Electrical System - Parasitic Draw Measurement
SI B61 08 00
General Electrical Systems
May 2012
Technical Service
This Service Information bulletin supersedes SI B61 08 00 dated December 2010.
[NEW] designates changes to this revision
SUBJECT
Closed-circuit Current Measurement
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MODEL
All
SITUATION
Increased closed-circuit currents may occur permanently or intermittently and cause the battery to discharge prematurely. The increase in
closed-circuit current may be caused by a faulty control unit, or by the installation of a non-approved accessory.
In a situation where a vehicle has broken down due to a discharged battery, for diagnostic purposes it is important not to disconnect the battery. This
is because a control unit will be reset if the battery is disconnected. Following a reset, the faulty control unit may start functioning correctly again,
making accurate diagnosis impossible.
[NEW] To correctly measure closed-circuit current, the 50-amp clip-on probe (previously used with the MIB) or the 100-amp clip-on probe can now
be used in conjunction with the IMIB (Integrated Measurement Interface Box) to properly diagnosis closed-circuit current problems over an
extended period of time. Connect the amp clip-on probe directly to the IMIB Measurement input 3 (green socket). Refer to SI B04 35 09 for
information about the IMIB.
WARRANTY INFORMATION
Not applicable
Procedure
PROCEDURE
1. [NEW] It is very important that any "Power management" faults stored be diagnosed and corrected, and the "Energy Diagnosis" test plan
carried out before the following procedure is performed. Only perform this procedure if closed-circuit current violations are listed in the "Most
Likely Cause" list.
2. [NEW] Check and test the battery using the BMW Battery Tester. Refer to SI B 04 25 02 for information about the BMW Battery. Refer to SI
B61 02 11 for vehicles equipped with advanced onboard battery diagnostics that do not require the BMW Battery Tester. If necessary,
recharge or replace the battery.
3. If the battery is installed in the trunk, open the trunk and turn the lock to the locked position, using a screwdriver or similar (simulates the
trunk lid being closed). The hood must be closed. If the battery is installed in the engine compartment, open the hood and pull the front lid
contact switch fully up, and lock in this position (workshop position, simulates the front lid being closed). The trunk must be closed.
4. With the exception of the trunk/hood above, all other doors/lids must be closed.
5. In order to simulate normal closed-circuit conditions:
^ Turn the ignition on and activate all electrical consumers, including any accessories. Turn the ignition off. In some cases, a drive cycle
may need to be carried out in order to duplicate a closed-circuit current problem.
^ Open and close the driver's door (simulates somebody getting out).
^ Lock the car, arming the DWA if this is installed.
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6. In general, closed-circuit current consistently over 50mA must be investigated. Depending on the vehicle's equipment, closed-circuit current
by vehicle model is approximately as shown above.
7. If the nominal milliamp reading is not achieved after the appropriate time, refer to the attached troubleshooting charts. On 2005 MY vehicles
equipped with BMW ASSIST, there are additional current fluctuations as high as 500ma that last for approximately 2 minutes. The
fluctuations occur every 15 minutes for up to 14 hours after key off. This is considered normal operation of the TCU, and should not be
considered a fault. This also applies to 2005 TCUs that are installed into earlier production vehicles as replacement parts.
^ E60, E63, E64 Closed-Circuit Current Troubleshooting E6x up to 9/05 production
^ E60, E61, E63, E64 Closed-Circuit Troubleshooting E6x from 9/05 production
^ E65, E66 Closed-Circuit Current Troubleshooting up to 3/04 production
^ E65, E66 Closed-Circuit Current Troubleshooting from 3/04 production
^ Normal closed-circuit current values for E65, E70, E60, E61, E63, and E64
CLOSED-CIRCUIT CURRENT MEASUREMENT WITH THE IMIB
Note:
This technique with an IMIB is particularly suitable for extended measurements, and provides a graphical readout of recorded
measurements over time. It is recommended for situations where the use of a multimeter provided insufficient information for problem
diagnosis.
1. The IMIB can be accessed from any ISID within the workshop.
2. Select "Activities".
3. Select "Measuring devices".
4. Select from the "Level 1" column, "Measuring devices", and then "OK".
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5. From the "Connection manager" screen, select the free IMIB and "Set up connection".
6. The "Measures devices" screen opens on the "Multimeter" tab.
7. Select the "Oscilloscope" tab.
8. Highlight the "CH1" tab to activate channel 1.
9. Under channel 1, "Source", scroll with the arrows to select "Clip-on probe 50A".
10. Make sure that clip-on probe is not connected to the battery cable, and acknowledge the pop-up message with "OK".
11. Change the "A/Div" setting to "1A".
12. Under the "Time" selection box, change the "Time/Div" setting based on the number of measurements needed (5 ms to 200 s). The longer
times should be selected when performing the measurement over an extended period.
13. Select "CH 1" under "Cursor" to monitor the actual readings.
14. Select "Record" if performing long term measurements.
15. After performing the measurement, select "Record" again; the display will change to "Compress" and display the recorded data on the 1
screen.
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