Here is a bit of what I have figured out.
The odometer value is repeated three times for data integrity. First two bytes are the most significant and the least significant byte is roved over the next 10 bytes since this is written every 1/10 of a mile and the EEPROM is spec'ed for 1 million write cycles. This would stay within spec for 1 million miles.
Engine hours is stored once as four bytes, although I can't imagine needing the fourth byte, divide by 10 since it is recorded to 1/10 of an hour, and it is stored LSB→MSB.
TransTemp 0x000059 0 - Yes 1 - No
Vehicle Settings
0x00005A 0 - English 1 - French 2 - Spanish
0x00005B 0 - Imperial 1 - Metric
The VIN is stored as plain text, that is, the characters are encoded in ASCII and written as hex.
Last 4 characters from label bar code stored as plain text, serial number maybe?
GM 8 digit Part Number for cluster is stored in hex format MSB→LSB
Cluster model ID is 4 large characters from the label. Also stored as ASCII plain text.
Trip meter value is in speedometer pulses, e.g. miles = value/4000, it is stored LSB→MSB. Took me a while to figure out how they were encoding this, but it means that your trip meter is accurate to about 15 inches!. It's probably only updated in volatile memory and stored periodically or at shutdown, otherwise it would wear out the memory location pretty quickly.
Not stored in cluster:
Vehicle settings menu, except language (1) and units (2)
Timer
Fuel used
View attachment 218561
Gray blocks are the same in every memory dump I have looked at, and are mostly zero and probably unused. Still trying to figure out the gauge calibrations, which I think are stored somewhere in the white blocks.
