Another new guy
 

I decided to join this group as I purchased a 2004 ION Level 2 for myself and for my teenager to use around town. Well I screwed something up instantly. Not all instrument bulbs were illuminating. So I pulled the cluster and for some dumb reason I pulled the needles off the gauges to figure out how to replace the bulbs from the front. I don't know my reasoning. So since I could only guess where the needles should be, I was concerned they would be inaccurate, I replaced the complete instrument cluster. I recycled the old one. So then the Service lamp comes on and the odometer and trip meter do not function. I read where the instrument cluster gets its information from the BCM. I also read that if I pulled a BCM and instrument cluster from a donor car and I re-flashed the BCM using the key on - off procedure, all would be good. Went to the salvage yard, pulled the BCM and cluster. Installed them and completed the re-flash procedure ( Or learning procedure for the PAS system). The first time I turn it to start, it tried to crank but stopped. I did the procedure and the security lamp would go away in the run position, but I get no crank start at all. Plug the original BCM in and it starts up fine. I've read several procedures from youtube and web sites and get the same procedure. What did I do wrong and can I correct it? We can drive the car, but have no idea what the mileage is on the odometer since it doesn't work. Simple at home repair or GM dealer? Thank you for your assistance.

Bcm
 

I am using the original BCM and it starts and runs like it should. The odometer and trip monitor do not operate at all. I was told that for the ION series that the odometer was controlled by the BCM and if you switch out clusters (Like I did), you would get the problem I'm having. Of course I found that out after the damage was done. I have a Haynes book for the ION series, but it has a better use as a paper weight as it doesn't even go into detail about the BCM. It will either get repaired or go out on it's departure not working correctly. I just like for things to work correctly, no matter what it is on a car, especially if my kid is driving it.

Saturn ION
 

I'll keep everyone posted, hopefully it will benefit everyone. I ordered a ION service manual on DVD. It's suppose to be what OEM service centers use. I'll look at it when it gets here.

Actually, I just answered an Ion Instrument Panel Cluster (IPC) question for someone else that is quite related to yours.

The upshot is that the mileage is stored in the BCM. As the BCM receives information that is translated into distance traveled, it checks to see if the IPC is "programmed" as the original one that came with the car OR a replacement one that has been reprogrammed to match the original (needs VIN, matching BCM info, etc). If the IPC is correctly programmed, the BCM sends updated data to the odometer on the IPC. If the BCM finds the IPC is NOT correctly "programmed" to match the car VIN and BCM, etc., the BCM will not send updated info to the odometer to display.

The mileage that is "frozen" on the odometer is the mileage on the DONOR car from which the replacement was obtained.
Without getting your junkyard swap reprogrammed by a GM dealer (they usually refuse to do this) or buying a brand new cluster and paying GM to program and install it, I din't think it is gonna work.

Call a few repair places around your area and ask if they can do ECM/BCM flashing.

I have a place in my area that will do flashing (around $150). If I had a TECH 2 device, I would do my own stuff.

They would also have to have the programs for your model and year along with the Tech II.
I believe the easiest way to correct the issue would actually be to flash the cluster, as the ECM and BCM are fine as is. The cluster needs to be married to the BCM. You could do it backwards from the donor cluster but then you are paying for 2 flashes (BCM and ECM)