Rocket Man's 02 Denali Build Thread AKA "THE BEAST"

[Rocket Man]

I just replaced the solenoids, still have to put it back together. I hate laying on my back and working, limbs just weren’t made to bend like that. I unplugged the main wiring connector and had a look. No fluid but there was some black crud in the corner so I used MAF cleaner on the cavity and plug and blew them out with compressed air. I tried to get pics but it was about impossible to hold the mirror in one hand and my phone in the other and hit the button. I’ll have some coffee and go wrap it up, I started at 6:30 this morning to beat the heat. Fingers crossed.

 

[Tonyrodz]

I just replaced the solenoids, still have to put it back together. I hate laying on my back and working, limbs just weren’t made to bend like that. I unplugged the main wiring connector and had a look. No fluid but there was some black crud in the corner so I used MAF cleaner on the cavity and plug and blew them out with compressed air. I tried to get pics but it was about impossible to hold the mirror in one hand and my phone in the other and hit the button. I’ll have some coffee and go wrap it up, I started at 6:30 this morning to beat the heat. Fingers crossed.

More motivated then I am! Not bad for an OG!

 

[Rocket Man]

Well f*ck. I thought that fixed it, it was fine for about an hour during a test drive. I put it through its paces, plenty of shifting including a lot of 3-2 downshifting. Then it happened again.
One thing I thought was a fluke last time I drove it- it seemed like it didn’t want to go into 4th. Well this time that happened again. It was like the trans went into limp mode, felt like it was in third only. So I manually downshifted into first and something weird happened- the battery light and seat belt lights came on and the stereo shut off and restarted. Just for a second, then the lights went off snd the stereo rebooted. I pulled over after a few blocks, it wouldn’t shift into 4th still. I went to take off and it seemed like it was in third so I manually downshifted again and the weird electrical things happened again. So I’m wondering if either I have a bad battery ( it’s 4-5 years old) or a bad PCM or corrosion in the PCM harness. I think I’ll buy a new battery as a maintenance item and when I change it I’ll check the connector at the PCM and go from there.

 

[Tonyrodz]

Well f*ck. I thought that fixed it, it was fine for about an hour during a test drive. I put it through its paces, plenty of shifting including a lot of 3-2 downshifting. Then it happened again.
One thing I thought was a fluke last time I drove it- it seemed like it didn’t want to go into 4th. Well this time that happened again. It was like the trans went into limp mode, felt like it was in third only. So I manually downshifted into first and something weird happened- the battery light and seat belt lights came on and the stereo shut off and restarted. Just for a second, then the lights went off snd the stereo rebooted. I pulled over after a few blocks, it wouldn’t shift into 4th still. I went to take off and it seemed like it was in third so I manually downshifted again and the weird electrical things happened again. So I’m wondering if either I have a bad battery ( it’s 4-5 years old) or a bad PCM or corrosion in the PCM harness. I think I’ll buy a new battery as a maintenance item and when I change it I’ll check the connector at the PCM and go from there.

Would loose or bad grounds do this too? Any codes come up?

 

[George B]

Well f*ck. I thought that fixed it, it was fine for about an hour during a test drive. I put it through its paces, plenty of shifting including a lot of 3-2 downshifting. Then it happened again.
One thing I thought was a fluke last time I drove it- it seemed like it didn’t want to go into 4th. Well this time that happened again. It was like the trans went into limp mode, felt like it was in third only. So I manually downshifted into first and something weird happened- the battery light and seat belt lights came on and the stereo shut off and restarted. Just for a second, then the lights went off snd the stereo rebooted. I pulled over after a few blocks, it wouldn’t shift into 4th still. I went to take off and it seemed like it was in third so I manually downshifted again and the weird electrical things happened again. So I’m wondering if either I have a bad battery ( it’s 4-5 years old) or a bad PCM or corrosion in the PCM harness. I think I’ll buy a new battery as a maintenance item and when I change it I’ll check the connector at the PCM and go from there.

What's your tech2 say? Can you command gears with it?

 

[Stonefort]

Dang! Hey at least you garnered a few more clues....hope you find it. Since other systems went haywire, I would try grounds first since that is probably easier than going through the harness.

 

[Rocket Man]

I guess I’ll have to check grounds. The Tech2 is worthless for this, won’t even communicate with a TCM since there isn’t one, just a PCM so I see no way to communicate with the trans at all. I was just through every menu and there’s zero transmission menus. So no, I can’t command shit. This is so frustrating. I guess I’ll have the battery tested instead of just buying a new one. I’ll have to look at grounds and the trans wiring harness which is a ***** without a lift. I’m so bummed out, this is depressing thinking about if I have to pull the trans again. It’s already hit outside so I don’t even want to mess with it anymore today. I thought it was fixed for an hour and then it ****** up again. Ahhhhhhhh.
Edit: it threw the same code as last time-P0785.

 

[pwtr02ss]

I guess I’ll have to check grounds. The Tech2 is worthless for this, won’t even communicate with a TCM since there isn’t one, just a PCM so I see no way to communicate with the trans at all. I was just through every menu and there’s zero transmission menus. So no, I can’t command shit. This is so frustrating. I guess I’ll have the battery tested instead of just buying a new one. I’ll have to look at grounds and the trans wiring harness which is a ***** without a lift. I’m so bummed out, this is depressing thinking about if I have to pull the trans again. It’s already hit outside so I don’t even want to mess with it anymore today. I thought it was fixed for an hour and then it ****** up again. Ahhhhhhhh.
Edit: it threw the same code as last time-P0785.

Dammit. Its strange that you manually shift it and it works. All of those solenoids are electronic so the trans itself is working. Meaning, if you had HPT, you could put it in 1st gear and command any gear you wanted and it'll shift to that gear.

Did BB ever respond about the pcm not sending the signal to downshift? Again, I've never had an issue with the down shift. Did it just start acting up with the super hot weather you guys have been getting the past few days? I'm wondering if there's a reason its not commanding it or if there's a problem.

 

[Rocket Man]

Dammit. Its strange that you manually shift it and it works. All of those solenoids are electronic so the trans itself is working. Meaning, if you had HPT, you could put it in 1st gear and command any gear you wanted and it'll shift to that gear.

Did BB ever respond about the pcm not sending the signal to downshift? Again, I've never had an issue with the down shift. Did it just start acting up with the super hot weather you guys have been getting the past few days? I'm wondering if there's a reason its not commanding it or if there's a problem.

I never collected a log file to send to BB. I’ll do that I guess. I can manually downshift but it’s starting to not go into 4th now when this happens. This started prior to the heat wave, it was hot but not super hot- maybe on a 90* day. I had just did some work on the stereo prior to it- the mounting bezel had broken so I had pulled the negative battery cable(s). I have a Big3 done so there’s 2 negatives at the battery.

 

[pwtr02ss]

I never collected a log file to send to BB. I’ll do that I guess. I can manually downshift but it’s starting to not go into 4th now when this happens. This started prior to the heat wave, it was hot but not super hot- maybe on a 90* day. I had just did some work on the stereo prior to it- the mounting bezel had broken so I had pulled the negative battery cable(s). I have a Big3 done so there’s 2 negatives at the battery.

I'm at a loss since you can manually command it and it works. Hopefully the log will show something that you can remedy the problem easily. Im sorry I haven't been much help