It appears the ABS sensor is hooked up to the intermediate harness that takes it to the ABS controller. The two wire sensor is a permanent magnet type and as the reluctor or tone wheel passes by it, it produces an A/C syne wave. By connecting to ground and the B+ output, you are seeing the ABS controller change the syne wave into a simple on - off square wave. If both test leads were connected to the sensor with female 1.50 metri-pac connectors, you will see a sinusoidal wave form. The amplitude and frequency would increase with the speed of the wheel. The sensor has a magnet with thin mild steel bars that extend a known distance toward the tone ring. A coil of copper wire is wrapped around this assembly, it has resistance and is the most common point of failure. Resistance specs change with temperature but this range is in the diagnostic flow chart if using dealer service information. Step #1 is to confirm customers concern by using a scan tool to view all 4 wheel speeds. If the LF is absent, it is tested first for resistance. If out of range, it is changed first. Always place a dab of dielectric grease on the connector to protect the terminals from moisture & humidity as temps change. The air gap is important but fixed. Some models have the sensor mounted on the dust plate backer. Rust can push open increasing this air gap. The allows for a weak signal which can drop out at slow speeds causing an ABS event on dry pavement. Most are riveted to the backing plate, make it the replacement part. Newer vehicles use a mixture of 3-wire hall-effect sensors to the magnetic material mounted in a radial fashion with tiny lines of “North”, “South” magnetic poles that rotate with the wheel on the bearing. Rust, metal particles can stick creating an erratic signal and fix if cleaned. The bearing w/magnetic is a common failure point as they are exposed to the elements and extreme thermal ranges as disc brakes can get very hot and cool to ambient temps once stopped. New younger engineers make mistakes as experienced engineers retire and know of better designs. ASE Master Tech since 1978.
Really a very competent Prof here
I like that..🇨🇦
KNOWLEDGEABLE tutorial brilliant
Great video thank you very much helpful video
From Nick Ayivor from London England UK 🇬🇧
It appears the ABS sensor is hooked up to the intermediate harness that takes it to the ABS controller. The two wire sensor is a permanent magnet type and as the reluctor or tone wheel passes by it, it produces an A/C syne wave.
By connecting to ground and the B+ output, you are seeing the ABS controller change the syne wave into a simple on - off square wave. If both test leads were connected to the sensor with female 1.50 metri-pac connectors, you will see a sinusoidal wave form. The amplitude and frequency would increase with the speed of the wheel. The sensor has a magnet with thin mild steel bars that extend a known distance toward the tone ring. A coil of copper wire is wrapped around this assembly, it has resistance and is the most common point of failure. Resistance specs change with temperature but this range is in the diagnostic flow chart if using dealer service information. Step #1 is to confirm customers concern by using a scan tool to view all 4 wheel speeds. If the LF is absent, it is tested first for resistance. If out of range, it is changed first. Always place a dab of dielectric grease on the connector to protect the terminals from moisture & humidity as temps change. The air gap is important but fixed. Some models have the sensor mounted on the dust plate backer. Rust can push open increasing this air gap. The allows for a weak signal which can drop out at slow speeds causing an ABS event on dry pavement. Most are riveted to the backing plate, make it the replacement part. Newer vehicles use a mixture of 3-wire hall-effect sensors to the magnetic material mounted in a radial fashion with tiny lines of “North”, “South” magnetic poles that rotate with the wheel on the bearing. Rust, metal particles can stick creating an erratic signal and fix if cleaned. The bearing w/magnetic is a common failure point as they are exposed to the elements and extreme thermal ranges as disc brakes can get very hot and cool to ambient temps once stopped. New younger engineers make mistakes as experienced engineers retire and know of better designs.
ASE Master Tech since 1978.
I like to be your student
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