This kind of the intermittent problem is extremely difficult to diagnostic.

But if the diagnostic equipment says ABS sensor is bad even with a new sensor, I will guess either the cables that connect the ABS sensor to the computer module are intermittent or the computer module itself works intermittently.

For my 92 400E, the front speed sensors are connected to the ABS control unit through two coaxial connectors, the cable colors from left front wheel are Grey/Green, the ones from right front wheel are White/Pink, the ABS control module can be easily pulled out of the computer box.

You can try to locate those connectors first, see if the connection is firm, then inspect the cables.

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99 BMW 540i 6-speed 110K Km
03 SAAB 9-5 wagon 80K Km
92 400E (Sold) 245K km
Still missing the days with the Benz, it kept me busy.