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abs light on.... HELP!!

n3vsl

Active member
Joined
1 Mar 2010
Messages
43
Hi guys, jus got the car out of storage after a year!!! Fitted a new battery....... ABS light remains on!!!! Also just noticed the speedo has decided to stop working!!! Any ideas??
 
Allegedly the speedo gets it's signal from the front left ABS sensor, so pull that and give it a clean.

Personally I'd take the battery off again overnight, buy a new earth strap tomorrow (cost about a tenner) and reconnect it all with clean and copperslipped connections before touching anything else. :thumb:
 
n3vsl said:
Hi guys, jus got the car out of storage after a year!!! Fitted a new battery....... ABS light remains on!!!! Also just noticed the speedo has decided to stop working!!! Any ideas??

You don't say how far you have driven the car since fitting the battery.

As OC says, speedo is driven off one of the ABS sensors so those two symptoms will be connected.

Have known ABS warning lights to flash on briefly just after starting a car up only to go off after a short distance without any later repeat performances or other problems.
 
Thanx oc will try that....
Distance ive driven car is only a few miles to MOT station, the light remained on all the time, hence the MOT failure! :sad:
 
n3vsl said:
Thanx oc will try that....
Distance ive driven car is only a few miles to MOT station, the light remained on all the time, hence the MOT failure! :sad:

Ouch!
Would have been a better idea to drive to workshop for a diagnosis first and then submit the car to an MoT test.
 
ABS light on all the time and no speedo - I believe that on manual cars it may be the rear left sensor that is responsible for speedo signal - tiptronics and ABD are the front left...probably worth checking both if you're going to jack the car up, etc...

What you ideally need is someone with Durametric or PST2 that could connect up to your car. You're a bit far away in Southampton (2 hr drive in good traffic) otherwise I'd offer - but there may be a member nearer to you that has durametric available.

Alternatively I think TORE B does some diagnostic kit; but I'm not sure if it checks abs fault codes, etc... or is more aimed at the HVAC side of things.

Given that you've only got 7 days for a free retest you'll probably have to drop it into a dealer - the ABS sensors from Porsche are about £140 - plus labour and diagnostics, etc... assuming of course it is the sensor that is faulty.

Hope you get it sorted - definitely worth cleaning up the sensors and also try disconnecting/reconnecting the abs sensor plugs at the left-hand side wheels and also try disconnecting and reconnecting the ABS control module plug (which lives in the front spare wheel well nearest to the bumper on the drivers side of the car - under a black plastic cover which slides up off 4 securing studs to allow access) - I believe the studs securing the module can be removed using a 10mm spanner and that will allow you to unplug, check and reconnect the ABS module.
 
Thnx guys appreciate ur detailed comments & hopefully cure... will look at car tomorrow :eek:
 
Don't forget to do the simple stuff first.

87% of electrical 'faults' are caused by a bad earth. Don't buy anything expensive yet :thumb:
 
award said:
ABS light on all the time and no speedo - I believe that on manual cars it may be the rear left sensor that is responsible for speedo signal.....

Seems unlikely to be on a rear - when you lose traction the speedo would be all over the place :?:

Tiptronic speedo signal is allegedly from the transmission shaft.
 
Hi

You could also check the resistance of each abs plug to ensure that they are all theoretically ok - if you have a multimeter you can measure the resistance from the abs module plug (once disconnected) - each abs sensor should measure between 1600 - 1800 ohms. Also if you got someone to spin the wheel independently whilst measuring that resistance you should see it pulse/fluctuate.

Please see pic attached - also with ref to speedo signal which appears to come from the rear left sensor according to the Porsche 993 manual.

Hope you get it sorted without any unnecessary expense :)
 

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The abs front sensor housings are made of aluminium, oxidise, and pop the sensors.
The speedo, have you tried some percussive maintenance?
>given it a flick on the glass with your finger<
 
Thanks guys for all ur valued comments & info re: abs light........ it turned out to be a simple blown fuse!!!! :thumb: :floor:
Passed MOT straight thru...... happy days
 

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