Service Information: Injector classification

P07.16-2778-02

Y76 Fuel injectors

Border Coding Injector Quantity Compensation (IMA)

Modification notes

Information on injector classification

In July 2000, along with the introduction of diagnosis identifier (abbreviated DK) version 0/5, injector classification was phased in for models 210 and 203 with 4- and 5-cylinder diesel engines. Injector classification for all other Diesel powered models will be adopted progressively. The classification can only be clearly recognized and assigned (see STAR DIAGNOSIS CDI 2, control unit version) via the DK 0/5 and higher.

The classification of injectors into 3 levels reflects the fuel metering characteristics of the injectors. This will make it possible to adapt the engine software across smaller incremental ranges to injector tolerances.

When installing or replacing the injector or the engine control unit, the following points must be taken into account as a general rule in the future:

-----------------------------------------------------------------------------------------

Injector

 Classified injectors can be recognized by the part number and marking on the magnetic head (a circle can be seen there which contains a number between 1 and 3). That number indicates the class.

 When replacing an injector the spare part needs to be ordered as specified by the diagnosis identifier.

 After an injector has been replaced in a vehicle with a DK of version 0/5 or higher, the class must be assigned to the corresponding cylinder in the CLASSIFICATION menu item using STAR DIAGNOSIS during control unit adaptation.

A new feature DK 0/5 introduces is the option to shut down individual injectors for diagnostic purposes while the engine is running. For this it is necessary to note the classification beforehand, otherwise the cylinder head cover must be removed for recognizing the class.

-----------------------------------------------------------------------------------------

Engine control unit

Engine control units are downward compatible with all models down to and including CDI 2. Default setting for the engine control units is level 2. When a control unit with identifier DK 0/5 and above is fitted to a vehicle with DK below 0/5, a variant coding test is additionally required.

These boundary conditions also apply if the cylinder-selective assignment of injectors or the engine control unit assignment changes (e.g. due to engine replacement or repairs on the cylinder head etc.).

If the classification is not taken into account on vehicles with diagnosis identifier [DK] as of 0/5, complaints such as smoke formation, uneven or shaking engine running as well as performance complaints are possible.

-----------------------------------------------------------------------------------------

IMA coding

Following the introduction of the following engines:

engine 646 as of engine end number: 271971

engine 647 as of engine end number: 119589

engine 648 as of engine end number: 064541

with CDI 3 1600 bar system converted for these engines to
IMA coding (Injector Quantity Compensation).

These injectors also show the marking of the magnet group, a 6-digit number-letter combination (see bordering in picture), similar to the injectors of the CDI 2 system.

-----------------------------------------------------------------------------------------

The IMA-coded injectors can be identified by the part number
A 648 070 02 87.
(The engines still equipped with injector A 611 070 11 87 or A 648 070 00 87 or A 648 070 01 87 do not have any
IMA coding).

Engine 640 in model 169 and engine 642 in models 203, 211 and 219 have been equipped with IMA-coded injectors since production started.

After the injectors have been replaced, the IMA coding
is entered using STAR DIAGNOSIS under menu item:

- Control unit

- Drive

- CDI 3

- Control unit adaptation

- Injectors injection quantity adjustment

Compatability: