Mercedes Vito Viano W636/W639 Not Show Mileage CGDI solution


It is a common phenomenon that Mercedes Benz Vito/Viano, W636/W639 doesn’t show mileage at all after replacing second-hand instrument cluster.

Cluster (new type ) Eeprom: 25LC640 (25640)

Benz W636 Not Show Mileage 1


Disassemble the instrument cluster, remove dashboard, locate chip IC 25LC640, read 25640 chip data with CG100 or CG Pro 9S12 programmer

Benz W636 Not Show Mileage 2

Benz W636 Not Show Mileage 3

Save eeprom.


How to modify data:

The red frame is the mileage area, which can be changed to 0.

The blue frame is the synchronization ID (SSID) of the instrument cluster and the key, which needs to be modified according to the SSID of the current key.

For mileage to show, mileage+ssid must match EZS.

Benz W636 Not Show Mileage 4

Read working key information with CGDI MB. Write down the SSID and key position

Benz W636 Not Show Mileage 5

Benz W636 Not Show Mileage 6

Current key position: 2

SSID:69 6F 44 40


The first key SSID should be 68 6F 44 40


01 SSID variants
68 6F 44 40 transferred 97 90 BB BF97 90 BB BF Back to front: BF BB 90 97


02 SSID Verification 
BF=40,  BF verification: B0 4FBB=44,  BB verification: B4 4B

90=6F,  90 verification:9F 60

97=68,  97 verification:98 67

03 Input the following value in blue frame 
BF B0 4F BB B4 4B 90 9F 60 97 98 67

Benz W636 Not Show Mileage 7

Before modification vs After modification

Benz W636 Not Show Mileage 8

Write the modified chip data to cluster.
Reinstall instrument cluster to vehicle.
Dashboard shows the correct mileage, all data work properly.