Battery Charge/Generator Check
Message: <
Networking:
Battery charging and generator check
The message
<
of the multifunction display (A1p13) replaces the previous generator charge indicator lamp (A1e5). (This message is in category 2)
It appears, if the generator is not working properly (circuit 61), the engine speed is more than 200 rpm.
If the engine is switched OFF, there is no message.
Networking
The following CAN data is required:
- Circuit 61 generator check
The signal <
- Engine speed
The pulses from the crankshaft position sensor (L5) are read in by the injection system control module (N3). This control module sends the engine speed message (in rpm) on the CAN engine compartment.
The instrument cluster (A1) receives these messages and evaluates them as described above.
Circuit 61 (=D+) generator check
The CAN message circuit 61 can assume the states <
Preexcitation current for generator (standard wiring)
With the standard wiring the generator (G2) receives the preexcitation current via the generator charge indicator lamp (A1e5). When the ignition is ON, the preexcitation current flows from circuit 15 to ground via the lamp and the excitation winding. If the generator voltage and as a result the voltage at circuit 61 also increases above battery voltage when the engine is running, the excitation winding is supplied directly by the generator and the lamp goes out.
Preexcitation current for generator on models 215, 220
On models 215 and 220 the excitation winding is supplied with preexcitation current via a resistance which is in the wiring harness. When the ignition is ON the voltage at terminal 61 is low as the excitation winding almost Short-circuits the voltage. If the generator voltage increases above the battery voltage when the engine is running, the excitation winding is supplied by the generator. The voltage at terminal 61 increases to the generator voltage.
NOTE: This function of battery charging/generator check is closely related to the functions of bulb test and engine running recognition (circuit 61e).
Displaying indicator and warning messages via multifunction display, function
Categorizing indicator messages and warning message