2013 cascaida with a wabco cab mounted abs module

Im getting constant rolling codes SID 14 FMI 4 SID 13 FMI 6. Wolverine frieghtliner already replaced the abs module and charged my customer 7k to do it. The truck has been everywhere in town and it hasn't been fixed. If i run, the relay test retarder test on my prolink 2 with wabco protcal the abs light goes out.

Im pretty much at loss, i checked the abs power and abs ignition power and the voltages happened to be healthy

 

Im going purely on my customers word here. The ABS module is really shiny so ill take his word for it

 

no its not radar equipped . do you happen to know the location of the engine retarder? it turn that relay off and my ABS light goes away

 

should i check where wire harnesses that go to the cab interface at firewall? the truck is in good shape, ive been working on this truck for 6 years and never had a problem. i feel bad because i told him to take to the dealer in the first place and see what they did to him.

 

This ABS trailer relay spot is sus. Is there more green death underneath?

 

for some reason on my old sam chassis module i wasnt getting proper voltage on the ABS ignition circuit , found a used sam chassis im getting proper ABS ignition voltage now, but still the same the same code.

 

The owner bought a sam chassis and sam cab. I have a sneaky suspiciousion its in the cab harness (which is discontinued) i will report my finding when they're both replaced tonight. This truck has been making me lose sleep for the last 2 weeks