Battery - Goes Dead After Vehicle Sits for Two Days
Group 61Electrical
Bulletin Number
61 05 96
Woodcliff Lake, NJ
May 1996
Product Engineering
SUBJECT:
Battery Goes Dead After Vehicle Sits For Two Days Or More
MODELS:
7 Series (E38) - vehicles produced prior to 5/95
Situation:
The battery goes dead after the vehicle sits for two or more days. The customer may notice that the transmission range selector switch remains illuminated (past the normal 16 minute period). This indicates that the General Module is not going into (or remaining in) sleep mode.
Cause:
Excessive battery draw.
Correction:
Check the battery draw. Correct any excessive (>50 milliamps) battery draw that is currently present by identifying and replacing the component causing the draw. Refer to the procedure below.
If no excessive battery draw is detected (i.e., the battery draw is less than 50 milliamps), it is possible that a defective internal voltage regulator in certain components can cause an intermittent battery draw. In this case, there are three separate possible causes for this complaint:
^ General Module with defective voltage regulator (corrected on all General Modules as of week 21 1995, with Hardware Number 06 or higher).
^ Door Module (driver's door or passenger's door) with defective voltage regulator, causing the General Module to wake up.
^ Instrument Cluster Electronics (IKE) Module with defective voltage regulator, causing the General Module to wake up.
Procedure:
1. Verify the complaint. If the battery is being drained because the GM is not going into or remaining in the sleep mode, a draw of 400 to 800 milliamps will be present after 16 minutes (when the GM should go to sleep).
Because the GM can be waking up intermittently, it will be necessary to monitor battery draw over some time, using a VOM with the capability to record average milliamp readings (e.g., Fluke 83 or 88).
The meter must be connected in series to the battery negative cable and the leads run out of the trunk, so that the meter is accessible with the trunk closed. Set the meter to record amperage ("Min Max" function). By pressing the Min Max button repeatedly, the minimum, maximum, and average readings can be called up sequentially. The Record function can be restarted by pressing and holding the Min Max key (to stop recording) and then pressing the Min Max key again to start recording new measurements.
This "restart" must be done after the General Module has gone into sleep mode to ensure that the average milliamp readings is accurate. This reading will be below 50 milliamps if the General Module is in sleep mode.
(Note:
These instructions apply to Fluke Models 83 and 88. Other makes or models may vary in their operation characteristics. Consult the operating instructions for other makes or models.
2. Once the complaint has been verified, print out the Control Module Identification pages for Central Body Electronics (ZK III) and instrument Cluster Electronics (IKE) and note the Hardware and Software Numbers for the General Module, Driver's Door Module, and Passenger's Door Module, and the Index Number of the IKE Module.
Replace any components which do not match (or exceed) the following data.
Description Hardware Number Production Date
General Module 06 or higher Week 24/95
Driver's Door Module 05 or higher Week 21/95
Passenger's Door 05 or higher Week 21/95
Module
IKE Module 07 or higher Week 5/95
(see note below) (Index Number)
Note:
An IKE with a defective voltage regulator will also exhibit a "slow clock"; i.e, the clock will lose several minutes each week.
3. To verify that the General Module is going into and remaining in sleep mode, perform a final test as follows:
Shut the doors and monitor the current draw at the battery. After approximately 16 minutes, the General Module should go into the sleep mode, resulting in a reduction of the current to less than 50 milliamps. At this point, restart the Record function (refer to step 1) and verify that the average reading does not exceed 50 milliamps.
Parts Information:
Description Part Number
General Module 61 35 8 352 057
Driver's Door Module 61 35 4 392 552
Passenger's Door Module 61 35 4 392 551
IKE Module 62 11 8 369 052
Warranty Information:
Parts and Labor are reimbursable under the terms of the BMW New Car Limited Warranty of 4 Years/50,000 miles.
Defect Code: 61 21 93 12 00
Labor Operation: 00 51 167 Measuring Battery Draw
Labor Allowance: 7 FRUs
Labor Operation: 00 51 779 Determine Production Dates of GM, IKE,
and Door Modules with DIS Tester
Labor Allowance: 1 FRU
Labor Operation: 00 51 773 Replace General Module
Labor Allowance: 4 FRUs
Labor Operation: 00 51 774 Replace Driver's Door Module
Labor Allowance: 6 FRUs
Labor Operation: 00 51 775 Replace Passenger's Door Module
Labor Allowance: 6 FRUs
Labor Operation: 00 51 776 Replace IKE Module
Labor Allowance: 3 FRUs