOS
and will replace it this weekend, hopefully that will take care of the problem. If not I will have to use a smoke machine to look for any possible loose or cracked hoses. As far as the tiptronic issue, I've done some research on it, and it appears they can be refurbished. That will be my
next
project. I just don't want to start replacing things, and not really fix the issue. It just appears that one problem can send a cascading affect down the line so I want to start with the most simple solution, and work my way forward.
