No Speedo

This morning my jeep was fine but as soon as i got on the freeway my speedo dropped to nothing and my check engine light came on. i pulled over and checked things out, speedo connector on the T-case, fluids, vaccum all the usual but there was nothing wrong. when i got home i too the speedo out and some of the teeth are partally missing, could this stop it from working all together and cause the engine light to come on? this one has me stumped, any input would be appreciated!

B.T.W. i have a 95 4.0L with a NP242 and an electronic speedo

if teeth are actually missing, it is very likely the reason you have no speedo, not sure if it would cause the engine light to come on though... you could take it to auto zone and they offer a service to check it for no charge... would be able to tell you why it's on.

i pulled the speed sensor and some teeth were missing. the trouble code was 15 which is no signal from speed sensor under load conditions. i ordered the drive gear from the dealer and it sould come soon. What could possibly cause such a thing to happen? the housing of the speed sensor looked almost if it had been melted could the heat actually change the angle of the drive gear?