Long coding for J644 - energy management control unit:

In the long coding procedure the following three battery parameters are transmitted to the control unit:

1. Part number (11-digit)

Example: 000915105AH

Depending on battery capacity

 

2. Supplier/manufacturer ID (3-digit)

Manufacturer Varta                    VA0

Manufacturer Moll                      MLA

Manufacturer Banner      BA2

 

3. Manufacturer data (10-digit)

= 10-digit battery serial number

 

Pin assignment on J644 - Energy management control unit:

Pin 1     Vacant

Pin 2     Vacant

Pin 3     Vacant

Pin 4     Vacant

Pin 5     Vacant

Pin 6     Vacant

Pin 7     Vacant

Pin 8     Bit-synchronous interface to alternator

Pin 9     Convenience system data bus, CAN-High

Pin 10   Convenience system data bus, CAN-Low

Pin 11   Voltage test lead to battery positive

Pin 12   Vacant

Pin 13   Vacant

Pin 14   Fuse (5A) terminal 30

 

General description of J644 - Energy management control unit (= Energy Manager):

The Energy Manager is responsible for energy management in the vehicle. The Energy Manager is a user of the convenience system data bus. It has a purely monitoring function. If a vehicle will not start, the fault should be localised not in the Energy Manager, but in a faulty starter or such like.

Functions:

The Energy Manager

- monitors the energy balance of the vehicle

- monitors the SOC (State of Charge) of the battery

- intervenes in the energy balance of a started vehicle (engine on) with dynamic energy management (e.g. short-term disabling of seat heating in event of a negative energy balance).

- intervenes with non-load current management in a stopped vehicle (engine off), e.g. to shut off consumers such as the TV, in order to maintain the starting capability of the vehicle.

Measured value blocks:

The following measured value blocks contain information: 1, 2, 3 and 4

Coding:

The Energy Manager contains a long code. The coding covers the battery capacitance, its manufacturer and serial number.

Control element tests:

There are two control element tests. In them, the specified alternator voltage can be preset to 15 V or 13.5 V. Measured value blocks 10 and 11 show the following results:

- Specified alternator voltage

- DF signal

- Communication OK./n.OK between alternator and Energy Manager

- Alternator OK / n.OK

- Load response time

 

Adaption:

In the Energy Manager, in adaption channel 1, the transport mode can be activated. No other adaptions are possible.

 

Miscellaneous:

For more information refer to self-study program 287 (Audi A8 '03, Electrical components) or an updated issue of it.