Test functions

The test functions which could be called up on the on-board computer in previous series can now be called up in the instrument cluster.
System test (Test No. 2): The system test serves the purpose of testing the display unit together with its elements controlled by the instrument cluster electronics (IKE).

These elements are:

• All pointer instruments
• All LC displays with a segment test and their background lighting

Indicator and warning lamps for:

• Belt warning
• Fuel reserve
• General brake warning lamp
• Parking brake
• Left turn signal indicator
• Right turn signal indicator
• Front fog light
• Rear fog light
• High beam

Pointer instruments: During the system test, operation of the pointer instruments is diagnosed and a corresponding fault code is set in the fault code memory if an electrical fault occurs. In addition, particular care must be taken to observe whether the pointers move smoothly and continuously over their entire indication range during the first test pass. During the second pass within a system test sequence, the pointer instruments are not moved continuously and smoothly over their entire indication range. In this case, the electrical drive data is measured at various indication angles of the pointers.
Selecting test functions:
All test functions, apart from test numbers one and two, are interlocked and must be released by means of test function number nineteen.
Procedure: Press and hold the check control button (right-hand button in the instrument cluster) at terminal 15 "ON" until "Test No.: 01" appears in the text display (text field for check control messages). The corresponding test can be selected by repeatedly pressing the button. Then activate the set test by pressing the trip recorder reset button (left-hand button in the instrument cluster). If the test is a locked test (test 3 to 21), "Lock ON" will appear after the trip recorder reset button has been pressed. In this case, the checksum of the digits for the vehicle identification number must be set by repeatedly pressing the trip recorder reset button. The test must now be reselected with the CC button and confirmed with the trip recorder reset button. The tests one and two can be confirmed directly and thus selected with the trip recorder reset button.
To form checksum: Read out vehicle identification number with test 1.
Display example: "VIN: XY12345"
Cross sum example: 1+2+3+4+5 = 15
Test No.
Function
1
Identification instrument cluster electronics (IKE)
2
System test
3
SIA data
4
Current consumption values in l/100 km and l/h
5
Range consumption and current range
6
Fuel tank content values
7
Coolant temperature and engine speed
8
Current speed in km/h
9
System voltage terminal 30 in volts
10
Read out country-specific code
11
Read out units (AM/PM or mm.dd/dd.mm) etc.
12
Average speed for arrival and current arrival
13
Triggering acoustic signals
14
Read out of error bytes (self-diagnosis)
15
Display of I/O port statuses
16
free
17
free
18
free
19
Locking and Unlocking Test Functions
20
Entry of a correction factor for average consumption
21
Reset IKE (software reset)

Test function 20 Correction factor for the “average fuel consumption function”.
Test function 20 facilitates setting of the correction factor. The adjustment range of the correction factor is defined from 0750 to 1250. The factor must be set to 1000 (factory setting) in order to carry out a correction otherwise it will not be possible to calculate a new factor with the formula. When the factor is set to 1000, a new correction factor is derived from the actual consumption in litres per 100 km divided by the displayed consumption in litres per 100 km multiplied by 1000. If other units of measure are displayed, i.e. miles, litre or miles per gallon and kilometres per litre these units of measure must be converted into litres per 100 km for the purpose of calculating the correction factor. This new factor can be changed in test function 20 with the aid of the trip recorder reset button.
To select test function 20: Press and hold the check control button (right-hand button in the instrument cluster) at terminal 15 "ON" until "Test No.: 01" appears in the text display (text field for check control messages). Test 20 can be selected by repeatedly pressing the button. Then activate the test selected by pressing the trip recorder reset button (left-hand button in the instrument cluster).
Test function 20 is a locked test. Once "Lock ON" is indicated after triggering the test function 20 with the trip recorder reset button the cross sum of the digits of the vehicle identification number must be set by repeatedly pressing the trip recorder reset button. The test must now be reselected with the CC button and confirmed with the trip recorder reset button.
The units decimal position can be set backwards (0-9) by briefly pressing the trip recorder reset button (left-hand button in instrument cluster). The tens, hundreds and thousands decimal positions are set automatically backwards by permanently pressing the button. The correction factor remains in the valid range from 750 to 1250. The set correction factor is retained after releasing the button.