Haven’t had any time to work on truck as my job keeps getting in the way. Did some checking on connections etc but been so long I struggle to remember what I’ve done. Been in touch with ACS, they repaired ecm, and they want me to send them codes and they will get back to me. So was rereading codes(can’t remember where I wrote them down) and performed the instrument cluster test. What I’m wondering is if anyone here can tell me what those codes mean. I got 900, 920, 921, 940, 950, and 999. Maybe my cluster is bad. I really need to get this truck running as I use it to plow my driveway. Any help would be much appreciated.