ABS Failure

[Karl996]

Apologies - I posted this in the 996 Turbo section so reposting in the right section.

Gentlemen

Looking for some help on a part number and/or advise.

Car is a 2002 996 C2 Manual WITHOUT PASM.

There is a bit of history to my question so please be patient.

1. I had the brake pad warning light coming on intermittently for a couple of weeks.

2. It then stayed on permanently and I changed out the all the brake pads.

3. I also gave the wheel arches a really good wash

4. DID not change the brake pad warning indicator wires as they all looked ok. In fact the brake pads still had some life on them.

5. 2 weeks after changing the brake pads I had an ABS Failure warning light which is permanently on.

Ran a Durametric scan and it tells me that P0501 (Porsche Fault Code 120) - Vehicle Speed and 4210 Rear right speed sensor - op. circ./GND/+ short.

In hindsight I should have realised that the intermittent pad warning was probably electrical/electronic.

My questions are as follows:

1. Do you think the 2 issues are related and

2. If I do change the right rear wheel sensor I'm a bit confused about the part number required.

I've researched and come across 996 60640702 which says front without PASM and also 996 60640600 but that says rear and NO mention of PASM.

I'm also going to change out the brake pad warning indicators at the same time.

Many thanks in advance and regards

Karl

[Karl996]

I should also add a point 4.5

4.5 - the brake pad service light did not go out after the pad change

[Ahsai]

I think one of your problems is step 4 where you didn't change out the brake pad warning sensors. The sensor needs to be replaced once tripped (because physically its internal wire is broken at the contact point by rubbing with the rotor). Once changed out, your brake warning light should go away barring other faults.

Your ABS sensor seems like a seperate problem. I would check the sensor connector and wire to make sure they are OK and not distrured during the brake job before.

[Karl996]

Ahsai - many thanks for your suggestions.

I've found the issue. Took the right rear wheel off and had a good look around.

I found the ends of the speed sensor and brake pad wear indicator wires.

What I did not find was the connector which they need to plug into !!!!!! It almost looks like it's been chewed off.

I guess the answer now is to get the ABS harness repair kit and wire it in.

Does anyone know if you need to cut and splice the wires together or does it connect somewhere. I only managed to trace the wire into wheel we'll and it the disappears.

Thanks again

[JFP in PA]

Ahsai - many thanks for your suggestions.

I've found the issue. Took the right rear wheel off and had a good look around.

I found the ends of the speed sensor and brake pad wear indicator wires.

What I did not find was the connector which they need to plug into !!!!!! It almost looks like it's been chewed off.

I guess the answer now is to get the ABS harness repair kit and wire it in.

Does anyone know if you need to cut and splice the wires together or does it connect somewhere. I only managed to trace the wire into wheel we'll and it the disappears.

Thanks again

Replacement wheel speed and brake pad sensors will have the correct connectors on them, but if you have also lost the harness side connectors, you have a bit of a problem. Porsche does not break up the main wiring harness into too many replaceable sections, and the ones they do sell are anything but cheap or easy to replace. You may be better off getting new sensors and then either trying the scrap yards for a useable section, or going to a VW dealer and seeing if they can match the sensor connectors for you (a lot of the connectors are VW sourced on these cars). And when you splice into the main harness, use shrink wraps to seal the splice against the weather.

[Karl996]

Gentlemen

Thank you for all your responses. I've managed to fix it and thought I would do a DIY if anyone is interested.

[GromitInWA]

Always great to have another DIY!

[Ahsai]

+1 on the DIY. I'm sure someone will benefit from it.