2005 GMC 3500 UPDATE
I have recently purchased 2005 GMC 3500 diesel 6.6. Drove the truck this morning everything was fine. When I left work truck shuddered between 50 and 60 mph when under acceleration transmission temp w...
Forum Discussion
drcook wrote:
You should also have someone with a good code reader look and see if there are any historical codes. An Autozone type (cheap) will not see the historical codes. You may end up taking it to a dealer for diagnosis and code reading. GM garages use what is called a Tech2 (or above) to work on these trucks. The Tech2 is a 2 way diagnostic tool and can program/set switches in the CPU. I have a good, but 1 way scanner that lets me see everything about my truck. Unfortunately a good code reader/diagnostic tool is a bit north of $500.00. We spent $1200 but I can see the injector balance rates, all the other PIDS, rail pressure, commanded vs actual etc etc etc. There is a lot to these trucks.
If you take it to a dealer to have them scan it with a Tech2 they will be able to tell if someone stuck a different program into the ECM. If they did, they will (for a charge of course) reprogram the truck back to stock.
As long as that truck has not been hurt, it will make you a good platform once you get it tweaked back into shape.
I don't mean to burst your bubble, but you could have purchased an Edge insight monitor for around $300 for the older version (Which will be discontinued soon in favor of the $399 version) that will read all the info and PIDS you referenced. Im assuming whatever you purchased will read TCM codes, which is key on an Allison truck.
The OPs problem certainly doesn't sound good, but I will note that the Dashes in these trucks are not always spot on with the temp gauges and I would hook up a scan tool and see what the ECM data for trans temp is. 200* is high.
