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Old 5th March 2016, 18:18   #2
Mike Noc
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Rover 75 CDT Manual Connoisseur SE, Rover 75 CDT Automatic Connoisseur SE & a Freelander Td4.

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Location: Hampshire
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Ohm meter? If you just checked the resistance of the sensors it won't tell you that much.


With your meter set to volts you can check all the sensors and magnetic reluctor segments in the bearings


The signal voltage changes from 1.7V to 0.7V as each magnetic segment passes the sensor, so jack each wheel in turn and slowly rotate it marking any failures on the tyre wall with chalk.

If the failures are in the same place each revolution then likely a damaged reluctor, and if in random places suspect the sensor or possibly a slightly too big air gap.

Other common failure causes are cable damage to the sensors or corroded plug pins at the ABS modulator.

Here is a front hub being tested prior to fitting. I use an extension cable made up from some old speaker wire and ABS plug and socket which saves pinning through the ABS cables. It also doubles up to allow any sensor to be plugged in to the OSF so that the speedometer can be used as a diagnostic.

[IMG][/IMG]
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