MCS 2004
After replacing the rear wheel hubs, I cleaned out all the dirt and gunk covering the speed sensors and now my DSC light comes on and the electronic speedometer is flopping by two miles. Meaning if I am doing 65, it jumps from 67 to 65 erratically.

I was thinking the speed sensors my be damaged, but why were they working before the wheel hub change?
Or could it be they were not working at all and this is why I was able to not perceive a problem?

any help is greatly appreciated

 

I'm going to replace the sensors, but seem like I'm shooting in the dark.

Any know how the sensors read the rotation speed from the hub?

 

The trifecta was caused by one of the rear wheel hubs.

I had replaced it with one a bought from carpartswarehouse, turned out to be a chinese knockoff.

Replaced with an OEM version and everything is back to normal.

 

Interesting since I replaced mine with aftermarket parts (not sure where they were made) and no light...2003 MCS. Probably a defective replacement.