A used part to replace broken one will save much money for your customers,so there are many used parts solutions for each brands cars.But after replacement you need do programming for ECU.Here is a error solution guide on how to solve Benz Vito/Viano W636 W639 dashboard mileage value can not show after dashboard replacement.
Procedures:
Remove dashboard
Remove 25LC640 chip from dashboard PC
After then use CG100/CG100X or CGPro to read out data
Below picture show the data structure
Red:mileage value,change all to “0”
Blue:Sync ID for dashboard and key,need change it by current key SSID
Now use CGMB to read out current keys information,include SSID and key position
According to the above key information, we infer that the SSID of the first key is: 68 6F 44 40
01SSID value algorithm
68 6F 44 40 Negate: 97 90 BB BF
97 90 BB BF From back to front: BF BB 90 97
02 SSID verification algorithm
BF is negated to get 40, so the check of BF is: B0 4F
BB is negated to get 44, so the check of BB is: B4 4B
90 is negated to get 6F, so the check of 90 is: 9F 60
97 is negated to get 68, so the check of 97 is: 98 67
03 Blue box position input
BF B0 4F BB B4 4B 90 9F 60 97 98 67
Write the data you modified before back to 25LC640 chip,then the dashboard will show correct mileage value
Note:If the original 25LC640 chip data work,you just need replace the original chip to the second dashboard PCB.