AR54.10-P-1030-06P Determining Unfused Components With Excessive Quiescent Current Consumption

AR54.10-P-1030-06P Determining Unfused Components With Excessive Quiescent Current Consumption

Commercially Available Tools:

1. Determine unfused components according to wiring diagram.
2. Remove fuse 9 (for overhead control panel control module N70) from rear SAM control module with fuse and relay module (N10/2) and do not replace for the time being. This ensures that the in-car air temperature sensor fan motor (N70m1) is not supplied with current.
See "Wiring Diagrams" for models 203, 209, 463. Note run-on time for control modules: Models 203, 209, 463 approx. four minutes.

3. Read off total quiescent current on the multimeter connected to the battery and note value.
4. Disconnect coupling or connector on potential quiescent current consumer and tie back to prevent unintentional contact.
5. Read off actual total quiescent current on multimeter and note the difference with respect to the reading from step 3. If the total quiescent current decreases by more than 0.02 A (20 mA) after disconnection of a component, then this component is probably defective.
6. Reconnect coupling or connector to the (new, if replaced) component.
7. Repeat test on all quiescent current consumers as described above.
8. This test step is performed in the event that several unfused current paths exhibit a (slightly) excessive quiescent current consumption: Add the noted differences.
^ If the sum total of the differences then the unfused ≤ 35 mA, current paths are presumable OK:
^ If the sum total of the differences > 35 mA, check components of unfused current paths with the highest quiescent currents. Unfortunately no test values can be quoted for this, as they vary according to the path concerned and the calculated total current.

9. To check, re-test quiescent current.