ABS / PSM Failure - Where to look first?
Discussion
Hi,
I have a 2002 996 turbo with Miltek exhaust and EPL Tune and am again being plagued by ABS / PSM failure.
I first got the messages about six months ago, at that time it came up under braking so I changed the brake perdal switch and all was good for several months.
Now it is coming up on most trips. 99% of the time the message will be displayed the very second that the car is started, If I dont acknowledge the alarm it will allways just simply disapear as soon as I reach exactly 10 mph.
If my driving is slow across town the messages will come up again within 5-10 mins of setting off at no particular time and not under braking. If however I am up to motorway speeds within 5 mins of setting off the message will not re-appear.
I am showing NO CODES using Durametric. I also have a new spare MAF which when fitted does not make any difference
I have done a fair bit of reading and have gleaned the following possible faults from other threads:-
MAF - Brake pedal switch - ABS sensor - Wheel speed sensor - Air leak after MAF - o2 sensor - Steering angle sensor - bad alternator.
My question is has anyone experienced the ABS / PSM failure lights in the same way that I am currently doing so, if so what was the outcome?
Secondly whilst taking into account the times that I am am experiencing this issue and the time when I am not, where would you think would be the best place to start to look.
Any advice greatly recieved. Thanks Shaun.
I have a 2002 996 turbo with Miltek exhaust and EPL Tune and am again being plagued by ABS / PSM failure.
I first got the messages about six months ago, at that time it came up under braking so I changed the brake perdal switch and all was good for several months.
Now it is coming up on most trips. 99% of the time the message will be displayed the very second that the car is started, If I dont acknowledge the alarm it will allways just simply disapear as soon as I reach exactly 10 mph.
If my driving is slow across town the messages will come up again within 5-10 mins of setting off at no particular time and not under braking. If however I am up to motorway speeds within 5 mins of setting off the message will not re-appear.
I am showing NO CODES using Durametric. I also have a new spare MAF which when fitted does not make any difference
I have done a fair bit of reading and have gleaned the following possible faults from other threads:-
MAF - Brake pedal switch - ABS sensor - Wheel speed sensor - Air leak after MAF - o2 sensor - Steering angle sensor - bad alternator.
My question is has anyone experienced the ABS / PSM failure lights in the same way that I am currently doing so, if so what was the outcome?
Secondly whilst taking into account the times that I am am experiencing this issue and the time when I am not, where would you think would be the best place to start to look.
Any advice greatly recieved. Thanks Shaun.
My advice ..
Mine came on when I started moving then went off again - this lasted a few weeks.
It got worse to the point that it came on after a few seconds of driving and remained on until I turned the ignition off.
The fault showed as the fos wheel sensor on the Durametric which I changed- no difference
I then tried the MAF - no difference.
My mate has a garage and he tried his diagnostic - showed ABS module....
Thinking my world was about to collapse I gave up and went to the OPC who had it diagnosed within a few hours.
The ABS wiring loom apparently goes across the steering colum somewhere and eventually it wears thin.
The wire to my fos wheel sensor had an intermittent fault which threw the PSM/ABS lights.
I wished Id just gone OPC in the first place. They only charged me £250 for the repair and even cleaned it inside and out.
Mine came on when I started moving then went off again - this lasted a few weeks.
It got worse to the point that it came on after a few seconds of driving and remained on until I turned the ignition off.
The fault showed as the fos wheel sensor on the Durametric which I changed- no difference
I then tried the MAF - no difference.
My mate has a garage and he tried his diagnostic - showed ABS module....
Thinking my world was about to collapse I gave up and went to the OPC who had it diagnosed within a few hours.
The ABS wiring loom apparently goes across the steering colum somewhere and eventually it wears thin.
The wire to my fos wheel sensor had an intermittent fault which threw the PSM/ABS lights.
I wished Id just gone OPC in the first place. They only charged me £250 for the repair and even cleaned it inside and out.
Thanks for all your replies guys.
I fitted a new battery about 3 months ago, didnt buy the Porsche one which was what was originally on it but the BOSHH direct replacement.
Yes it is definatly a Durametric, a friend of mine who has the same car shares his with me.
The wheels are original but the tyres are 315/30/18 rear and 235/40/18 front. I bought the rears cheap after reading threads on here but had to change the fronts to match. I dont think this is the issue as it ran for a couple of months or so without fault.
Thanks for sharing your experience SIXX TT I think you and Steve are right I need to get it to a dealer, but It will be at least a couple of weeks before I can get the time as the nearest delaer is 1 1/2 hours away. Reading your post rung a bell as when I first got the car I had an audio shop fit an aftermarket stereo, this involved running cables in just the area that you mentioned, perhaps this is when / where the trouble started.
In the meantime my friend is pulling together all the bits and pieces required to do a leak test. This may not be the issue but its something worth doing anyway and all I can do till it goes to the dealer.
I fitted a new battery about 3 months ago, didnt buy the Porsche one which was what was originally on it but the BOSHH direct replacement.
Yes it is definatly a Durametric, a friend of mine who has the same car shares his with me.
The wheels are original but the tyres are 315/30/18 rear and 235/40/18 front. I bought the rears cheap after reading threads on here but had to change the fronts to match. I dont think this is the issue as it ran for a couple of months or so without fault.
Thanks for sharing your experience SIXX TT I think you and Steve are right I need to get it to a dealer, but It will be at least a couple of weeks before I can get the time as the nearest delaer is 1 1/2 hours away. Reading your post rung a bell as when I first got the car I had an audio shop fit an aftermarket stereo, this involved running cables in just the area that you mentioned, perhaps this is when / where the trouble started.
In the meantime my friend is pulling together all the bits and pieces required to do a leak test. This may not be the issue but its something worth doing anyway and all I can do till it goes to the dealer.
SIIX TT said:
My advice ..
Mine came on when I started moving then went off again - this lasted a few weeks.
It got worse to the point that it came on after a few seconds of driving and remained on until I turned the ignition off.
The fault showed as the fos wheel sensor on the Durametric which I changed- no difference
I then tried the MAF - no difference.
My mate has a garage and he tried his diagnostic - showed ABS module....
Thinking my world was about to collapse I gave up and went to the OPC who had it diagnosed within a few hours.
The ABS wiring loom apparently goes across the steering colum somewhere and eventually it wears thin.
The wire to my fos wheel sensor had an intermittent fault which threw the PSM/ABS lights.
I wished Id just gone OPC in the first place. They only charged me £250 for the repair and even cleaned it inside and out.
I'm glad you're happy with it - but incidentally, that's a £65 part they replaced. It's also a fairly common problem (I've had it on both front wheels) so I suspect they knew what it was pretty quickly. Mine came on when I started moving then went off again - this lasted a few weeks.
It got worse to the point that it came on after a few seconds of driving and remained on until I turned the ignition off.
The fault showed as the fos wheel sensor on the Durametric which I changed- no difference
I then tried the MAF - no difference.
My mate has a garage and he tried his diagnostic - showed ABS module....
Thinking my world was about to collapse I gave up and went to the OPC who had it diagnosed within a few hours.
The ABS wiring loom apparently goes across the steering colum somewhere and eventually it wears thin.
The wire to my fos wheel sensor had an intermittent fault which threw the PSM/ABS lights.
I wished Id just gone OPC in the first place. They only charged me £250 for the repair and even cleaned it inside and out.
Update:-
A lucky turn of events today.
My wife's boxster is now sold, the lucky part was that an OPC technician came to check the car out wih the buyer and brought the Porsche diagnostic equipment with him.
He plugged it into my car andImmediately he diagnosed that the issue was with the front passenger speed sensor.
He advised me to check the wiring continuity first, but in most cases it's just a faulty sensor.
I'm not sure why durametric doesn't pick this up though.
Thanks everyone for your help, just goes yo show that there's no substitute for a proper diagnostic.
A lucky turn of events today.
My wife's boxster is now sold, the lucky part was that an OPC technician came to check the car out wih the buyer and brought the Porsche diagnostic equipment with him.
He plugged it into my car andImmediately he diagnosed that the issue was with the front passenger speed sensor.
He advised me to check the wiring continuity first, but in most cases it's just a faulty sensor.
I'm not sure why durametric doesn't pick this up though.
Thanks everyone for your help, just goes yo show that there's no substitute for a proper diagnostic.
ukgatecrasher said:
Update:-
A lucky turn of events today.
My wife's boxster is now sold, the lucky part was that an OPC technician came to check the car out wih the buyer and brought the Porsche diagnostic equipment with him.
He plugged it into my car andImmediately he diagnosed that the issue was with the front passenger speed sensor.
He advised me to check the wiring continuity first, but in most cases it's just a faulty sensor.
I'm not sure why durametric doesn't pick this up though.
Thanks everyone for your help, just goes yo show that there's no substitute for a proper diagnostic.
Good stuff - hope you get it sorted quickly and inexpensively.A lucky turn of events today.
My wife's boxster is now sold, the lucky part was that an OPC technician came to check the car out wih the buyer and brought the Porsche diagnostic equipment with him.
He plugged it into my car andImmediately he diagnosed that the issue was with the front passenger speed sensor.
He advised me to check the wiring continuity first, but in most cases it's just a faulty sensor.
I'm not sure why durametric doesn't pick this up though.
Thanks everyone for your help, just goes yo show that there's no substitute for a proper diagnostic.
As a final update ( I thought I had already done it here but it was only on six speed).
I initially changed the sensor as it was a relatively easy job, but this did not sort the problem.
I then bought a wiring harness repair kit from Porsche and had my local mechanic change it ( it requires splicing into the system) and that fixed the issue.
Apparently the wires break down inside the insulation at the point where it goes through the bulkhead. There is no visible sign and isn't detected in a continuity check unless the circuit is broke at the time of testing.
That was several months back and I haven't had an issue since :-)
I initially changed the sensor as it was a relatively easy job, but this did not sort the problem.
I then bought a wiring harness repair kit from Porsche and had my local mechanic change it ( it requires splicing into the system) and that fixed the issue.
Apparently the wires break down inside the insulation at the point where it goes through the bulkhead. There is no visible sign and isn't detected in a continuity check unless the circuit is broke at the time of testing.
That was several months back and I haven't had an issue since :-)
Shop spent 2 weeks trying to fix ABS/PSM lights. Brake switch, sensors, wiring, even had my PSM computer rebuilt. Turns out the PSM computer was incorrect for my 996. My 996 is C2. The PSM computer is for a C4. If you are experiencing intermittent ABS/PSM problems, first verify that your PSM computer is the correct part for your Porsche.
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