BCM Questions

[08H3]

I have a two part question. I know I the past there have been discussions about the keyless entry and the TPM system not working. The only thing those really pointed to was water getting into the BCM and corroding the common antenna. I've had the same issue, but the BCM shows no signs of ever having water damage. Antenna connector was clean and tight. Does anyone have any other suggestions?

Part two of my question is, if no one has any other ideas, can I swap BCMs from a second identically equipped H3 with no issue and no programming. I realize I will have to use the fobs originally paired with the replacement BCM, but beyond that, any other compatibility/programming issues?

Thanks in advance.

 

[cgalpha08]

Part two of my question is, if no one has any other ideas, can I swap BCMs from a second identically equipped H3 with no issue and no programming. I realize I will have to use the fobs originally paired with the replacement BCM, but beyond that, any other compatibility/programming issues?

Thanks in advance.

No, you have to have the BCM programmed by the dealer so all of the vin coded security stuff matches. I'm sure you can install it, but idk if everything will function correctly. I had mine replaces in 2017 for $800 at a chevy dealer, not sure what it will cost now.

 

[4speedfunk]

I have the same exact issue. It’s not from water. My 08 has 54k miles and sits in the garage 99% of the time. The BCM is bone dry and has never been touched until I took it out last week.

Because the H3 is such an electronic retard, it will often drain a battery if it sits for a month or so. To combat this issue, I disconnected the battery during a recent 3-month vacation. Upon returning, I re-connected the battery, and all was good. EXCEPT the key fobs and TPMS no longer work. I tried the Schwartzzy fix, (unplugging and re-seating the antenna from the BCM). No bueno.

The TPMS will not go into learn mode (key on, p-brake on, bump light switch four times). So I cannot relearn the sensors to the BCM.

The key fibs still don’t work (even with new batteries). Apparently they must be programmed by a dealer (hell no). So it will be manual locks from here on out. I guess I will just ignore the TPMS for the remainder in ownership. Thanks GM.