Determining circuit with excessive quiescent current consumption - AR54.10-P-1030-04P

Fig 1: Identifying Electrical Connection Set (201 589 00 99 00)

Fig 2: Identifying Quiescent-Current Test Adapter 1 (140 589 12 21 00)

Fig 3: Identifying Quiescent Current Test Adapter 2 (140 589 13 21 00)

Fig 4: Identifying Test Cable, Second Multimeter And Quiescent Current Test Adapter

1. Remove covers on front SAM control module with fuse and relay module (N10/1), rear SAM control module with fuse and relay module (N10/2) and interior fuse box (F34).
2. In vehicles with ATA, lock engine hood catch with a screwdriver.
3. Lock the vehicle.
4. 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 temperature sensor fan motor (N70m1) is not supplied with current.

   Observe Up-to-date Information (AI) bulletin!

   First check the circuits of the components listed in the Up-to-date Information bulletin.

5. Remove fuse of relevant component or current path.

   Only remove the ATA fuse when the vehicle is unlocked (alarm signal).

6. Connect test cable (6) and quiescent current test adapter (13) to a second multimeter (12) using electrical connection set (measuring range in amperes).
7. Instead of the fuse, connect quiescent current test adapter (13) with the second multimeter and read off the quiescent current.
   • If quiescent current > 20 mA, wait four minutes and read off quiescent current again.
   • If quiescent current > 20 mA, determine fused components with excessive quiescent current consumption!
   • If quiescent current ≤ 20 mA, the fused current path is OK. Note quiescent current and fuse number.
8. Then check quiescent current consumption of the remaining current paths according to test step  7.
9. Instead of fuse 9 (for overhead control panel control module (N70)) in the rear SAM control module with fuse and relay module (N10/2), connect quiescent current test adapter (13) with the second multimeter and read off the quiescent current.

   If quiescent current > 20 mA, wait 30 minutes and read off quiescent current again.

   • If quiescent current > 20 mA, check overhead control panel control module (N70).
   • If quiescent current ≤ 20 mA, the fused current path is presumably OK. Note quiescent current and fuse number.
10. This test step is performed in the event that several fused current paths exhibit a (slightly) excessive quiescent current consumption:

    Add the noted quiescent currents.

    • If the calculated quiescent current is ≤ 35 mA, the fused current paths are presumably OK: Determine unfused components with excessive quiescent current consumption!

      If the calculated quiescent current is > 35 mA, check components of fused 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.

After inserting the fuse or the quiescent current test adapter, the connected control modules may exhibit a higher quiescent current for up to four minutes.