ABS warning light comes on intermittently

[juliany27]

A mate of mine owns a 996 Cabriolet 4 - similar to mine but with much higher mileage. He took it to the OPC in Chiswick for a service last year and because the ABS light came on numerous times. After his wallet was relieved of more than £2,000 [!!!] he picked up the car and within a few miles the light came back on. The car was returned for several weeks whilst the OPC tried to sort out the problem; he was loaned a Cayenne at Porsches' expense.

Eventually the problem was resolved until a few days ago when the problem returned. He is at his wits' end; threats of legal action against the OPC etc.

The car is now on its' way to JZ Machtech for an examination and a second opinion, but has occurred to me that someone might know what the cause of the problem is - and how it can be resolved.

And, before you ask, he did not get a warranty and now bitterly regrets it [] []

 

[Richard_Hamilton]

Julian

This is a quote from Renntech.org regarding a similar complaint on an 01 C4 Cab:

"Check for a P0102 fault. P0102 is the same error you will get if the MAF is unplugged. This can also cause ABS and PSM lights to come on as the DME is not sensing the PSM data and combining it with the throttle position and mass air flow readings.

Second possibility is a (intermittent) bad wheel sensor. A shop with a PST2 could test that for you."

The thread is here: http://www.renntech.org/forums/index.php?s=&showtopic=9365&view=findpost&p=45717

 

[burrow01]

ORIGINAL: Richard Hamilton

Julian

Second possibility is a (intermittent) bad wheel sensor. A shop with a PST2 could test that for you."

The thread is here: http://www.renntech.org/forums/index.php?s=&showtopic=9365&view=findpost&p=45717

And should not charge 2k for the privilege... - what did that cover?

Pete

 

[davel]

I had this with my Boxster. ABS light came on intermittently and then failed and turned the PSM off completely. Turned out to be a bad wheel sensor, cost about 100 quid to diagnose and fix at my independent.

 

[Watty]

Had the same problem with my 1999 C4 - turned out to be the brake pedal position sensor - but DID NOT show up on PST2.

 

[Richard_Hamilton]

ORIGINAL: Watty
Had the same problem with my 1999 C4 - turned out to be the brake pedal position sensor - but DID NOT show up on PST2.

A faulty brake pedal switch wouldn't record a fault in the PSM control module memory, but you could use the PST2 to check if the switch was working correctly.

 

[Guest]

I had exactly this problem with a my2000 C4 6 weeks into ownership - the dealer could not trace the problem and eventually gave me a full refund. They had replaced almost every part inlcuding the ABS pump matrix and all the sensors - many months later when I took my new car there for service I asked what had happened to my old C4 - apparently on a road test following yet another "test fit" and ABS light coming on the technician noticed in the mirror that the brake light reflection showed them to be flickering - upon return to the w'shop he replaced the brake light switch and the ABS light never came on again!!!!!!
Whilst I was attempting to diagnose this problem I was told of MAF failure stories and some things that seemed totally unconnected.........hope this helps?
Regards
Dave

 

[juliany27]

Thanks for the feed-back, folks.

My friend has been in touch with the OPC in Chiswick, the sales director in Reading and in Germany and has also been offered an enhanced PX value if he upgrades to a new 997 C4S cab. He is also looking at a Mercedes SL 350!

He is stating that his final decision depends upon the attitude of the OPC - apparently an e-mail from August 2006, when the problem first raised its' ugly head, has been ignored. Something about marketing and customer care seems to strike me.

And I suppose his $64,000 question is, a 997 C4S cab or a Mercedes SL 350?

What are your views?

 

[juliany27]

I note in the report on his 996 that Phillippe Jeffrey seems to have the same problem as my friend.

I am due to go to see senior management at OPC Chiswick about this issue and will post what occurs in due course.

Obviously, something is wrong; my mate and Phillippe seem to have the same difficulty - and Porsche will, no doubt, have to find a solution very quickly. Quite what it is and how the problem is resolved, is another matter altogether but if everyone with similar problems coordinates complaints and reports solutions, a lot of angst and worry can be avoided.

 

[danofesher]

I had this after I'd just changed my pads. I'd cleaned under the wheel arch. The diagnostic system had recorded a wheel sensor problem (The OPC told me this and showed me where the wheel sensor is). When looking at the wheel sensors it's obvious that if a bit of grot gets in there it'd cause problems. In my case it was just water and it never happened again.