Intermittent Serial Data Problem

[BigDogYJ]

Can you tell me how to access the ground in the dash you're talking about? Remove the top dash cover?

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.

 

[BigDogYJ]

Can you tell me how to access the ground in the dash you're talking about? Remove the top dash cover?

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]

I finally fished the two splice packs out under the dash to try to isolate the problem while there was a loss of communication. However, removing the comb from either one of them had no affect. I expected data to return to the cluster as soon as I unplugged it. I suspect a bad ground. Hard acceleration and bumps seem to cause data to flow or be interrupted. Also, one time I had the back hatch open and I threw my tool bag in there and the lights came on like it caused the data to return. I need to find grounds and modules in the back to check.

My engine has a knock sensor code and the oil pressure sensor seems to be not working, so as soon as I can get a set of knock sensors I'll pull the intake and swap those. While I'm in there I'll replace the valley cover gasket, Intake manifold gaskets, valve cover gaskets, oil pressure sensor and check and clean or repair the two grounds on the back of the block.

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.

 

[axekick]

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.

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