hi I have a 2004 Ram 1500 4x4 SLT 4.7L 5 speed manual tran
I just received a used programmed PCM and my ABS light is flashing.
my scan tool is reporting an ABS code 54 - Shorted Dump Coil Rear
and a ABS code 55 (which i cant find the explanation of that anywhere)

Does anyone know how to test or the location of this
Shorted Dump Coil Rear?
thanks

 

Does your gauge cluster have the brake illuminated as if your parking brake was on and is the vehicle equipped with factory air suspension or air assist for towing ?

 

The dump coil should be a solenoid that allows the air to release on a air ride or air assist suspension system.

 

If your vehicle is not equipped with any kind of air suspension it may need the PCM flashed again.

 

Its just the ABS light flashing. The brake light is not illuminated. I have no air suspension or air assist. So thats what I suspected that the programming was not correct. I have already had to ship it back once because they had the incorrect VIN # and every time the unit comes I have to clear Dodge OEM extended codes. I would think the unit would have been plug and play and initialized for my vehicles specs.

 

Yeah, that would be like trying to get a light bulb without them asking for the engine size, you could check to see if the harness has the plug for the dump and look up the return voltage the PCM is looking for then fool it with a resistor / capacitor setup.

 

However you spent your money and they should provide the service you paid for correctly.

 

yes I agree I did expect a used PCM but a new clean programming of it.

I did research the ABS system in my truck, this is what the manual said -

"There are Two solenoid valves (Isolation and Dump valve) which are used in each antilock control channel. The valves are all located within the HCU valve body and work in pairs to either increase, hold, or decrease apply pressure as needed in the individual control channels.
During an ABS stop the ISO valve is energized which acts to prevent further pressure build-up to the calipers. Then the Dump valve dumps off pressure until the wheel unlocks. This will continue until the wheels quit slipping altogether."

It didnt really indicate how to test anything just removal & install and bleeding.

My need for the PCM stemmed from hitting a huge puddle. It made my idle go high and it ended up being a bad PCM. Probably got wet or shorted - it was a deep puddle during flash flood.

Up to that point my truck was fine - so maybe the puddle also ruined something in my ABS and since my PCM had issues it couldnt report the ABS issue. Im still thinking the new PCM just isnt configured correctly for my vehicle as the manual stated the ABS test doesnt even get kicked off until the vehicle hits 15 mph. I just installed the PCM and turned the truck on to make sure idle was good and the ABS light was flashing immediately. I had other codes as well and my heated mirror indicator light was also flashing. After clearing those codes the mirror light stopped flashing.

Any clue on how to test any of these ABS components?