axekick
Full Access Member
I'm back from a long time ago! I bought an 05 Suburban to fix up but I may be in over my head. I've learned a bit about this system since I got the truck home but apparently some module is interrupting communication through the class B serial data system. Most of the time, the gauges are all zeroed out except for speedo and tach. When it's like that, the shift indicator does not underline the current gear. Also when it's like that, dome lights don't work, auto door lock doesn't work, etc. etc.
It's my understanding that all of the modules communicate through one wire and if one shorts out or malfunctions it can throw off the whole system. I don't have a scanner that can give me module status but I do have HPTuners. during the times when the gauges are working, I can read/write with my tuner. When the gauges are malfunctioning I can't connect. So I have plugged in my scanner and started unplugging modules to see if it lets me connect and so far disconnecting the ones I've tried has not made a difference. So I think I've ruled out the BCM, gauge cluster, HVAC, Transfer case, Radio, and maybe the ABS, although when I messed with that one the gauges worked for just long enough that I thought I might have solved it.
From what I've seen around here, it looks like there might be an expert on this system that can help me diagnose the problem. If I have to, I'll pull the entire interior and check every module and ground and look for any shorts along the harness. In the worst case I think I could get something like this: https://currentperformance.com/shop/nbs-99-07-silverado-sierra-suburban-tahoe-integration-harness/ which appears to replace the whole body harness.
Does anyone have any obvious or not so obvious things to check?
It's my understanding that all of the modules communicate through one wire and if one shorts out or malfunctions it can throw off the whole system. I don't have a scanner that can give me module status but I do have HPTuners. during the times when the gauges are working, I can read/write with my tuner. When the gauges are malfunctioning I can't connect. So I have plugged in my scanner and started unplugging modules to see if it lets me connect and so far disconnecting the ones I've tried has not made a difference. So I think I've ruled out the BCM, gauge cluster, HVAC, Transfer case, Radio, and maybe the ABS, although when I messed with that one the gauges worked for just long enough that I thought I might have solved it.
From what I've seen around here, it looks like there might be an expert on this system that can help me diagnose the problem. If I have to, I'll pull the entire interior and check every module and ground and look for any shorts along the harness. In the worst case I think I could get something like this: https://currentperformance.com/shop/nbs-99-07-silverado-sierra-suburban-tahoe-integration-harness/ which appears to replace the whole body harness.
Does anyone have any obvious or not so obvious things to check?
