AR54.10-P-1030T Testing Quiescent Current Consumption

AR54.10-P-1030T Testing Quiescent Current Consumption

Shown On Model 211.0:

DANGER:
- Risk of explosion from explosive gas. Risk of poisoning and caustic burns from swallowing battery electrolyte. Risk of injury through burns to skin and eyes from battery acid or when handling damaged lead-add batteries
- No fire, sparks, naked flames or smoking.
- Wear protective gloves, acid-resistant clothing and safety glasses. Pour battery electrolyte only into suitable and appropriately marked containers.

1 Remove trunk floor covering from trunk.
2.1 Remove spare wheel cover or spare wheel recess paneling from trunk
2.2 Remove cover above battery
3 Prepare vehicle for testing

NOTE:
- Prerequisites: Vehicles without Keyless Go: Ignition switched off, ignition key removed.
- Vehicles with Keyless Go: Engine switched off, remote control key located outside of vehicle and outside of transmission range.

4 Disconnect trailer recognition unit
- With code 550 Trailer hitch

NOTE: If trailer recognition unit is connected,the quiescent current measured would be too leading to erroneous measurement.

Measuring

5 Set multimeter to highest possible current measuring range

CAUTION: To protect multimeter, when the central locking is actuated, currents of up to approx. 20 A flow.

- See "Commercially Available Tools" given below.

6 Connect multimeter between ground line (1) and battery control module ground point (N82)

NOTE: Ensure that power flow is not interrupted. To install multimeter previously bridge negative pole on battery and battery control module ground point (N82).

7 Read fault memory and erase
8 Mark vehicle so that it is easily visible

NOTE: So that test results are not incorrect due to unintentionally opening of the doors or working on the vehicle.

9 Close all doors and engine hood
10 Actuate closing wedge in trunk lid lock with trunk lid open

NOTE: Contact switch to "OFF" position, trunk light goes out.

11 Lock vehicle from outside

NOTE: Waiting time after locking vehicle, approx.10 minutes.

12 Perform quiescent power measurement

NOTE:
- A mean value of 60 mA should not be exceeded (nominal value < 40 mA).
- Cause 1: In the case of measure values between 1.2 and 2.5 A, a control module usually is keeping the "Bus" awake.
- Cause 2: In the case of measured values between 80 and 180 mA, usually one control module does not switch off thereby resulting in increased quiescent power consumption.

13.1 Separate control modules from rear SAM control module with fuse and relay module (N10/2)

NOTE: For cause 1: Wait 10 minutes, repeat measurement until "Bus" is asleep

13.2 Remove fuses one after another to locate defective control module
14 Disconnect control modules from CAN voltage distributors

NOTE:
- As an alternative to removing the fuses, it is also possible to disconnect the control module from the bus.

15 Remove multimeter, connect ground lead (1) to battery control module ground point (N82)

- Nut, ground lead to battery control module: 12 N.m

16 Install in the reverse order
17 Read fault memory and erase

Commercially Available Tools