2017 Silverado 3500 Single Axle

BHen5449 · January 16, 2018

Bought a 2017 3500 back in July of 2017. Brand new, had no previous owner. It has driven fine up until about a month ago where at random times when coming to a stop my check engine light would come on and the truck wouldn’t shift out of 1st gear. I would be doing 3k Rpms and only going 20-25mph. it would stay that way for about a day/ day and a half. It’s now been in and out of the mechanics for 2 weeks now and they cannot find the problem. Has anyone else run into this problem or have any ideas what the problem might be. I’ve been told it could be the ECM or the Cellunoid. Thanks

1st diesel truck · January 16, 2018

Do you happen to know or could you find out what code was popping up while the check engine light came on?

Do you or a neighbor own an automotive scan tool to check stored or pending codes? https://www.harborfreight.com/can-obd-ii-deluxe-scan-tool-62119.html ... https://www.harborfreight.com/can-obd-ii-deluxe-scan-tool-62119.html

Also if you're still subscribed with OnStar in any way shape or form; Calling OnStar while in your truck should be able to tell you what code is (or was) popping up and a general indication of why.

One other resort may be checking all your past emails titled something like 'Your past Diagnostics Report from your GMC Sierra HD Crew Cab Diesel' as they may tell you there as well. An example of mine.

Diagnostics Report from your 2017 GMC Sierra HD Crew Cab Diesel as of 01/02/2018