Figured I'd post this in case it helps someone else. My 2012 Sonic LT Sedan's instrument cluster LCD has been fading lately - to the point of becoming virtually unreadable.
I bought a used unit, but got the classic dashes on the odometer issue due to the cluster VIN not matching the vehicle VIN.
My first thought was the try to clone the identity of my existing cluster to the new one. I located the EEPROM on the board (a 93LC86C) and connected a flash reader (CH341a) to the chip with clips to try and get a dump. No success - after digging around with a multimeter it turns out the other chips on the board draw too much parasitic voltage - you'd have to desolder the chip to read or write it which I didn't want to risk. I'm rather confident that this route WOULD work, but I didn't trust my soldering skills enough.
Per random stuff on the internet, I found some suggestions that the official GM tools would not flash a used cluster. I couldn't find a new OEM one for a 2012 year so I bought a new one for a 2013 year model, then bought a Topdon X3 and a 30 day SPS2 subscription from GM.
Just a few notes from when I plugged in the brand new 2013 cluster to my car: most everything seemed functional. The odometer displayed. The speedometer worked, the tach worked, etc. The only issues: 1. The menu button on the steering column wouldn't bring up the menu, and 2. The speed and odometer were in km instead of miles by default.
Now, when attempting to flash . . . the GM software won't flash that 2013 cluster to work with a 2012 car. HOWEVER, as a latch ditch effort I did try to program the used unit, which worked absolutely flawlessly in SPS2. If a dealer is saying they can't flash a used unit they're just saying they WON'T do it - not that it can't be done.
In the end it cost me $120 for the Topdon X3, $51 for a 30 day SPS2 subscription. And I now have a mostly new 2013 cluster that I'll probably sell on eBay and just take a $20-$30 loss on. I'm satisfied though, my dash looks normal again
.
I bought a used unit, but got the classic dashes on the odometer issue due to the cluster VIN not matching the vehicle VIN.
My first thought was the try to clone the identity of my existing cluster to the new one. I located the EEPROM on the board (a 93LC86C) and connected a flash reader (CH341a) to the chip with clips to try and get a dump. No success - after digging around with a multimeter it turns out the other chips on the board draw too much parasitic voltage - you'd have to desolder the chip to read or write it which I didn't want to risk. I'm rather confident that this route WOULD work, but I didn't trust my soldering skills enough.
Per random stuff on the internet, I found some suggestions that the official GM tools would not flash a used cluster. I couldn't find a new OEM one for a 2012 year so I bought a new one for a 2013 year model, then bought a Topdon X3 and a 30 day SPS2 subscription from GM.
Just a few notes from when I plugged in the brand new 2013 cluster to my car: most everything seemed functional. The odometer displayed. The speedometer worked, the tach worked, etc. The only issues: 1. The menu button on the steering column wouldn't bring up the menu, and 2. The speed and odometer were in km instead of miles by default.
Now, when attempting to flash . . . the GM software won't flash that 2013 cluster to work with a 2012 car. HOWEVER, as a latch ditch effort I did try to program the used unit, which worked absolutely flawlessly in SPS2. If a dealer is saying they can't flash a used unit they're just saying they WON'T do it - not that it can't be done.
In the end it cost me $120 for the Topdon X3, $51 for a 30 day SPS2 subscription. And I now have a mostly new 2013 cluster that I'll probably sell on eBay and just take a $20-$30 loss on. I'm satisfied though, my dash looks normal again
.