Well folks, I've got a funny feeling I have a connector moisture issue for my Output shaft speed sensor as the truck is throwing P077C and P0721 at me. It's on my '16 Ram 3500 SLT DRW with the ASIN transmission. Had this happen last year too and only manifests if there's a lot of standing water or slush on the road when driving. Dodge replaced the speed sensor twice (once under warranty) when it happened last, but my gut is thinking its moisture getting in the connector / wiring that's actually the culprit. Anyone have a similar situation before?

 

I have not had that problem yet, but I had a Mercedes MBS motorhome that had rear wheel speed sensors go bad due to moisture. The manufacturer realized the problem after replacing many of them and changed the design to make them moisture resistant.

 

Have you sorted it out ?

 

Yeah, so took apart connector I-255 thinking the issue was likely there as it is soaking wet at the back of the drivers wheel well. Could tell one of the plastic retainers from the male side was broken so the clamping wasn't as tight as it should be. Put dielectric grease between the male and female casings to help seal. Did a continuity test though and found that the was a break somewhere in the T72 supply wire between I-255 and the sensor. So spliced in a jumper wire and all is well again.
Leave it to the Dodge tech in Winnipeg to not have done that simple test and just replaced the sensor 3 times when the wire was chafing and slowly wearing out. Would have found it the first time if he did the troubleshooting associated with the code.