pwtr02ss
Full Access Member
I have not. I'm sure you can google and see how to test it.
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Rocket Man's 02 Denali Build Thread AKA "THE BEAST"
- Thread starter Rocket Man
- Start date
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I started on the grounds. All I got done in an hour was the battery cable where it connects to the frame near the radiator core support and on the engine block. Neither looked too bad, no visible corrosion and no issues with the cable or logs. I wire brushed everything with a rotary tool and reassembled. The engine block one tried to kill me, I couldn’t reach it with my hand and needed 2’ of extensions to get to the bolt and that was at an angle to the bolt. Which I dropped and took 20 minutes to fish it out. 
It took forever to get that bolt started. Now it’s 90* and the sun is right overhead so I’m on break. Prolly for the rest of the day. Hey at least I started!
It took forever to get that bolt started. Now it’s 90* and the sun is right overhead so I’m on break. Prolly for the rest of the day. Hey at least I started!
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According to alldatadiy the next ones- 103, 104, 106, 107 are all at the top of the bell housing which I don’t think can be accessed without dropping the rear of the trans down and even then it takes about 4’ of extension to reach the nuts on those studs. Anybody messed with these particular grounds?
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I was looking to see if I can get to the grounds at the back if the engine from above - not a chance- and discovered the rubber elbow on the vacuum hose that goes to my SC bypass actuator was completely rotted. I wonder if that’s the source if my vacuum leak and is the reason for my P0300 random misfire code I keep getting. @randeez you probably know what this device does, I don’t even know but it is connected to a vacuum line right? And if that hose was disconnected what would that do? I was able to use a length of hose to replace the elbow.
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Found a wire unplugged and went AHA! Joking, it was the block heater. Must have came unplugged when I replaced the front diff. Then since I was under there, I replaced the steering stabilizer bushings with the new Energy Suspension ones I had bought.
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Cleaned G302, front of fuel tank @ LH frame rail and G403 rear of fuel tank @LH frame rail and inspected G305 & 306 inside cab @ L&R C pillars. Those two were super clean. Cleaned pos & neg battery terminals. Im not really finding anything.
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randeez
Full Access Member
I think that just opens when it sees vacuum, cruising, idling etc. With out the vac line to it, it would just be closed at all times. nbd on the s/c side but on the vac side you might get a maf code or something. P0300 I thought was random misfire?
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No MAF codes. And yes P0300 is random misfires, I was thinking intake manifold leak, not sure where this plumbs in at so I was grasping straws.
I saw it on there a few weeks ago, let me check my watch history and see if I can find it for you.
@ 11:25 for what it's worth.
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Thanks. He didn't say much other than look for fluid in the cavity or it can cause all sorts of problems. I'm still debating on replacing the internal harness along with the pressure switch and anything else in there that could be causing my issue, maybe the tcc solenoid IDK. I'm kinda running out of possibilities. I was thinking about how I could check resistance in the wires in the external harness between the trans and the PCM. I was really expecting Justin @BlackBearPerf to have looked at my data log by now and hopefully tell me if the PCM is commanding the shifts. I know when I looked at that cavity on top of the trans through a mirror it did have something black in a corner but it looked like some crud had fallen in and not trans fluid coming through. It's super hard to see in it though, have to hold the mirror just right and then shine a flashlight at the mirror and bounce light into the cavity.
Call him up and ask him. Cant hurt?
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Call Justin? They don’t do technical help over the phone. Only sales.
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I was looking at the main positive wires and was grabbing and pulling on the main positive lead from the alt to the battery. I had installed a megafuse and 1/0 cable in place of the wimpy stock one when I did my Big 3. I noticed one side of that cable where it connects to the megafuse was loose, I could easily twist it back and forth. This might be the issue I was having when I put it into park and was losing power momentarily. The doors unlock right as I do that and that might have caused a momentary surge in power draw and if the alt wasn’t making good contact things might have been momentarily dropping voltage. Regardless, I do know the alt needs to be working good and if it’s hot outside like it has been the fans are running, ac was running and the system is drawing a lot of power. Then hit the door locks and who knows what happens if the alt wire wasn’t making good contact. Im almost tempted to put it all back together and test it, but I’ll leave it for now and continue with troubleshooting. I’ve done all the grounds I can, the only ones left require at least lowering the back the transmission to get to the top of the bellhousing and possibly removing it. If I remember right I have to pull the transfer case to drop the back of the trans and I’m not doing that.
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Put it all back together and drove it for awhile. Same thing. I’m just going to wait until Blackbear gets back to me after reading my data log. I’m running out of possibilities, might still be the internal harness or something.
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BB just got back to me and said the PCM is commanding shifts like it’s supposed to do it looks like it must be the harness. So I’m waiting on Performabuilt to get back to me so I know for sure I’m ordering the right part. I’ll replace the manifold pressure switch too and if there’s anything else like the TCC solenoid I’ll do that while I’m in there. I sent a PM to you @pwtr02ss to borrow that harness tool. Hope it’s not the external harness, I guess I’ll see if the internal one fixes it.
pwtr02ss
Full Access Member
PM returned. I'll send tracking once I have it
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I’m thinking I’ll be buying HP Tuners and starting to do my own tuning. I just need to know if I can do some slight mods to my existing tunes instead of starting from stock since I’m not ready for that. That way I can look at data myself and command shifts. Frank @Performabuilt says he’d like me to disable the 3-2 shift solenoid since he says it’s not needed with their builds and can cause limp mode. I have wanted to start doing my own tuning, maybe it’s time. I’m out of patience with Justin and his 2 week wait for an answer. They’re ok for getting your tunes but for any technical help like this not so much.
