Dear Mike91,

Hope you're well. I concur in your view, that the under-body environment can be harsh. That could certainly degrade the exposed wiring harness, for the ABS/speedo sensor, as Marlin Mangels reported.

At an extreme, the water-tight seal - where the wires enter the sensor head - could fail, as happens with the crank (RPM) sensor. I'd have thought such deterioration would be as obvious with the ABS/speedo sensor, as it is with the RPM sensor.

Further, if the ABS/speedo sensor in the differential fails intermittently, that should cause the ABS system warning light to come on and to stay-on after start-up. Marlin Mangels did not report any ABS system warning light.

Absent signs of failure in the water-tight seal, where the ABS/speedo sensor's wires enter the sensor head, it seems more likely that the speedo would have failed.

While accessing the speedo's printed circuit board is a tad time-consuming, an inspection takes a few seconds. Either there's some sign of failure - usually discoloration caused by over-heating or a leaky capacitor - or there's no discoloration.

Hope this helps.

Yours faithfully,

Spook