Checking coding data

This function is used to check that the chassis number and coding data between the CAS-control unit and the combination instrument is OK.
The kilometre reading is stored in several of the vehicle's control units, but the memory component for the kilometre reading is located on the combination instrument's circuit board. The memory component can only be written once and cannot be erased. However, it is possible to manipulate the kilometre reading but not without dismantling the combination instrument, which usually leaves visible traces.
Note:
Each time the ignition is turned on the data information between the CAS-control unit and combination instrument is checked. If a deviation is identified, a manipulation point is turned on in the combination instrument.
The manipulation point is turned on in the following cases:
If you suspect that the kilometre reading has been manipulated, the following checks can be performed:
Visual check with the combination instrument installed:
Checking via diagnostics:
Checking dismantled combination instrument:
NOTE! This is only one helpful way to find a possibly manipulated instrument. Detection of damage may be the result of other repairs to the vehicle.
Test conditions:
Procedure:
  1. Start the function.
  2. The vehicle's stored coding data is checked to see that it is OK.
  3. If the coding data is OK, the stored chassis number from the CAS-control unit is shown as well as the stored kilometre reading from the combination instrument.
  4. If the coding data is not correct, an error message is shown instead.