2008 Ram 3500 ABS and speed sensor question

dieseldoc · February 23, 2017

I know we deal mostly in fords here but I know some of you guys are dual brand dealers and may be able to help. I have a 2008 dodge ram 3500 dually with a 6.7 cummins, auto trans, 4wd. The truck came in with the ABS/brake light and check engine light on. There was a U0121 fault for no comm with abs module and P0501 for vehicle speed sensor 1 performance. Also had a fault for the exhaust pressure sensor but I was able to repair that with a new sensor and pig tail. I tested the vehicle speed sensor in the rear diff and it was open. Installed a new sensor and test drove, the speedometer/odometer does not work and the lights are still on as well as the check engine light. I cleared all faults before road test. After road test still getting the u0121 and P0501 faults. I started to poke around to check the fuses and found the abs module unplugged. I plugged it back in and you can hear the pump running all the time even key off. My question is will the communication and speed sensor fault in the PCM keep the check engine light on? Does the ABS module need to be programmed when installed? If the module needs to be programmed than I will likely tell them to take the truck to the dealer at this point instead of spending anymore time on it. If the module does not need programming than where is a good resource for diagnostic routine for these faults and schematics for the truck? I normally would just turn this away but it is a good customer of mine and this is his only dodge and he would prefer to bring it to me.

ktmlew · February 23, 2017

TIPM does some strange shit. Just about any electrical fault you can think of.

lmorris · February 23, 2017

According to Mitchel the new ABS module will require programming. I couldn't find much in the way of diagnostics other that DTC's. Nothing concerning the pump always running.