Measurement of Closed-Circuit Current

NOTE: Closed-circuit current should preferably be measured using an analog ammeter (measuring instrument with gauge) or a digital multimeter with a long integration time (to filter out voltage peaks).


Before measuring the closed-circuit current, determine the vehicle equipment (M-numbers) and establish the expected closed-circuit current with the aid of the attached table.

Preparations on the vehicle
Open the front luggage compartment Using a suitable tool, close lower part of luggage compartment lock whilst keeping the luggage compartment lid open. This tool may consist of the upper part of the lock, to which a handle is screwed. Remove the ignition key and lock the vehicle with the remote control (the alarm system is then primed).

Connect measuring instrument:
To retain the radio code or PCM code, the following procedure is recommended:
1 Set the measuring instrument to the highest possible current-measuring range.
2 With two alligator clips, connect the measuring instrument to the battery ground and to the unoccupied second body ground which is always available or RHD or LHD versions.
3 Remove ground strap from the body and secure against contact with the body. The entire vehicle current now flows through the ammeter.

Measurement:
1 Select a measuring range which ensures that the pointer of the instrument is in the upper third of the scale, as far as possible. Switch over measuring range without interruption. Read off the measuring range only when 30 minutes have passed since the vehicle was locked.
2 As the closed-circuit current does not flow in a uniform manner, a tolerance must be allowed for slightly pulsating fluctuations in the displayed measured value (see note).
3 Compare the displayed measured value with the value previously determined with the aid of the equipment list. Differences of 20 % are possible due to different battery charge conditions or temperatures.
4 After measurement, first screw the ground strap back onto the body. This procedure ensures that the radio code is retained.


NOTE: If the value of the closed-circuit current is higher than the value determined in the table, the cause must be established.


The recommended troubleshooting procedure is to disconnect the fuses of terminal 30 and the relay one after the other, with the measuring instrument connected. Observe the measuring instrument while removing the fuses, in order to recognize a reduction in current. After troubleshooting, screw the ground strap back onto the body in the proper manner.


CAUTION:
Do not switch on any electrical loads (starting the engine deactivating the alarm system, and so on) during measurement.

Table Of Close-Circuit Currents: