12 00... Instructions For Disconnecting And Connecting Battery
Observe safety instructions for handling vehicle battery. Refer to 61 00... SAFETY INSTRUCTIONS FOR HANDLING VEHICLE BATTERY .
Before Disconnecting Battery:
Switch off ignition.
- There is a danger of mixing up battery leads: If the battery positive and negative leads are the same color and you are in doubt, follow the polarity to the battery, then mark and cover the leads.
- On vehicles with radio code: After disconnecting the battery, the radio code must be re-entered. Therefore obtain the radio code card from the customer beforehand. Note stored stations and restore them after connecting the battery.
- Stored settings of the on-board computer and clock will also be lost.
- All available central keys must be recoded for cars with first generation infrared transmitter locking systems.
General Notes On Disconnecting Battery:
- Do not disconnect battery leads and leads from alternator and starter motor while engine is running.
- Cars with IBS on battery negative terminal:
Do not under any circumstances pull/lever off pole shoes by force.
Do not under any circumstances release socket-head cap screw of IBS.
- Detach terminal of battery negative lead from car battery and second battery if fitted. Cover battery negative terminal(s) and secure. Refer to 61 20 900 DISCONNECTING AND CONNECTING BATTERY NEGATIVE LEAD .
- When work is carried out on the electrical system, faults may be caused in the fault memories of some control units when the battery is connected.
- When fitting terminal for battery negative lead: tightening torque, refer to 61 21 1AZ in GENERAL ELECTRICAL SYSTEM - TIGHTENING TORQUES .
After Connecting Battery:
Likewise, individual settings are lost and must be activated.
Example:
- Activate sliding sunroof. Refer to 54 0... NOTES ON STEEL AND GLASS SLIDE/TILT SUNROOFS (INITIALIZATION/NORMALIZATION/LEARNING OF CHARACTERISTIC CURVE) .
- Vehicles with AFS only: Activate steering angle.
- If necessary, activate power windows.67 62... NOTES ON INITIALIZING POWER WINDOW .
- If necessary, activate mirror with compass.
For further information and instructions on vehicle specific activation, please refer to the point PROCEDURE FOR INITIALIZATION under the document type "SI INSTRUCTIONS" from the IDC.
Vehicles With A Two-Battery System
Starter And Equipment Batteries:
A two-battery system has a starter battery circuit and an equipment battery circuit. A secondary control unit monitors both battery circuits. Depending on the situation, the battery circuits are connected to or isolated from the secondary control unit via an isolating relay.
Two AGM batteries are used as a storage battery.
Receiving/Giving Starting Assistance Via Jump Start Terminal:
The engine can be jump-started with an external voltage supply via the jump start terminal on the right side of the engine compartment.
Giving starting assistance via the jump start terminal is thus limited by the capacity of the starter battery when the engine hood/bonnet is open.
Charging Starter And Equipment Batteries Via Jump Start Terminal:
The starter battery is charged as a matter of priority with a charger connected to the jump start terminal. The voltage at the starter battery is the decisive factor in determining whether the equipment battery is also included in the charging operation. The secondary control unit automatically detects a charging operation at a charging voltage at the starter battery of >/= 13.5 V. The isolating relay is closed and thus the equipment battery is connected in parallel. Both batteries are now charged.
Prerequisite:
- Terminal 61 inactive.
- Terminal 15 inactive.
If terminal 15 becomes "active" during the charging operation, the isolating relay is opened immediately and again only the starter battery is charged.
Trickle Charging:
Increased closed-circuit current consumption can be compensated with the aid of the battery trickle charger (special tool 61 2 410) via the jump start terminal.