Hydramaster CDS/GMC High Idle Module?

Matt M

Mar 10, 2017
Real Name
Matthew Mallary
Hey guys, we have a GMC Savanna with the CDS 4.6. The other day it shut down/lost high idle during a job. I switched the machine off gave it a second and tried turning it back on with no luck. I looked under the dash and noticed one of the lights was out on that little module. Luckily, I completely shut the truck off for a minute or two and everything seemed to reset and it worked fine. My question is, does anyone know where I can find some literature on what the lights/codes mean on that little box? I'm not finding anything in the owners manual that I see. Any help with this is appreciated.