940 Vehicle Speed Sensor random query

Chooch84 · May 6th, 2020, 11:49

Hi,

In my quest to understand a bit more about my tugboat on wheels, I'm trying to understand the types of sensors that the car has. So the question is, what type of sensor is on the diff cover at the back? Is it a Hall Sensor, Interrupt style, Magnetic inductive, or Magneto-resistive type of sensor?

Hopefully, one of you knowledgable folk may know the answer!

Kr,

T

TonyS9 · May 6th, 2020, 14:29

They use variable reluctance for the ABS systems, I expect the non-abs use this aswell.

The early 740 distributors use hall effect position sensors. Cranks sensors are typically variable reluctance.

Chooch84 · May 6th, 2020, 18:36

Thank you, makes sense as the twisted pair wires from the sensor to the speedo show a "+" & "-". They also branch off to the ABS module.

Laird Scooby · May 7th, 2020, 00:30

Quote:

Originally Posted by Chooch84

Thank you, makes sense as the twisted pair wires from the sensor to the speedo show a "+" & "-". They also branch off to the ABS module.

The -ve on the speedo sensor is taken to 0V inside the ABS module, likewise for the front ABS sensors.

May 6th, 2020, 11:49	#1
Chooch84 940 Noob Last Online: Yesterday 20:50 Join Date: Jul 2015 Location: Birmingham	940 Vehicle Speed Sensor random query Hi, In my quest to understand a bit more about my tugboat on wheels, I'm trying to understand the types of sensors that the car has. So the question is, what type of sensor is on the diff cover at the back? Is it a Hall Sensor, Interrupt style, Magnetic inductive, or Magneto-resistive type of sensor? Hopefully, one of you knowledgable folk may know the answer! Kr, T __________________ 96 945 Classic 2.3 LPT with some mods... To do: Install upper brace, Catch can, install sound deadening (50% done), Fit electric leather seats, repaint! List is endless... 16 BMW 330e

May 6th, 2020, 18:36	#3
Chooch84 940 Noob Last Online: Yesterday 20:50 Join Date: Jul 2015 Location: Birmingham	Thank you, makes sense as the twisted pair wires from the sensor to the speedo show a "+" & "-". They also branch off to the ABS module. __________________ 96 945 Classic 2.3 LPT with some mods... To do: Install upper brace, Catch can, install sound deadening (50% done), Fit electric leather seats, repaint! List is endless... 16 BMW 330e

May 6th, 2020, 14:29	#2
TonyS9 Premier Member Last Online: Jun 16th, 2024 19:56 Join Date: Jul 2009 Location: Holywood	They use variable reluctance for the ABS systems, I expect the non-abs use this aswell. The early 740 distributors use hall effect position sensors. Cranks sensors are typically variable reluctance.

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