DamThatRiver24
Member
Our 2010 Tahoe LTZ has been an absolute beast since we bought it at roughly 125k; it's got 188k now and I've kept it in pretty solid condition the whole time in spite of heavy usage...and have avoided a lot of the typical problems with these things. Thing still easily books for 10k in my area and I'm not in a position to buy another car, so in no way do I want to give up on it over anything minor.
But we're currently involved in an electrical saga that has us at our wits' end, and I'm not sure how to approach things.
So every roughly 400 miles (or maybe 40-50 hrs runtime) it'll go into limp mode, primary code is the top-level U0100 (lost comms with PCM) with a zillion system codes behind it, many unrelated to each other. It'll start up and be just fine in 15-20 minutes...until it does it again at roughly the same interval.
It has since been in and out of two shops (including an automotive electronics specialist) for over a month and no one can seem to figure it out. But I really suspect they're being lazy with diag, and more importantly, I think we're starting to get kicked to the back burner.
-I did some initial surveying of the major grounds, harnesses, and wiring, and didn't come up with anything and didn't really have the time, so I took it to our primary mech.
-They initially cleaned up a couple of grounds (they didn't specify, but I'm assuming the two main BCM grounds [seat and fender], which I had already looked at) and sent it back to us. That didn't do the trick.
-I then replaced the battery after the next incident, as the battery was near end of life and I was getting ready to do it anyway as preemptive maintenance. They had also suggested this would be the next step if the grounds weren't the issue, and that correlated with a lot of what I'd read on here. But that didn't do the trick.
-Took it back to them; after consulting with the electrical shop, they decided to swap out the main engine fuse box with a used one....which not only didn't solve the issue, but temporarily caused all sorts of other little issues (no turn signal, etc.) because the used one had all sorts of corrosion on the fuses. Lol. Anyway, fixed the new unrelated issues, original problem recurs, back to the shop it goes...where it has now been sitting (untouched) for another week.
I'm frustrated because while I'm not an idiot, I don't have a proper scan tool (just a cheap code reader and for some reason it can't get past the U0100 code...only reason I know about the other codes is the shop told me) and don't have the knowledge/experience these guys have. But also, the only other alternative is our actual GM dealership, which has a terrible and declining reputation and I'm afraid they're just gonna start firing the parts cannon at it too, potentially just going through and replacing hundreds/thousands of dollars worth of modules without actually taking the time to diag properly. So I'm not sure where else to go or what to do.
This is our primary vehicle and long story short, being without it has been both expensive and stressful as hell. But I'm nervous about trying to take things into my own hands. Besides tracing all the wiring myself, I don't really have any other ideas except for maybe the Battery Redistribution block or the BCM (or even the computer) itself...but neither shop seems to think they're the issue (and I have no idea if they've tested them).
Any ideas, anecdotes, solutions, etc.? And when do you feel is it okay for a customer to step in and make suggestions or even try to take it somewhere else? Thinking about maybe taking it to our Ford service center instead, as we've had some good experience with them and they're about the only option left since again, our GM dealership has a terrible reputation. Bottom line is that two third party shops (one of whom is a specialist) can't get it sorted and don't seem to want to actually trace where the bad ground/wire/connection/module/whatever the hell it is, is.
But we're currently involved in an electrical saga that has us at our wits' end, and I'm not sure how to approach things.
So every roughly 400 miles (or maybe 40-50 hrs runtime) it'll go into limp mode, primary code is the top-level U0100 (lost comms with PCM) with a zillion system codes behind it, many unrelated to each other. It'll start up and be just fine in 15-20 minutes...until it does it again at roughly the same interval.
It has since been in and out of two shops (including an automotive electronics specialist) for over a month and no one can seem to figure it out. But I really suspect they're being lazy with diag, and more importantly, I think we're starting to get kicked to the back burner.
-I did some initial surveying of the major grounds, harnesses, and wiring, and didn't come up with anything and didn't really have the time, so I took it to our primary mech.
-They initially cleaned up a couple of grounds (they didn't specify, but I'm assuming the two main BCM grounds [seat and fender], which I had already looked at) and sent it back to us. That didn't do the trick.
-I then replaced the battery after the next incident, as the battery was near end of life and I was getting ready to do it anyway as preemptive maintenance. They had also suggested this would be the next step if the grounds weren't the issue, and that correlated with a lot of what I'd read on here. But that didn't do the trick.
-Took it back to them; after consulting with the electrical shop, they decided to swap out the main engine fuse box with a used one....which not only didn't solve the issue, but temporarily caused all sorts of other little issues (no turn signal, etc.) because the used one had all sorts of corrosion on the fuses. Lol. Anyway, fixed the new unrelated issues, original problem recurs, back to the shop it goes...where it has now been sitting (untouched) for another week.
I'm frustrated because while I'm not an idiot, I don't have a proper scan tool (just a cheap code reader and for some reason it can't get past the U0100 code...only reason I know about the other codes is the shop told me) and don't have the knowledge/experience these guys have. But also, the only other alternative is our actual GM dealership, which has a terrible and declining reputation and I'm afraid they're just gonna start firing the parts cannon at it too, potentially just going through and replacing hundreds/thousands of dollars worth of modules without actually taking the time to diag properly. So I'm not sure where else to go or what to do.
This is our primary vehicle and long story short, being without it has been both expensive and stressful as hell. But I'm nervous about trying to take things into my own hands. Besides tracing all the wiring myself, I don't really have any other ideas except for maybe the Battery Redistribution block or the BCM (or even the computer) itself...but neither shop seems to think they're the issue (and I have no idea if they've tested them).
Any ideas, anecdotes, solutions, etc.? And when do you feel is it okay for a customer to step in and make suggestions or even try to take it somewhere else? Thinking about maybe taking it to our Ford service center instead, as we've had some good experience with them and they're about the only option left since again, our GM dealership has a terrible reputation. Bottom line is that two third party shops (one of whom is a specialist) can't get it sorted and don't seem to want to actually trace where the bad ground/wire/connection/module/whatever the hell it is, is.
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