Vehicle idle function - GF54.10-P-2000CW
MODEL 204.0/2 up to Model Year 2008
Function requirement
- Transition from circuit 15R to circuit 15C
Vehicle idle state (quiescent current management) in general
The quiescent current management integrated into the rear SAM control unit with fuse and relay module (N10/2) should help to guarantee the vehicle's starting capability. This extends the service life of the on-board electrical system battery (G1), to this end, circuit 30g consumers are disconnected by the quiescent current cutout relay (F32k2) from the power supply.
In addition to this, the quiescent current management data is made available over STAR DIAGNOSIS.
The vehicle idle state function is made up of the following functions:
- Request to switch off consumer
- Switch off consumer
- Switch on consumer
Request to switch off consumer function sequence
During transition from circuit 15R to circuit 15C the timer starts up for a waiting time of t = 6 h until quiescent current cutoff. If, during this waiting time, the battery sensor (B95) signals a voltage lower than the voltage limit of U < 11.8 V, then the quiescent current cutout relay is opened prematurely.
At t = 5 min before the quiescent current cutout relay is opened, a cutout signal is applied in advance by the rear SAM control unit to the interior CAN and forwarded over the front SAM control unit with fuse and relay module (N10/1) to the chassis CAN. The cutout signal is relevant for all connected control units that are also powered over circuit 30g.
If during signal transmission the interior CAN and the chassis CAN are in sleep mode, the control units are activated.
The relevant control units prepare themselves for the power supply cutout. Within this period of t = 5 min the control units are set to the "power-down mode" (decentralized power management).
Switch off consumer function sequence
Once the cutout time is reached the quiescent current management opens the quiescent current cutout relay, if a wake-up signal is not received in the meantime. The status of the quiescent current cutout relay is sent to the interior CAN and over the front SAM control unit to the chassis CAN.
Switch on consumer function sequence
If a system is activated, the quiescent current management closes the quiescent current cutout relay and the functions are all available again. After a shortened waiting time of t = 25 min the quiescent current cutout relay is opened again.
After a wake-up signal to the rear SAM control unit, the quiescent current management closes the quiescent current cutout relay and signals on the interior CAN and over the front SAM control unit to the chassis CAN that the wake-up conditions are enabled again for the control units.
When the quiescent current cutout relay is closed the circuit 30g consumers are activated again.
The following list of conditions authorizes closure of the quiescent current cutout relay:
- Circuit 15R ON:
The quiescent current cutout relay is closed and the timer control stopped. The quiescent current cutout relay remains closed as long as circuit 15R is still applied.
- Unlock/open door or change in status of circuit 15C:
The quiescent current cutout relay is closed and the timer control reset by t = 25 min.
- Hazard warning system, standing light or parking lights on or signals from special-purpose vehicles:
The quiescent current cutout relay is closed and the timer control stopped. If the function remains active, the timer control is reset by t = 25 min. The quiescent current cutout relay is kept closed.
- Anti-theft alarm system (ATA [EDW]) activated (with code (551) Anti-theft alarm system (ATA [EDW])):
The quiescent current cutout relay is closed and the timer control is stopped.
| On-board computer control electrical function diagram | PE54.10-P-2052-99FAA | ||
| Transmitter key, component description | A8/1 | GF80.57-P-6010CW | |
| Battery sensor component description | B95 | GF54.10-P-2100CW | |
| Front SAM control unit with fuse and relay module, component description | N10/1 | GF54.21-P-6070CW | |
| Rear SAM control unit with fuse and relay module, component description | N10/2 | GF54.21-P-6030CW | |
| Electronic ignition lock control unit, component description | N73 | GF80.57-P-6001CW |