I seem to remember accessing the upper ground by removing the a pillar trim from the driver side and it was accessible straight down near the base of the windshield. Im not 100% on that, might need to pull the upper dash cover out a bit. but something tells me it's accessible right in that opening. or it may have been accessible from removing the cluster and reach through an opening in the cavity behind the cluster. let me see if I got pics of it when we were working on it.
Intermittent Serial Data Problem
- Thread starter axekick
- Start date
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looks like it was accessible with a swivel and some extensions through the gap after removing the a pillar trim. then we could look through the windshield and see the ground post.
S33k3r
Full Access Member
Be careful with that knock sensor code. We kept getting that even after we replaced the knock sensors. The wiring in there is annoying -- we had ours replaced -- and make sure you use Delco knock sensors. They originally used an off brand and then "hilarity" ensued. They replaced the knock sensors -- again! -- with Delcos, and did not charge us for it. We've not had issues since.
OP
OP
axekick
Full Access Member
Thank you BigDogYJ. That's very helpful. fixing that up is next on my list.
As far as the knock sensors, I did go ahead and spend the extra on the ACDelco sensors. I'm not too worried about that job, though. I can get the intake off in 10 minutes. I've learned that just moving stuff out of the way is easier than trying to fit my hands where I can't see. Basically doing things the hard way is the easy way, so I have a lot of practice removing intakes on trucks. Now I just need to get quick at removing the dash. It doesn't look that hard, except that I have the full center console so I think that makes it harder.
The truck is at the exhaust shop now getting a normal sounding muffler on it. It had a noisy flomaster dumped under the truck. I'll get to work on it a little throughout next week. I'll update if I make any progress. Thanks everyone for the help and advice so far.
As far as the knock sensors, I did go ahead and spend the extra on the ACDelco sensors. I'm not too worried about that job, though. I can get the intake off in 10 minutes. I've learned that just moving stuff out of the way is easier than trying to fit my hands where I can't see. Basically doing things the hard way is the easy way, so I have a lot of practice removing intakes on trucks. Now I just need to get quick at removing the dash. It doesn't look that hard, except that I have the full center console so I think that makes it harder.
The truck is at the exhaust shop now getting a normal sounding muffler on it. It had a noisy flomaster dumped under the truck. I'll get to work on it a little throughout next week. I'll update if I make any progress. Thanks everyone for the help and advice so far.
OP
OP
axekick
Full Access Member
I got my knock sensors and oil pressure sensor in. I cleaned up the two grounds on the back of the block, cleaned my valley cover and valve covers real good and got it all back together. The rear knock sensor was full of water. It looked like it had been full of water for 10 years. I had to basically break it apart to get it out. I did seal the new sensors in. The knock sensor codes are gone and my oil pressure is reading now. I had to do it twice because I did it in the dark and I put the valley cover gasket on upside down 
so it was leaking a lot of oil down the back of the motor. No biggie. I fixed it over my lunch break the second time around.
I still lose class 2 data, but not as often. I think the warmer weather makes it better. Here's a clue, though. I can tell if there is communication or not because of the dome lights. I noticed the lights came back on one time when I closed the rear hatch. Then, another time I was standing in the back with the hatch open and the com was broken I just bumped the driver side rear wheel well and it came back. I still haven't started pulling off trim to see the wiring harness but I suspect it's in the back. However, I had the rear hatch harness disconnected when that happened so I am sure it's not in the hatch. Maybe it'll be the rear AC module. The rear AC doesn't work right now.
so it was leaking a lot of oil down the back of the motor. No biggie. I fixed it over my lunch break the second time around.I still lose class 2 data, but not as often. I think the warmer weather makes it better. Here's a clue, though. I can tell if there is communication or not because of the dome lights. I noticed the lights came back on one time when I closed the rear hatch. Then, another time I was standing in the back with the hatch open and the com was broken I just bumped the driver side rear wheel well and it came back. I still haven't started pulling off trim to see the wiring harness but I suspect it's in the back. However, I had the rear hatch harness disconnected when that happened so I am sure it's not in the hatch. Maybe it'll be the rear AC module. The rear AC doesn't work right now.
