hey guys, i'm getting a code p1687. my speedometer stopped working and the abs light came on at the same time. any suggestions on how to fix this? the non-wokring speedometer seems to have affected shifting, the truck won't shift on it's on, i have to let off the gas for it to shift. any help would be appreciated. thanks.

 

Could be the wheel speed sensor

 

the rear diff speed sensor is most likely gone... it's on the rear diff and takes about 10 minutes to change out and costs about $40 bucks IIRC.

 

thanks! i'll find it in the service manual and replace it. hope it works.

 

ok, checked the service manual , and the only speed sensor i found was the one that is on the tranny. steve00ram360 could you point me to a page in the service manual as to where to find it? thanks

 

hey guys, i found the rear sensor and replaced it. that didn't help. went out and replaced the sensor that is on the tranny. that took care of my code, but the speedometer and abs light is still on. any advice as to what i should do next? thanks.

 

ok, so i sucked it up and took it to the dealer. they are telling me that the abs cab module is bad and that it will cost almost $500 to install and it may or may not take care of the problem. where is this module and can i just go to a junk yard and pull one off any 2nd gen ram and will it work? or is there a way to just bypass this module? any suggestions? thanks

 

Sorry I missed this but the one on the rear diff is on the front side of the diff on the top passenger side...

the "may or maynot" fix it would not cut it. either it's bad or it's not. if it's not, then the dealer should take it out and put yours back in. they should be able to tell you what's bad on it.

is it spitting out a code?

 

yes, it's throwing code 500 and 1687. that's what i figured, that they should be able to check if it's working , none of this maybe stuff. none of my friends has a ram, otherwise i would do a swap to check.