Notes on HHT previous knowledge diagnosis IC - AD54.30-P-2000-02E

HHT 

The instrument cluster is checked using the HHT, there being a choice of the following functions:

1. Version of control module
2. Fault memory
3. Actual values
4. Actuations
5. Variant codings

Additional information can be called up on any test item using the ENTER key.

Variant coding: 

The following alternatives are available under variant coding in the HHT:

1. Move forward the mileage.
2. Read out coding and transfer to a new instrument cluster.
3. Read out/change coding, e.g.

   Engine variant and national variant, fuel tank version, special equipment

Read out the existing variant coding and store in the HHT on an intermediate basis before replacing a defective instrument cluster. Read in the values stored on an intermediate basis again after installing the new instrument cluster. If it is not possible to read out the variant coding stored, the input of all variant codings must be made manually (menu assistance in the HHT).

Move forward the mileage:

Input menu-assisted in the HHT.

When experimenting with the installation of an instrument cluster, do not move forward the mileage as it is not possible to reset the mileage later.