Hall sensor error
 

Guys - need the story for the hall sensor error.
Car seems to have a miss fire at certain speeds.
Checked the cpu and durametric says we have a hall sensor error.
I've checked the wires and plugs - all measure good and look good.
Distributor caps and rotas in good condition.

Whats the process to check for the 5v from the plug? Engine running or just in the on position?

Has anyone had a similar problem where they had some miss firing and turned out to be the hall sensor?

Is there a replacement sensor available? Or do you need to get it repaired or you need to get an entire new distributor unit?

Thanks in advance.

That typically occurs on 964s to a greater extent, less noise immunity than the 993 DME ECM, the result of bad spark plugs, wires, and/or distributor caps. The Hall Sensor rarely fails, it's spark noise radiation entering the sensor.

When I rebuilt my distributor, the Hall effect sensor was something I couldn't find a replacement for. Most seem to be 5V or less. You're right its a very robust semiconductor but even so, 25 years of faithful service is very good for a silicon devices in automotive use case. Does anyone have a line of 12V Hall effect devices? There's got to be something out there with Bosch or others.

To OP, the Hall effect sensor is a transistor that responds to magnetic fields, as such it needs to be powered and then subjected to a varying magnetic field. I think you could only test it in use in a running engine by looking at the output on a scope. Maybe with ignition on you could wiggle some ferrous metal in the flux gap and see a voltage variation but it's not a simple ohmmeter resistance check.
If we knew the structure we could check for diode drops in the right polarity but it's a black box from the electrical diagrams.

New Hall sensor arrived. Distributor disassembled.
Anyone know how to get the metal plate that the hall sensor is mounted on removed?


https://cimg2.ibsrv.net/gimg/rennlis...4f22fd6211.jpg
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Where did you get this HALL sensor separately?

My mechanic suspected that same issue because I have occasional misfires too (they've disappeared for now though)

I called and you can't get that part separately from Porsche. You have to buy the whole distributor.

I got two of them - one for spare.

https://www.sonnecy-shop.com/en/hall...honeywell.html

Link posted by boxsey911 on 964 forum about 9 years ago.
Thanks boxsey911.

Thank you.

Ordered one.

Anyone have any tips on how to remove the hall sensor plate from the bottom plate?
Need to get this off some I can remove the old hall sensor.
I'm thinking that it has been pressed on but can't figure out a way to get it off without bending the metal.
Thanks in advance.


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Sonnecy-shop hall sensor
 

Did the hall sensor from sonnecy-shop end up workin in the 993?

Hall Sensors rarely if ever fail! Their fault codes result from ignition noise, e.g. bad wires/connectors, spark plugs, & distributor caps.
Most waste time and money replacing the Hall Sensor.

Sorry for late reply. Yes - it did the job and error has gone. Has not given any errors since.
I also changed the bearings at the same time as the tech said they where perished.
Didn't cost much but took some time to complete.
Now no error and piece of mind.

HI :)

I have the same issue on my 96mod TT, how did you replace the hall sensor on the metal plate?

Best regards
Sondre

Hi Sondre
Happy new year. Hope all is well.
I spend hours trying to get the plate off. It's pressed on and seized.
I ended up finding a pro who rebuilds these things and had them replace the hall sensor at the same time.
The entire unit was serviced - bearings changed - etc.
It's time to do it - 30 year old car.

Happy New Year to you too and thank you so much for your reply :)