Hello:

Does anyone have pictures or schematics of the ABS wheel sensors showing where they are located? The ABS light comes and stays on occassionally (usually after failing the self-test). Diagnostics of A3 port throws the codes for sensor malfunctions. I want to check if they are really damaged or just dirty. Do I have to raise the car on jacks? I am selling the wagon so I want to fix if possible or disclose to buyers why the ABS light is acting up. Vehicle is 1994 5-spd wagon, non-turbo.

yt850

You also have access to the rear axel sensors via connectors located close to the gasoline pump in trunk right side. Ohm meter shows close to 1k ohm if no broken wiring towards the sensor. These sensors are pretty easy to replace.
My right rear sensor was replaced last year on my 850 -94 at 260k km on it.
Other point to check is the connector solderings on the ABS unit itself.
br Tapsa

Of course the wheels come off, unless you have access to a lift. The sensors are mounted on the suspension, directly above the axle and inboard of the rotor.

Your problem is probably the axle has rust on the exposed teeth that the sensor "looks" at. A wire brush can clean out the rust and dirt.

Much easier access with the rotor off.

Klaus
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Just driving a 1998 V70R :)

Sometimes a wire is broken right at the connector that plugs into the wheel speed sensor. I had that happen on a 1998 V70. In my case, the wiring looked fine until I pulled the connector to find one of the wires was corroded/broken inside the connector.

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'97 850 n/a Wagon, 150K mi ... '98 V70R AWD 105K mi