What are hall sensors?
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Joined: Aug 2025
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From: Texas
2015 ML350, 2020 BMW X7, 2005 LS430
What are hall sensors?
Dealer installed new hall sensors in the receipt they gave, not sure what hall sensors are? Also they applied a "mbclub" code which made the cost free, like $250 free. What are hall sensors supposed to do, couldn't find much online?
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From: In the Shadow of the Tetons
2013 ML350 Bluetec
They can measure rotation. PIcture a disk with magnetic bits at specified intervals on the edge - there could be any number of them, but let's put 360 there so there's one magnet every degree of rotation. The hall sensor is set close to those magnets so it can detect each time a magnet passes by. Using those detections, it sends that input to a computer that can calculate how fast something is rotating (a wheel, for example) or how many turns it has made or how many degrees it has shifted.
They're a part of an ABS brake system; using hall sensors the car knows how fast each wheel is turning. That info can also be sent to a speedometer.
PS: Your google fu needs work...
https://www.google.com/search?q=what...hrome&ie=UTF-8
They're a part of an ABS brake system; using hall sensors the car knows how fast each wheel is turning. That info can also be sent to a speedometer.
PS: Your google fu needs work...
https://www.google.com/search?q=what...hrome&ie=UTF-8
Last edited by rapidoxidation; Oct 7, 2025 at 05:18 PM.
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From: Texas
2015 ML350, 2020 BMW X7, 2005 LS430
So they have nothing to do with the camshaft sensors right? I think I asked dealer to take a look and inspect for any oil regarding the camshaft sensors but they did hall sensors instead for free. Interesting.
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From: In the Shadow of the Tetons
2013 ML350 Bluetec
Well, cams rotate... A hall sensor would help the ECM know what position the cam shaft is at...
I'm not 100% sure of the answer and maybe someone with more direct knowledge than I have will respond, but I would imagine a hall sensor is a large part of the camshaft sensor. Magnets on the camshaft end (a tone ring), a hall sensor to generate a signal from the tone ring.
https://www.google.com/search?q=do+c...hrome&ie=UTF-8
I'm not 100% sure of the answer and maybe someone with more direct knowledge than I have will respond, but I would imagine a hall sensor is a large part of the camshaft sensor. Magnets on the camshaft end (a tone ring), a hall sensor to generate a signal from the tone ring.
https://www.google.com/search?q=do+c...hrome&ie=UTF-8
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From: Australia
2014 ML63, 2018 GLC43, 1929 DB victory six sports roadster
They could well be calling the cam sensors , Hall sensors.
The cam sensors pick up a signal from the reluctor wheel that is pressed onto the front of the Cam shaft. The reluctor wheel has gaps in it that the sensor pics up on. The sensor pics up on the metal section of the wheel.
The cam sensors pick up a signal from the reluctor wheel that is pressed onto the front of the Cam shaft. The reluctor wheel has gaps in it that the sensor pics up on. The sensor pics up on the metal section of the wheel.
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From: Buchanan, SK CANADA
2013 ML350 Bluetec
"Hall sensor" is just a generic term for anything that detects a rotating magnetic field. I've never heard anyone refer to any sensor on any vehicle as a hall sensor. There's plenty of hall sensors on every modern vehicle but they have more precise names. I'm not saying the mechanic who called something a hall sensor was just trying to sound important but some might go there.
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That is the camshaft position sensor https://mbparts.mbusa.com/oem-parts/...rta0xF0-JKRzL4
