PSM ABS Warning Lights

[Lumply]

After driving about 200mts in my 996 C4 year 2000 both lights come on. The brake switch was renewed during major maintenance in October but now the issue has reoccurred and the lights are bugging me. Mileage 117K

I understand that this is a common problem. Is this an auto electrician fix or does the car have to be taken in to a Specialist to resolve?

[Geoff997]

Faulty ABS/PSM wheel sensor. Diagnostic tool will report which one needs replacing.

[Lumply]

Diagnostic shows new brake switch at fault so it's going in to specialist for another BS maybe the 'new one' is faulty. If not this then further electrical investigations needed

[cidersurfer]

I know this is going to sound odd, but a failing MAF can cause this problem. It's well documented if you have a good look online.

[Lumply]

Turned out to be a faulty hydraulic pump but showed up as dodgy brake switch. Wish it was 'cos a lot less to fix!

[jonobigblind]

Both of mine came on my Cayenne a couple of weeks back whilst driving on the M4. I was lucky enough to be near Leigh Delamere so pulled in for a ‘turn it off and on’ reset.

On restart the PSM light went out but then the ABS issues really kicked in and anything above 10mph in the car park caused the brakes to grab on and stop me going anywhere.

Fast forward 4 hours later and I’d been recovered to local garage outside Swindon for a repair. Two ABS sensors later and I’m picking up this morning.

Fingers crossed we both have a few trouble free miles ahead...

[Lumply]

Problem still exists after swapping hydraulic pump (an horrifically expensive piece of kit potentially)
So my Porsche shop will now investigate the electrics at the pointy end of the car. At least I can
still drive it, but without the ABS most of the time.

[majordad]

Might it be a failing battery? This often shows up ABS lights.