Bulb Test and Engine Running Recognition

208 as of August 99
210 as of July 99

Networking:

Bulb test
A bulb test is carried out when terminal 15 is on. All the indicator and warning lamps (where fitted, depending on equipment and national variants) are actuated with the exception of the
- left turn signal indicator lamp (A1e1),
- right turn signal indicator lamp (A1e2)
- preglow indicator lamp (A1e16)

The bulb test only takes place as long as terminal 61 is on low level (terminal 61 < 9.4 V) (generator is not yet working) and the engine speed is less than 200 rpm. If there is no fault, the lamps go out when the engine runs.

Engine running recognition1 terminal 61e
The instrument cluster (A1) links the discrete terminal 61 signal and the CAN message engine speed to the CAN message of terminal 61e engine running recognition and to the corresponding discrete signal.

Terminal 61e is, for example, required by the injection system control module (N3) and traction systems control module (N47). This signal can assume "high" or "low" status. It is therefore "low" when terminal 61 is "low" and the engine speed is less than 200 rpm. In all other cases it is "high".

Terminal 61e signal is placed on the CAN/engine compartment by the instrument cluster (A1) and is therefore available to the control modules of this bus system. In addition terminal 61e is made available as a discrete signal by the instrument cluster (A1).

Networking (see figure below)

The following data is required:
- Terminal 61 generator check
The "Terminal 61" signal of the generator (G2) (generator check) is read in directly by the instrument cluster (A1)

- Engine speed
The pulse of the crankshaft position sensor (L5) is read in by the injection system control module (N3). This control module sends the message "engine speed" (in rpm) to the CAN/engine compartment.

The instrument cluster (A1) receives this data and evaluates it as described above.


NOTE: The same data is used for the generator charge indicator warning message "BATTERY/GENERATOR CHECK - FIND A WORKSHOP". This message appears in the multifunction display (A1p13) when "Terminal 61" is on "low" and the engine speed is more than 200 rpm.


The table below summarizes the relationships outlined above:







Notes on the table
Terminal 61 can assume "high" and "low" status. This status depends on the actual voltage at the Input of the instrument cluster (A1). It is "high" if this voltage is higher than 9.7 V. It changes to "low" when the voltage is drops below 9.7 V again. The specified voltage thresholds only apply for an electrical system voltage of 12 V. If the electrical system voltage is higher (e.g. 14 V) the thresholds are also higher.