PSM and ABS failure

[Sam Quick]

Hi

Can anyone help

Just flagged up on the dash readout
PSM failure
ABS failure

Initially happened after braking this morning

It's not fogged up again on other trips since but is still in the computer under checks.

I did notice a couple of times the abs/pedal pulling in on braking in the dry over the past week or two.

Any one suggest what could be the issue as it appears to be of intermitte fault? 😪

Thanks in anticipation

 

[matsleight]

If you google you'll see loads of different options from cheap to expensive which caused me immense fear when I had it in my turbo. I was lucky - it was the brake light switch behind the pedal so just over a tenner. Mine only seemed to happen on a gentle brake rolling up to a junction and reset the lights each time the car was restarted. If you know someone near you, you might be able to swap theirs and try it or maybe a local indie.
In fact thinking about it when I went to Northway they hooked up the diags and knew straight away it was the switch rather than anything more wallet threatening.

 

[dij999]

Mass airflow sensor failure gives same symptoms and is common cause - had it twice in 8 years - MAF sensor both times.

Turning ignition off seems to resolve - only to return as revs rise.

Quite a few references on the site

https://www.porscheclubgb.com/forum/tm.asp?m=842804&mpage=1&key=MAF&#842859

 

[924nutter]

A faulty throttle body or turbulent air caused by debris behind the removable plastic mesh can also give a pasm and abs fault but this is rare. The error code is 1152 IIRC and the diagnostic tree takes you via mass airflow sensor to throttle control unit, In order of expense brake light switch, MAF, and throttle body. Guess which one fixed mine? I say fixed because once you have got it all apart with the £670 throttle body in your hand and on reassembly you just happen to check out the body of the air filter box and notice a bit of crap you then wonder if the crap was disrupting the air flow giving spurious information. The reason this happened on mine was because someone had fitted a cloth and mesh type performance filter, not a K&N, but had fitted the filter from a Carrera which in essence has the same rectangular footprint but with a cut out to clear the air con pump so part of the mouth of the filter body was not masked properly so some crap got in. I reverted to the std paper filter on Richard's recommendation and it has not missed a beat in 3 years and 14,000 miles. For the sake of your wallet we are all keeping our fingers crossed that it is something as cheap as a brake light switch.

 

[watlina]

As Mat has said try a new brake switch first.

I had exactly the same thing and spent a load of time messing about getting the MAF checked and cleaned and nearly bought a new one. It was the brake switch all along.

http://www.design911.co.uk/fu/prod7161/Switch-brake-pedal-Porsche-997-MKII---987-MKII---987C-MKII-99661311302/

 

[924nutter]

Great to hear. In my case I have not changed the brake light switch, so it cant be at fault because I no longer get the errors. I might just mention that with mine there was a give away of erratic and random high speed idle of anything up to 1,800 rpm.

 

[Sam Quick]

Thanks for the link Andy
I've ordered a brake light switch as a starter.
The code has gone this morning.
Hopefully some intermittent issue that may have cleared but will fit the new switch once it gets her.
😀