Battery charge/alternator monitoring function - GF54.30-P-3027S
Model 215, 220
Warning message in multifunction display
Networking of components
Battery charge/alternator check, valid up to 31.8.02:
The message "BATTERY/ALTERNATOR CHECK" "VISIT WORKSHOP!"
which appears in the multifunction display (A1p13) replaces the previously used alternator charge indicator/warning lamp (this message is a Category 2 message). It appears if the alternator is not functioning correctly "Term. 61" and the engine speed exceeds 200 rpm.
Battery charge/alternator check, valid as of 01.9.02:
The message "BATTERY/ALTERNATOR"
"VISIT WORKSHOP!"
which appears in the multifunction display (A1p13) replaces the previously used alternator charge indicator/warning lamp (this message has Class 2 priority 2A).
It appears if the alternator is not functioning correctly "Term. 61" and the engine speed exceeds 200 rpm.
Networking:
The following CAN data is required:
"Term. 61" alternator check The "Term. 61 (= D+)" signal from the alternator (G2) is read in by the right front SAM control unit (N10/7). The right front SAM control unit (N10/7) then transfers the message "Term. 61 High" (voltage at Term. 61 > 9 V) or "Term. 61 Low" (alternator not functioning correctly) to the interior compartment CAN.
Engine speed:
The pulses from the crankshaft position sensor (L5) are read in by the motor electronics control unit (N3/10) or the CDI control unit (N3/9). This control unit transfers the message "engine speed" (in rpm) to the engine compartment CAN.
The instrument cluster (A1) receives these messages and evaluates them as described above.
Terminal 61 (= D+) alternator check
The CAN message "Terminal 61" can assume the states "High" and "Low". This status depends on the actual voltage at the input of the right front SAM control unit (N10/7).
It becomes "High" when this voltage exceeds 9 V. It is "low" when the voltage again drops below 4.5 volts.
Excitation current for the alternator
The excitation winding is supplied with the pre-excitation current via a resistor located in the wiring harness. When the ignition is ON, the voltage at "Term. 61" is low, as the excitation winding virtually short circuits the voltage. If, when the engine is running, the alternator voltage rises above the battery voltage, the excitation winding is supplied with current by the alternator. The voltage at "Terminal 61" increases to the alternator voltage.
This battery charge/alternator check function is closely associated with the indicator lamp test and engine running detection functions ("Term. 61e").
| Instrument cluster (IC), location / task | GF54.30-P-3039S |