pwtr02ss
Full Access Member
Thank you for the update. Hopefully its a simple fix and since you replaced the solenoids and did fresh fluid change, you'll have some peace for mind for another 20-30k miles
Rocket Man's 02 Denali Build Thread AKA "THE BEAST"
- Thread starter Rocket Man
- Start date
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
OP
OP
I just tried to do a datalog with my Autocal but all I got was error $0281 which is no communication with the vehicle. So I pulled the ECM thinking it might be the problem and wanted to look at the connectors but they’re clean as a whistle. Then I remembered that I might have to do something to switch between the Silverado and Denali so I went back in my saved emails from BB and sure enough I need to run the quick setup program from them for the Denali. So I just did that and now it’s raining so I’ll get back to this when it stops. I guess it was looking for an 08 with an ECM and TCM instead on an 02 with an ECM only. 
OP
OP
Ok, got the ECM reinstalled and got the Autocal working. I started recording data and went for a ride, figuring it wouldn’t fail since it was being watched.
But at about 15 minutes in, it did it. I could tell it wasn’t shifting into fourth so I stopped and went to take off. Third gear. I was on a bit of a downhill slope so I just let it start in third a couple times, throttled it a few times to see if it downshifted, but nope. It’s exactly like the trans is in limp mode just like the Silvy was when I had pulled the TCM fuse. I recorded for another 5-6 minutes after the first sign of failure then saved the file. I came home, downloaded the datalog to my pc and sent it off to Justin @BlackBearPerf (Shannon please tell Justin I need him to read that datalog) with a note explaining what’s going on and what I’d like him to look for. I’m thinking it’s either wiring or the ECM. I didnt pull the wiring connector on the trans yet to see if it makes a difference, that will have to wait. My driveway is all wet from the tiny bit of rain we got. I’ll put the truck on ramps later on to see if I can reach it like that. But I’m pretty sure it won’t matter if it’s plugged in or not when it does this.
But at about 15 minutes in, it did it. I could tell it wasn’t shifting into fourth so I stopped and went to take off. Third gear. I was on a bit of a downhill slope so I just let it start in third a couple times, throttled it a few times to see if it downshifted, but nope. It’s exactly like the trans is in limp mode just like the Silvy was when I had pulled the TCM fuse. I recorded for another 5-6 minutes after the first sign of failure then saved the file. I came home, downloaded the datalog to my pc and sent it off to Justin @BlackBearPerf (Shannon please tell Justin I need him to read that datalog) with a note explaining what’s going on and what I’d like him to look for. I’m thinking it’s either wiring or the ECM. I didnt pull the wiring connector on the trans yet to see if it makes a difference, that will have to wait. My driveway is all wet from the tiny bit of rain we got. I’ll put the truck on ramps later on to see if I can reach it like that. But I’m pretty sure it won’t matter if it’s plugged in or not when it does this.
OP
OP
I managed to unplug the connector on the trans and went for a short drive. It feels exactly the same. It did throw a code immediately though, P0740 torque converter solenoid malfunction. So at this point I’m looking at either wiring or faulty ECM. I’m leaning towards the latter but I guess I’ll wait to hear back from BB. I just hope it doesn’t take forever. Luckily I have the Tech2 if I need to buy another ECM so I can program it to my VIN and then use the Autocal to install my tune.
OP
OP
Damn, I just looked up the ECM on RockAuto as well as a couple online dealers. It’s $172 but the core charge is $200.
Tonyrodz
Resident Resident
OP
OP
Not at all plus it’s the wrong p/n. I need a 12200411. It only has 2 connectors. I’m thinking I’ll see if I can find one at a wrecking yard. I see them on EBay for $60-75 but I’d rather get one local so I can check it for corrosion. No telling what part of the country those others are from. It would be worth it to me to pay $50-75 just to see if I can determine if it’s the problem or if it’s wiring. No telling how long it will take for BB to get back to me.
OP
OP
I ordered an ECM from LKQonline.com. It’s off an 02 Avalanche in Idaho with 160k miles so it should be in good shape. It was 50 bux shipped. I trust LKQ, they’ve always treated me good including refunding me 100% on a console I bought from them because the floor bracket was cut up from when they pulled it. The part is guaranteed for 6 months. I figure it will be here before Justin looks at my datalog. This is well worth a shot, at least it should let me figure out if it’s the problem. At the least I get to mess around with programming. 
Tonyrodz
Resident Resident
I don't understand those morons who lists these parts! They can't even get the simplest thing straight.
OP
OP
Yeah I tried looking up an ECM for it on Amazon by year make model and came up with the same wrong part with 3 connectors. I think that’s an 03. The 01-02 is the only one that works for me. I tried using the correct part number to look it up and found nothing on Amazon.
