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Weird key issue, truck wouldn't start with primary key. Passlock disabled.

mjferencak

Well-Known Member
Messages
308
Location
Elbert, CO
Could be a faulty wire with the protective casing still in good condition. Might be time for you to park the truck under a tree during a thunderstorm and hope the tree falls.
 

2010H3TAlpha

Well-Known Member
Messages
563
Location
Issaquah, WA
Hahaha, I will keep that in mind.

GM corporate is now telling us that the BCMs we've been getting are probably bad because they have a 2 year shelf life when not in use and are known to do this after "expiration" (WTF???). And guess what, both of the BCMs we tried were sitting on the shelf of GM's Reno, NV warehouse for more than 2 years...go figure. A "newer" BCM arrives on Tuesday next week, but I am very skeptical at this point. Will report back after that.
 

4speedfunk

Well-Known Member
Messages
4,250
Location
Tardville
Or gut it and re-wire it with a harness from Painless. Then you could add a stand alone controller for the diesel swap.


Sent from my iPhone using Tapatalk
 

Traxx

Well-Known Member
Messages
682
Location
PNW
A bcm has a 2 year shelf life? Right. I guess they should put that on the box, 'If not installed, This Bcm will self destruct in 104 weeks'.
 

JPaul

Well-Known Member
Messages
2,436
Location
Way up north, UT
hmm, if they have a shelf life maybe there is a coin cell battery in them that saves info when battery voltage is not applied. I could see the battery dying after a couple years and then it causing issues when you pull power from it. They're old enough a design that they might not have started using non-volatile memory yet (non-volatile means is saves the data even when power is completely removed, like a USB drive or SD card), but that's a pretty crappy design even for back in 2004 or whenever they were first designing these modules.
 

2010H3TAlpha

Well-Known Member
Messages
563
Location
Issaquah, WA
hmm, if they have a shelf life maybe there is a coin cell battery in them that saves info when battery voltage is not applied. I could see the battery dying after a couple years and then it causing issues when you pull power from it. They're old enough a design that they might not have started using non-volatile memory yet (non-volatile means is saves the data even when power is completely removed, like a USB drive or SD card), but that's a pretty crappy design even for back in 2004 or whenever they were first designing these modules.

This seems most likely, and definitely makes me want to disassemble the old BCM to see for myself.
 

2010H3TAlpha

Well-Known Member
Messages
563
Location
Issaquah, WA
Finally drove the truck home today, wow what an ordeal. Here's the final carnage:

Bad ignition switch (first and second switches were both bad)
Bad BCM (possibly caused by the bad ignition switch or just went bad on its own due to age; GM says these are known to go bad at ~7 years). It took FIVE BCMs to find a working one, and even this one we're not so sure about (the wipers started acting weird after I got home). GM says the average BCMs you go through to get a working one is 5-7. WTF.
Bad ECM, possibly caused by the bad BCM, but impossible to know for sure.

The truck now starts and drives like new, so that is nice. But we'll see where the wiper situation takes us.

Edit: Going back to the shop for BCM #6 next week woohoo.
 
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Traxx

Well-Known Member
Messages
682
Location
PNW
The odds of getting 6 bad bcm and two ignition switches all in a row are like one in ten zillion. That they go bad at 7 years is ridiculous, where all the bcm replacement threads?
 
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