I could use some thoughts/guidance on 4460. I have compiled the info available out there.Fault code 4460 -- Pressure sensor

Possible cause of fault

- Short circuit to ground/voltage or open circuit in circuit to control module terminals 25, 26 and 42

- Plug connection on stop light switch faulty

- Adjustment of the stop light switch not OK

- Wiring/ plug connection faulty

- Pressure sensor faulty (replace hydraulic unit)

I have replaced the stop light switch with OEM switches, twice (I read someone had to try 3 different ones...LOL). Brake lights work.

The workshop manual (pasted here, but also attached)

[img]blob:https://rennlist.com/d1d4715d-bbfc-4db3-bf61-ca96cf1f03d2[/img]

[img]blob:https://rennlist.com/3bd98c08-54b6-41f6-b8ba-cfcefdd287d6[/img]

So next is to test for wiring/shorts. I have attached what I think is the correct schematic? I'm not an EE, so I'm not exactly sure how to check this, but I do have a circuit tester.

There are several wiring harnesses that can be purchased not sure how to know which one is required?

Last resort is a new ABS hydraulic unit...yikes.

Any thoughts? TIA.

 

When you replaced the brake light switches did you adjust the pressure button?

 

Carlos, Yeah...well I attempted to. I held the pedal down with a ski pole while I installed the switch, and then slowly released it until I heard the click.

 

I would double check that button adjustment. I have heard that there needs to be a little bit of pedal travel before the switch activates in oder for the ECU to know all is well. If the error code remains I think you are stuck trying harness tests and swaps, but most likely you need a new ABS pump.

One other thing though, have you considered the MAF sensor? Is it possible it could somehow cause the code?

 

Have a larger bore master cylinder? There are some threads on codes that a GT3 M/C can cause.

 

You probably already did a research with "Porsche fault 4460" ...The brake switch seems to be the solution for many people (even new ones fail???) but also the PSM pump in that case : https://www.renntech.org/topic/36074...ult-code-4460/

 

Thanks folks. Yeah JP I've read them all. I think I'm going to try to determine if there is a short, but if that isn't it...$$$

prf, I don't understand your comment?

 

Sometimes changing the brake master for a larger bore unit sourced from a GT3 can cause odd brake codes. People do this to get a firmer pedal feel. If you haven't changed the brake master, then disregard.

 

Thought I would put this to bed..Turns out on the THIRD switch, replacing the brake light switch fixed it. Yes I almost gave up and tried a third time (I read this in another three too) it worked go figure.