2011DenaliInKY
TYF Newbie
- Joined
- Oct 20, 2021
- Posts
- 13
- Reaction score
- 6
Howdy Everyone!
This is my first post here, glad to see a group of people sharing knowledge! I've got a 2011 GMC Yukon Denali with the 6.2L and 6L80 transmission. I recently suffered a collapsed intake lifter on the #1 cylinder, but was able to get it freed up using a special tool I learned about from Crazed Performance Repair (check out Charles on YouTube if you've not already) and sent the ECM out to LT1Swap.com to have it tuned to turn the DOD/AFM system off. While waiting for the ECM to return, I changed the plugs and wires and buttoned up the intake and everything else I had apart while freeing up the lifter. So on Monday my ECM arrived back to me, I was tickled to death to get my truck back on the road. I had the battery disconnected the entire time the unit was down, and swapped it out for a new one as well. So I plugged the ECM in, connected my battery, triple-checked all the wiring connections, and fired it up. The engine ran great, smooth idle, no immediate lights on the dash, no lifter ticking or engine misfiring, I'm in business!! So I thought... I pulled out of the driveway and started getting all the typical warnings on the dash "service stabilitrak", "service traction control", "service side blind zone alert system" and a check engine light. When I went to pull out onto the road it just didn't feel right, the engine was smooth, but it was like my transmission was slipping, bad! I noticed that the little indicator on the dash to let you know which gear you're in didn't move with the gear selector. I also noticed the trans temp was not being displayed like it usually did. I made a short trip, maybe half a mile, and came back home, livid! I slept on it Monday night and all day at work on Tuesday I kept thinking what I could've missed. I thought it had to be some communication issue between the TCM and ECM. I emailed the tuner, he claimed it was nothing he could've done. I got home yesterday and looked EVERYthing over again. I pulled open the main fuse panel under the hood and started reading some circuit names and came across a 15 amp fuse for "TCM batt" (I think that was the name, I forgot to snap a pic of it) that was missing a fuse. For the sake of trying it, I put a 15 amp fuse in that spot, then fired it up again. I noticed that I didn't get any of the warnings now, the trans temp was displayed, the gear indicator worked. Great! I fixed it! Although, I never pulled any fuses, not once did I even open it up while working on the truck.... I was puzzled, but glad at this point. I went for another test drive, expecting great things, to only be let down again... The transmission is slipping BAD, I barely made it up a moderate hill from a stop. Once it got going, it seemed okay, but from a dead stop I could've gotten up to speed faster running.
So if you've read this far, thank you! Is there a "relearn" procedure for the trans TCM and engine ECM?? Is there something I've missed? The transmission has always been strong in this truck. I flushed the entire system and changed the filter earlier this summer before a trip to Florida and back to Kentucky. I don't understand how it could just suddenly, all at once, fail, just after having engine issues. The truck does have 220K miles, but has been very well maintained and serviced. Just wanted to see if I'm missing something, or if anyone has an explanation for missing fuses other than ghosts or gremlins! Thanks in advance!!
This is my first post here, glad to see a group of people sharing knowledge! I've got a 2011 GMC Yukon Denali with the 6.2L and 6L80 transmission. I recently suffered a collapsed intake lifter on the #1 cylinder, but was able to get it freed up using a special tool I learned about from Crazed Performance Repair (check out Charles on YouTube if you've not already) and sent the ECM out to LT1Swap.com to have it tuned to turn the DOD/AFM system off. While waiting for the ECM to return, I changed the plugs and wires and buttoned up the intake and everything else I had apart while freeing up the lifter. So on Monday my ECM arrived back to me, I was tickled to death to get my truck back on the road. I had the battery disconnected the entire time the unit was down, and swapped it out for a new one as well. So I plugged the ECM in, connected my battery, triple-checked all the wiring connections, and fired it up. The engine ran great, smooth idle, no immediate lights on the dash, no lifter ticking or engine misfiring, I'm in business!! So I thought... I pulled out of the driveway and started getting all the typical warnings on the dash "service stabilitrak", "service traction control", "service side blind zone alert system" and a check engine light. When I went to pull out onto the road it just didn't feel right, the engine was smooth, but it was like my transmission was slipping, bad! I noticed that the little indicator on the dash to let you know which gear you're in didn't move with the gear selector. I also noticed the trans temp was not being displayed like it usually did. I made a short trip, maybe half a mile, and came back home, livid! I slept on it Monday night and all day at work on Tuesday I kept thinking what I could've missed. I thought it had to be some communication issue between the TCM and ECM. I emailed the tuner, he claimed it was nothing he could've done. I got home yesterday and looked EVERYthing over again. I pulled open the main fuse panel under the hood and started reading some circuit names and came across a 15 amp fuse for "TCM batt" (I think that was the name, I forgot to snap a pic of it) that was missing a fuse. For the sake of trying it, I put a 15 amp fuse in that spot, then fired it up again. I noticed that I didn't get any of the warnings now, the trans temp was displayed, the gear indicator worked. Great! I fixed it! Although, I never pulled any fuses, not once did I even open it up while working on the truck.... I was puzzled, but glad at this point. I went for another test drive, expecting great things, to only be let down again... The transmission is slipping BAD, I barely made it up a moderate hill from a stop. Once it got going, it seemed okay, but from a dead stop I could've gotten up to speed faster running.
So if you've read this far, thank you! Is there a "relearn" procedure for the trans TCM and engine ECM?? Is there something I've missed? The transmission has always been strong in this truck. I flushed the entire system and changed the filter earlier this summer before a trip to Florida and back to Kentucky. I don't understand how it could just suddenly, all at once, fail, just after having engine issues. The truck does have 220K miles, but has been very well maintained and serviced. Just wanted to see if I'm missing something, or if anyone has an explanation for missing fuses other than ghosts or gremlins! Thanks in advance!!