5.1 - Convenience feature (CF) 23 - Test program - Electrical system - Testing (Part 1 of 2, test steps 1-21.2) Model 140

Test
step

Fault
code

Scope

Instrument/
Test connection

Action/
Prerequisites

Nominal value

Possible cause/Remedy

 1.0 









Power supply
Terminal 30A

N57



10    21

(A.10) (A.21)

Ignition: OFF

11-14 V

 1.1

Terminal 31A

 1.1

Terminal 30A

N57



   21

(A.21)

Ignition: OFF

11-14 V

Terminal 30A

 2.0 









Power supply
Terminal 30B

N57



62    53

(B.21) (B.12)

Ignition: OFF

11-14 V

 2.1

Terminal 31B

 2.1

Terminal 30B

N57



   53

(B.12)

Ignition: OFF

11-14 V

Terminal 30B

 3.0 

Power supply
Terminal 30E

N57



11    16

(A.11) (A.16)

Ignition: OFF

11-14 V

 3.1

Terminal 31E

Test
step

Fault
code

Scope

Instrument/
Test connection

Action/
Prerequisites

Nominal value

Possible cause/Remedy

 3.1

Terminal 30E

N57



   16

(A.16)

Ignition: OFF

11-14 V

Terminal 30E

 4.0 

Power supply,
terminal 15R

N57



10    8

(A.10) (A.8)

Steering wheel lock in position 1

11-14 V

Terminal 15R

Terminal 31A

 5.0

Front door contact switch circuit (S17/3, S17/4)

N57



10    9

(A.10) (A.9)

Remove fuse (F3-17)

Ignition: OFF

Front doors: CLOSED

Driver's door: OPEN

Passenger door: OPEN

11-14 V

<2 V

<2 V

Wiring

Left door contact switch (S17/3)
Right door contact switch (S17/4)
Control unit (N57)
EDW control unit (N26)
Pneumatic control unit (A37 or A37/1)

Wiring

 5.1

Wiring

 5.1

Test
step

Fault
code

Scope

Instrument/
Test connection

Action/
Prerequisites

Nominal value

Possible cause/Remedy

 5.1

Door contact switch
(S17/3, S17/4)

N57



10    9

(A.10) (A.9)

Ignition: OFF

Roof control unit: All switches in OFF position

Disconnect connectors from pneumatic control unit.
Disconnect connector A
from N57.
Front doors: CLOSED

11-14 V

Wiring

 5.2

 5.3

 5.2

S17/3

N57



10    9

(A.10) (A.9)

Same as  5.1

Disconnect right door contact switch (S17/4).

11-14 V

Wiring

S17/3

 5.3

S17/4

N57



10    9

(A.10) (A.9)

Same as  5.1
Disconnect left door contact switch (S17/3).

11-14 V

Wiring

S17/4

Test
step

Fault
code

Scope

Instrument/
Test connection

Action/
Prerequisites

Nominal value

Possible cause/Remedy

 6.0 

Electrical tilting/sliding roof circuit (S13/2)
Function:
Close sliding roof or tilting roof

N57



10    30

(A.10) (C.3)

S13/2: not actuated

Close sliding roof or tilting roof and hold down

<1 V

11-14 V

Sliding roof or tilting roof should close

Wiring

 6.1

 6.2

Wiring

 6.1

 6.2

M12m1

M12k1

 6.1

Switch for electrical tilting/sliding roof (S13/2)

N57



28    30

(C.1) (C.3)

Ignition: OFF

Disconnect connector C from control unit (N57).

S13/2: not actuated

S13/2 in position:
Close sliding roof

S13/2 in position:

Close tilting roof

>20 kW

<1 W

<1 W

Wiring

S13/2

Wiring

S13/2

Wiring

S13/2

Test
step

Fault
code

Scope

Instrument/
Test connection

Action/
Prerequisites

Nominal value

Possible cause/Remedy

 6.2

Switch for electric tilting/sliding roof (S13/2)
Control unit (N57)

N57



10    28

(A.10) (C.1)

Ignition: ON

11-14 V

Wiring

 6.3

 6.3

N57

N57



10    28

(A.10) (C.1)

Ignition: OFF

Disconnect connector C from tilting/sliding roof wiring harness.

Ignition: ON

11-14 V

N57

 7.0 

Electric tilting/sliding roof (S13/2) circuit
Function:
Opening sliding roof

N57



10    31

(A.10) (C.4)

Ignition: ON

S13/2: not actuated

Open sliding roof and hold button depressed.

<1 V

11-14 V

Sliding roof should open

Wiring

 7.1
 7.2

Wiring

 7.1
 7.2

Motor for tilting/sliding roof (M12m1)

Relay for tilting/sliding roof (M12k1)

Test
step

Fault
code

Scope

Instrument/
Test connection

Action/
Prerequisites

Nominal value

Possible cause/Remedy

 7.1

Switch for electric tilting/sliding roof (S13/2)

N57



28    31

(C.1) (C.4)

Ignition: OFF

Disconnect connector C from control unit (N57).

S13/2: not actuated

S13/2 in position:

for opening sliding roof

>20 kW

<1 W

Wiring

S13/2

Wiring

S13/2

 7.2

S13/2
N57

N57



10    28

(A.10) (C.1)

Ignition: ON

11-14 V

Wiring

 7.3

 7.3

N57

N57



10    28

(A.10) (C.1)

Ignition: OFF

Disconnect connector C from tilting/sliding roof wiring harness.

Ignition: ON

11-14 V

N57

Test
step

Fault
code

Scope

Instrument/
Test connection

Action/
Prerequisites

Nominal value

Possible cause/Remedy

 8.0 

Electric tilting/sliding roof (S13/2) circuit
Function:
Opening tilting roof

N57



10    29

(A.10) (C.2)

Ignition: ON

S13/2: not actuated

Open tilting roof and hold button depressed.

<1 V

11-14 V

Tilting roof should open

Wiring

 8.1

 8.2

Wiring

 8.1

 8.2

Motor for tilting/sliding roof (M12m1)

Relay for tilting/sliding roof (M12k1)

8.1

Switch for electric tilting/sliding roof (S13/2)

N57



28    29

(C.1) (C.2)

Ignition: OFF

Disconnect connector C from control unit (N57).

S13/2: not actuated

S13/2 in position:

for opening tilting roof

>20 kW

<1 W

Wiring

S13/2

Wiring

S13/2

Test
step

Fault
code

Scope

Instrument/
Test connection

Action/
Prerequisites

Nominal value

Possible cause/Remedy

 8.2

S13/2
N57

N57



10    28

(A.10) (C.1)

Ignition: ON

11-14 V

Wiring

 8.3

 8.3

N57

N57



10    28

(A.10) (C.1)

Ignition: OFF

Disconnect connector C from tilting/sliding roof wiring harness.

Ignition: ON

11-14 V

N57

 9.0

Recognition USA/ECE

N57



33    34

(D.2) (D.3)

Ignition: OFF

Disconnect connector D from control unit (N57).

Code for USA:

<1 W

Code for ECE:

>20 kW

Wiring

Wiring

Test
step

Fault
code

Scope

Instrument/
Test connection

Action/
Prerequisites

Nominal value

Possible cause/Remedy

 10.0  



Front left window (S21/1) circuit
Function: Opening

Ignition: ON

N57



10    24

(A.10) (E.3)

S21/1: not actuated

S21/1 in position:

Hold in Open position 1

Hold in Open position 2

9-14 V

<1 V

<1 V

Wiring

 10.1

Control unit (N57)

Wiring

 10.1

Wiring

 10.1

 10.1

Switch for front left window (S21/1)

N57



10    24

(A.10) (E.3)

Ignition: OFF

Disconnect connector E from N57.

S21/1: not actuated

S21/1 in position:

Hold in Open position 1

Hold in Open position 2

>20 kW

<2 W

<2 W

Wiring

S21/1

Wiring

S21/1

Wiring

S21/1

Test
step

Fault
code

Scope

Instrument/
Test connection

Action/
Prerequisites

Nominal value

Possible cause/Remedy

 11.0 



Front left window circuit (S21/1)
Function: Closing

Ignition: ON

N57



10    26

(A.10) (E.5)

S21/1: not actuated

S21/1 in position:

Hold in Close position 1

Hold in Close position 2

9-14 V

<1 V

<1 V

Wiring

 11.1

Control unit (N57)

Wiring

 11.1

Wiring

 11.1

 11.1

Switch for left front window (S21/1)

N57



10    26

(A.10) (E.5)

Ignition: OFF

Disconnect connector E
from N57.

S21/1: not actuated

S21/1 in position:

Hold in Close position 1

Hold in Close position 2

>20 kW

<2 W

<2 W

Wiring

S21/1

Wiring

S21/1

Wiring

S21/1

Test
step

Fault
code

Scope

Instrument/
Test connection

Action/
Prerequisites

Nominal value

Possible cause/Remedy

 12.0  



Front left window circuit (S21/1)
Function: Automatic mode

Ignition: ON

N57



10    27

(A.10) (E.6)

S21/1: not actuated

S21/1 in position:

Hold in Open position 1

Hold in Open position 2

9-14 V

9-14 V

<1 V

Wiring

 12.1

Control unit (N57)

Wiring

 12.1

N57

Wiring

 12.1

 12.1

Switch for left front window (S21/1)

N57



10    27

(A.10) (E.6)

Ignition: OFF

Disconnect connector E
from N57.

S21/1: not actuated

S21/1 in position:

Hold in Open position 1

Hold in Open position 2

>20 kW

>20 kW

<2 W

Wiring

S21/1

Wiring

S21/1

Wiring

S21/1

Test
step

Fault
code

Scope

Instrument/
Test connection

Action/
Prerequisites

Nominal value

Possible cause/Remedy

 13.0 



Front left window circuit (S21/1)
Function: Automatic mode

Ignition: ON

N57



10    27

(A.10) (E.6)

S21/1: not actuated

S21/1 in position:

Hold in Close position 1

Hold in Close position 2

9-14 V

9-14 V

<1 V

Wiring

 13.1

Control unit (N57)

Wiring

 13.1

N57

Wiring

 13.1

 13.1

Switch for left front window (S21/1)

N57



10    27

(A.10) (E.6)

Ignition: OFF

Disconnect connector E
from N57.

S21/1: not actuated

S21/1 in position:

Hold in Close position 1

Hold in Close position 2

>20 kW

>20 kW

<2 W

Wiring

S21/1

Wiring

S21/1

Wiring

S21/1

Test
step

Fault
code

Scope

Instrument/
Test connection

Action/
Prerequisites

Nominal value

Possible cause/Remedy

 14.0 



Front right window (S21/2) circuit
Function: Opening

Ignition: ON

N57



10   38

(A.10) (F.3)

S21/2: not actuated

S21/2 in position:

Hold in Open position 1

Hold in Open position 2

9-14 V

<1 V

<1 V

Wiring

 14.1

Control unit (N57)

Wiring

 14.1

Wiring

 14.1

 14.1

Switch for front right window (S21/2)

N57



10   38

(A.10) (F.3)

Ignition: OFF

Disconnect connector F
from N57.

S21/2: not actuated

S21/2 in position:

Hold in Open position 1

Hold in Open position 2

>20 kW

<2 W

<2 W

Wiring

S21/2

Wiring

S21/2

Wiring

S21/2

Test
step

Fault
code

Scope

Instrument/
Test connection

Action/
Prerequisites

Nominal value

Possible cause/Remedy

 15.0 



Front right window circuit (S21/2)
Function: Closing

Ignition: ON

N57



10    36

(A.10) (F.1)

S21/2: not actuated

S21/2 in position:

Hold in Close position 1

Hold in Close position 2

9-14 V

<1 V

<1 V

Wiring

 15.1

Control unit (N57)

Wiring

 15.1

Wiring

 15.1

 15.1

Switch for right front window (S21/2)

N57



10    36

(A.10) (F.1)

Ignition: OFF

Disconnect connector F
from N57.

S21/2: not actuated

S21/2 in position:

Hold in Close position 1

Hold in Close position 2

>20 kW

<2 W

<2 W

Wiring

S21/2

Wiring

S21/2

Wiring

S21/2

Test
step

Fault
code

Scope

Instrument/
Test connection

Action/
Prerequisites

Nominal value

Possible cause/Remedy

 16.0 



Front right window circuit (S21/2)
Function: Automatic mode

Ignition: ON

N57



10    37

(A.10) (F.2)

S21/2: not actuated

S21/2 in position:

Hold in Open position 1

Hold in Open position 2

9-14 V

9-14 V

<1 V

Wiring

 16.1

Control unit (N57)

Wiring

 16.1

N57

Wiring

 16.1

 16.1

Switch for right front window (S21/2)

N57



10    37

(A.10) (F.2)

Ignition: OFF

Disconnect connector F
from N57.

S21/2: not actuated

S21/2 in position:

Hold in Open position 1

Hold in Open position 2

>20 kW

>20 kW

<2 W

Wiring

S21/2

Wiring

S21/2

Wiring

S21/2

Test
step

Fault
code

Scope

Instrument/
Test connection

Action/
Prerequisites

Nominal value

Possible cause/Remedy

 17.0 



Front right window circuit (S21/2)
Function: Automatic mode

Ignition: ON

N57



10   37

(A.10) (F.2)

S21/2: not actuated

S21/2 in position:

Hold in Close position 1

Hold in Close position 2

9-14 V

9-14 V

<1 V

Wiring

 17.1

Control unit (N57)

Wiring

 17.1

N57

Wiring

 17.1

 17.1

Switch for right front window (S21/2)

N57



10   37

(A.10) (F.2)

Ignition: OFF

Disconnect connector F
from N57.

S21/2: not actuated

S21/2 in position:

Hold in Close position 1

Hold in Close position 2

>20 kW

>20 kW

<2 W

Wiring

S21/2

Wiring

S21/2

Wiring

S21/2

Test
step

Fault
code

Scope

Instrument/
Test connection

Action/
Prerequisites

Nominal value

Possible cause/Remedy

 18.0 



Left rear window circuit (S21/3, S21/5)
Function: Opening

N57



10    39

(A.10) (F.4)

Ignition: ON

Safety switch for rear power windows (S21/7) in position: unlocked

S21/3 and S21/5:

not actuated

S21/3 in position:

Hold in Open position 1

Hold in Open position 2

S21/5 in position:

Hold in Open position 1

Hold in Open position 2

9-14 V

<1 V

<1 V

<1 V

<1 V

Wiring

 18.1

 18.2

Control unit (N57)

Wiring

 18.1

 30.0

Wiring

 18.1

Wiring

 18.2

Wiring

 18.2

Test
step

Fault
code

Scope

Instrument/
Test connection

Action/
Prerequisites

Nominal value

Possible cause/Remedy

 18.1

Switch for left rear window (S21/3)

N57



10    39

(A.10) (F.4)

Ignition: OFF

Disconnect connector F
from N57.

S21/3 and S21/5 in:

not actuated

S21/3 in position:

Hold in Open position 1

Hold in Open position 2

>20 kW

<3 W

<3 W

Wiring

S21/3

S21/5

Wiring

S21/3

Wiring

S21/3

Test
step

Fault
code

Scope

Instrument/
Test connection

Action/
Prerequisites

Nominal value

Possible cause/Remedy

 18.2

Switch for left rear window (S21/5, console)

N57



10    39

(A.10) (F.4) X35/3

6    7

Ignition: OFF

Disconnect connector F
from N57.
Disconnect left rear door separation point (X35/3).

S21/5: not actuated

S21/5 in position:

Hold in Open position 1

Hold in Open position 2

>20 kW

<2 W

<2 W

Wiring

S21/5

Wiring

S21/5

Wiring

S21/5

Test
step

Fault
code

Scope

Instrument/
Test connection

Action/
Prerequisites

Nominal value

Possible cause/Remedy

 19.0 



Left rear window circuit (S21/3, S21/5)
Function: Closing

N57



10    41

(A.10) (F.6)

Ignition: ON

Safety switch for rear power windows (S21/7) in position: unlocked

S21/3 and S21/5:

not actuated

S21/3 in position:

Hold in Close position 1

Hold in Close position 2

S21/5 in position:

Hold in Close position 1

Hold in Close position 2

9-14 V

<1 V

<1 V

<1 V

<1 V

Wiring

 19.1

 19.2

Wiring

 19.1

 26.0

Wiring

 19.1

Wiring

 19.2

Wiring

 19.2

Test
step

Fault
code

Scope

Instrument/
Test connection

Action/
Prerequisites

Nominal value

Possible cause/Remedy

 19.1

Switch for left rear window (S21/3)

N57



10    41

(A.10) (F.6)

Ignition: OFF

Disconnect connector F from control unit (N57).

S21/3 and S21/5:

not actuated

S21/3 in position:

Hold in Close position 1

Hold in Close position 2

>20 kW

<3 W

<3 W

Wiring

S21/3

S21/5

Wiring

S21/3

Wiring

S21/3

Test
step

Fault
code

Scope

Instrument/
Test connection

Action/
Prerequisites

Nominal value

Possible cause/Remedy

 19.2

Switch for left rear window (S21/5, console)

N57



10    41

(A.10) (F.6)

Ignition: OFF

Disconnect connector F
from N57.
Disconnect left rear door separation point (X35/3).

S21/5: not actuated

S21/5 in position:

Hold in Close position 1

Hold in Close position 2

>20 kW

<2 W

<2 W

Wiring

S21/5

Wiring

S21/5

Wiring

S21/5

Test
step

Fault
code

Scope

Instrument/
Test connection

Action/
Prerequisites

Nominal value

Possible cause/Remedy

 20.0 



Left rear window circuit (S21/3, S21/5)
Function: Automatic mode

N57



10    40

(A.10) (F.5)

Ignition: ON

Safety switch for rear power windows (S21/7) in position: unlocked

S21/3 and S21/5: not actuated

S21/3 in position:

Hold in Open position 1

Hold in Open position 2

S21/5 in position:

Hold in Open position 1

Hold in Open position 2

9-14 V

9-14 V

<1 V

9-14 V

<1 V

Wiring

 20.1

 20.2

Control unit (N57)

Wiring

 20.1

N57

Wiring

 20.1

 26.0

Wiring

 20.2

N57

Wiring

 20.2

Test
step

Fault
code

Scope

Instrument/
Test connection

Action/
Prerequisites

Nominal value

Possible cause/Remedy

 20.1

Switch for left rear window (S21/3)

N57



10    40

(A.10) (F.5)

Ignition: OFF

Disconnect connector F
from N57.

S21/3 und S21/5: not actuated

S21/3 in position:

Hold in Open position 1

Hold in Open position 2

>20 kW

>20 kW

<3 W

Wiring

S21/3

S21/5

Wiring

S21/3

Wiring

S21/3

Test
step

Fault
code

Scope

Instrument/
Test connection

Action/
Prerequisites

Nominal value

Possible cause/Remedy

 20.2

Switch for left rear window (S21/5, console)

N57



10    40

(A.10) (F.5)

Ignition: OFF

Disconnect connector F
from N57.
Disconnect left rear door separation point (X35/3).

S21/5: not actuated

S21/5 in position:

Hold in Open position 1

Hold in Open position 2

>20 kW

>20 kW

<2 W

Wiring

S21/5

Wiring

S21/5

Wiring

S21/5

Test
step

Fault
code

Scope

Instrument/
Test connection

Action/
Prerequisites

Nominal value

Possible cause/Remedy

 21.0 



Left rear window circuit (S21/3, S21/5)
Function: Automatic mode

N57



10    40

(A.10) (F.5)

Ignition: ON

Safety switch for rear power windows (S21/7) in position: unlocked

S21/3 and S21/5: not actuated

S21/3 in position:

Hold in Close position 1

Hold in Close position 2

S21/5 in position:

Hold in Close position 1

Hold in Close position 2

9-14 V

9-14 V

<1 V

9-14 V

<1 V

Wiring

 21.1

 21.2

Control unit (N57)

Wiring

 21.1

N57

Wiring

 21.1

Wiring

 21.2

N57

Wiring

 21.2

Test
step

Fault
code

Scope

Instrument/
Test connection

Action/
Prerequisites

Nominal value

Possible cause/Remedy

 21.1

Switch for left rear window (S21/3)

N57



10    40

(A.10) (F.5)

Ignition: OFF

Disconnect connector F
from N57.

S21/3 and S21/5:

not actuated

S21/3 in position:

Hold in Close position 1

Hold in Close position 2

>20 kW

>20 kW

<3 W

Wiring

S21/3

S21/5

Wiring

S21/3

Wiring

S21/3

Test
step

Fault
code

Scope

Instrument/
Test connection

Action/
Prerequisites

Nominal value

Possible cause/Remedy

 21.2

Switch for left rear window (S21/5, console)

N57



10    40

(A.10) (F.5)

Ignition: OFF

Disconnect connector F
from N57.
Disconnect left rear door separation point (X35/3).

S21/5: not actuated

S21/5 in position:

Hold in Close position 1

Hold in Close position 2

>20 kW

>20 kW

<2 W

Wiring

S21/5

Wiring

S21/5

Wiring

S21/5