Battery Checking, Vehicles with a Battery Monitoring Control Module or Energy Management Control Module
Battery Checking, Vehicles with a Battery Monitoring Control Module or Energy Management Control Module
=> [ Battery Check using Diagnostic Systems VAS 5051B, VAS 5052 and VAS 5053 ]
=> [ Battery Test via Current Draw ]
=> [ Measuring No Load Voltage, Transport Mode not Active ]
=> [ Measuring No Load Voltage, Transport Mode Active ]
• In certain models the following is responsible for monitoring the electrical system: energy management control module (J644) or battery monitoring control module (J367) in connection with the data bus on board diagnostic interface (J533); allocation, refer to. The battery test for these vehicles is performed during "Guided Fault Finding".
• If the battery test is not possible with "Guided Fault Finding" due to a partially or exhaustively discharged battery, the battery can be quickly evaluated with the help of the "battery test via current draw".
• Maintenance free batteries must not be opened. Otherwise, the warranty is voided.
Battery Check using Diagnostic Systems VAS 5051B, VAS 5052 and VAS 5053
Special tools, testers and auxiliary items required
• For example, Vehicle Diagnosis, Testing and Information System (VAS 5051B) with Diagnostic Cable
Procedure
• No charging unit must be connected when checking the battery, and the engine must not be running.
• The battery temperature must be at least -10 °C (14 °F).
• Diagnostic system temperature must be between 5 and 45 °C (41 and 113 °F).
- Connect the (VAS 5051B). Refer to => [ VAS 5051B, Connecting ] VAS 5051B, Connecting.
• If a malfunction indication is displayed, refer to the (VAS 5051B) operating instructions.
- Press the Guided Functions button in the selection.
Display on (VAS 5051B):
- Enter vehicle identification number by selecting - A - and the appropriate text line - 1 -.
- Select the function or path:
- Follow further instructions on the display of (VAS 5051B), the following can be displayed:
• Battery is OK.
• Charge battery.
• Replace battery.
After the battery check:
- Press button Go To.
- Select function "Exit".
- Turn the ignition off and disconnect the diagnostic connector.
- If necessary, charge the battery, refer to => [ Battery Charger, Charging the Battery ] Battery Charger, Charging the Battery or replace it.
• If the battery must be replaced, follow the disposal regulations. Refer to => [ Pollution risk. ] Lead Acid Battery Warnings and Safety Precautions.
Battery Test via Current Draw
By checking a battery's current draw capacity during charging, a decision can be quickly made as to whether a partially or exhaustively discharged battery, refer to => [ Exhaustively Discharged Battery ] Exhaustively Discharged Battery can be made usable again by recharging or if it must be replaced.
Special tools, testers and auxiliary items required
• Battery Charger (VAS 5095A) and
• Trigger Clamp 100A (VAS 5051B/7) or
• Battery Charger (VAS 5900) or
• Battery Charger (VAS 5903) or
• Battery Charger (VAS 5904) or
• Battery Charger (VAS 5906) or
• When charging with the (VAS 5095A), the battery current draw must be measured, for example, with the (VAS 5051B/7). The battery chargers (VAS 5900), (VAS 5903), (VAS 5904) and (VAS 5906) display the current draw on the device.
• For more information regarding the battery charger, refer to the operating instructions that came with the charger.
Procedure
• The battery temperature must be at least 10 °C (50 °F).
• The battery charger must be able to deliver at least 30 amps (A), for example as with the battery chargers (VAS 5095A), (VAS 5900), (VAS 5903), (VAS 5904) and (VAS 5906).
• Battery charger connected and turned on.
- Measure the battery charge current after 5 minutes of charging.
• Specified value: The charge current must be higher than 10% of the nominal capacity.
• Example: Charge current on a 60 Ah battery after 5 minutes of charging: greater than 6 A.
- If the target value is reached, proceed with the charging operation until the battery is fully charged.
- Then test the battery with the vehicle diagnostic tester. Refer to => [ Battery Check using Diagnostic Systems VAS 5051B, VAS 5052 and VAS 5053 ].
- If the specified value is not met, replace the battery.
• If the battery must be replaced, follow the disposal regulations. Refer to => [ Pollution risk. ] Lead Acid Battery Warnings and Safety Precautions.
Measuring No Load Voltage, Transport Mode not Active
• The no load voltage measurement should only be used to evaluate the battery condition if it is not possible to perform the battery test with the diagnostic systems (VAS 5051B), (VAS 5052), and (VAS 5053) and no transport mode is active in the battery monitoring control module (J367) or energy management control module (J644).
Special tools, testers and auxiliary items required
• Handheld Multi-Meter (V.A.G 1526D)
Procedure
- Always observe the following to ensure correct measurement:
• Battery remains installed in vehicle, battery ground (GND) cable must not be disconnected.
• Open the hood or rear lid and lock the lid lock in the "closed" position so that the luggage compartment lamp is not turned on.
• Lock the vehicle with the central locking system.
• Battery must not be loaded by electrical consumers within the next 2 hours before measurement.
• Battery must not be charged within the next 12 hours before measurement.
• The battery temperature must be at least -10 °C (14 °F).
- Perform the prep work for the no load voltage measurement.
After a waiting period of at least 2 hours:
- Connect the (V.A.G 1526D) between the battery terminal clamps or to the positive terminal "+" and ground terminal "-".
- Measure the voltage between the battery terminal clamps.
• Specified value: 12.5 volts or higher, the battery is OK.
- If the no load voltage is under 12.5 volts, the battery must be recharged. Refer to => [ Battery Charger, Charging the Battery ] Battery Charger, Charging the Battery.
- After charging for 5 minutes, the current draw must be measured again. Refer to => [ Battery Test via Current Draw ].
- If the battery no load voltage is 11.6 volts or lower, the battery is exhaustively discharged. Refer to => [ Exhaustively Discharged Battery ] Exhaustively Discharged Battery.
Measuring No Load Voltage, Transport Mode Active
• During the prescribed maintenance and service work on vehicles in storage, the charge state can be read in % (SOC = State Of Charge) in the trip odometer display when the transport mode is active. This determines whether the battery needs to be fully charged.
Procedure
The following test is only possible if the transport mode is active in the battery monitoring control module (J367) or energy management control module (J644). If the transport mode is activated later, for example, when storing used vehicles, the SOC can first be determined when "the bus is at rest".
- Open the driver door.
- Turn ignition on.
- Read the SOC in % on the trip odometer display.
• Depending on the version, "TRA" can precede the value.
• Specified value: 50% or higher, the battery charge level is OK.
- If the battery charge level is less than 50%, the battery must be fully charged. Refer to => [ Battery, Charging ] Battery, Charging.
- After charging for 5 minutes, the current draw must be measured again. Refer to => [ Battery Test via Current Draw ].
- If the battery charge level is 0%, the battery is exhaustively discharged. Refer to => [ Exhaustively Discharged Battery ] Exhaustively Discharged Battery.