Test readings, control module connections
| Test readings, control module connections |
| Scope |
Values and instructions for measuring voltages on the control modules will be found under the headings in the respective sections.
| Remember |
| • |
Note the test conditions and use common sense when assessing the test result.
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| • |
The measuring values shown are with the ignition ON, unless otherwise stated.
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| • |
First check that the control module has a power supply and is grounded.
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| • |
Then check all sensor inputs and signals from other systems.
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| • |
Lastly, check the control module outputs. Remember that the measured values do not tell us whether or not the control module is functioning.
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| • |
If any reading is not OK, consult the wiring diagram to trace the leads, connectors or components which should be checked more thoroughly.
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| • |
The specified test readings refer to those obtained with a calibrated Fluke 88/97.
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| • |
Test readings in %(+) and ms(+) show the pulse ratio and pulse duration of the signal. A test instrument capable of giving pulse ratio and pulse duration readings must be used. The sign indicates a positive trigger pulse, TRIG+.
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> = greater than ; < = less than ; ~ = AC voltage (LP: LOGIC PROBE P = select pulse ; p = visible pulses)
|
Pin No.
|
Cable colour
|
Component/
Function |
In/out
|
Test conditions
|
Across
|
Test reading
|
See
|
|
1
|
YE/WH
|
Right brake light, power supply from TWICE to bulb.
|
Out
|
Brake pedal pressed.
|
1-B-
|
B+
|
Lighting and signalling systems
|
|
2
|
GY
|
Central locking motor for luggage compartment lock, relay.
|
Out
|
Not operated
|
2-B-
|
B+
|
Doors and locks
|
|
|
|
|
Activate function with diagnostics tool.
|
B+ -2
|
B+
|
|
|
|
3
|
BU/YE
|
Electrically adjustable passenger seat, ground relay.
|
Out
|
Ignition ON
|
3-B-
|
approx. 1V
|
Seats
|
|
|
Ignition OFF. Front doors closed.
Not operated. |
3-B-
|
B+
|
|
|||
|
4
|
BN
|
Starting relay
|
Out
|
Ignition key in position ST.
Transponder not OK. |
4-B-
|
B+
|
|
|
|
|
Ignition key in position ST.
Transponder OK. |
4-B-
|
<0.5V
|
|
||
|
5
|
BN/WH
|
Seat sensor, passenger seat.
|
In
|
Passenger seat occupied
|
5-21
|
<4.2V
|
Seat belt system
|
|
|
Passenger seat unoccupied.
|
5-21
|
5V
|
|
|||
|
6
|
YE/GY
|
Locking switch for central locking, centre console.
|
In
|
Ignition ON
|
6-B-
|
B+ for approx. 0.5 sec.
|
Doors and locks
|
|
7
|
YE/BN
|
Unlocking switch for central locking, centre console.
|
In
|
Ignition ON
|
7-B-
|
B+ for approx. 0.5 sec.
|
Doors and locks
|
|
8
|
BU/BN
|
Unlocking with key in passenger door.
|
In
|
Ignition ON
|
B+ -8
|
B+ for approx. 0.5 sec.
|
Doors and locks
|
|
9
|
BN
|
Heated rear seat, request.
|
In
|
Ignition ON:
Heated seat button held down. |
9-B-
|
B+
|
Seats
|
|
10
|
RD
|
Glass breakage sensor and angle sensor, power supply.
|
Out
|
Sensor not disconnected.
Anti-theft alarm armed. |
10-B-
|
B+
|
|
|
11
|
RD/WH
|
Switch for unlocking tailgate.
|
In
|
Ignition ON
|
11-B-
|
B+ for approx. 0.5 sec.
|
Doors and locks
|
|
12
|
BK/GN
|
Door switch, left rear door.
|
In
|
Ignition ON:
Door closed. |
12-B-
|
B+ for approx. 0.5 sec.
|
|
|
13
|
BK
|
Receiver remote control, ground.
|
In
|
Always
|
B+ -13
|
B+
|
|
|
13-B-
|
<0.5V
|
|
|||||
|
14
|
BN
|
Receiver remote control, signal.
|
In
|
Remote control not operated.
|
14-B-
|
B+
|
|
|
|
Press lock button.
|
14-B-
|
approx. 6V for approx. 0.2 sec.
|
|
|||
|
15
|
WH
|
I-Bus (-)
|
In/Out
|
Ignition ON:
Bus active |
15-B-
|
2-3V
|
|
|
16
|
YE/GY
|
Ignition +15, logic.
|
In
|
Ignition ON
|
16-B-
|
B+
|
TWICE
|
|
17
|
BN/RD
|
Ignition +B, logic
|
In
|
Ignition ON:
Key in ignition lock |
17-B-
|
B+
|
TWICE
|
|
18
|
RD/BK
|
Seat belt contact, driver's side.
|
In
|
Ignition ON:
Seat-belt on driver's side not connected to buckle |
18-B-
|
<0.5V
|
Seat belt system
|
|
|
|
Seat belt fastened
|
18-B-
|
B+
|
|
||
|
19
|
BU/RD
|
Angle sensor signal.
|
In
|
Ignition ON
|
19-B-
|
1.0V
|
|
|
20
|
VT/WH
|
Central locking motors rear doors, control voltage for theft security locking
|
Out
|
Not operated
|
B+ -20
|
B+
|
Doors and locks
|
|
|
|
|
Lock the car.
Activate function with diagnostic tool. |
20-B-
B+ -20 |
B+
<1V |
|
|
|
21
|
BN/OG
|
Seat sensor passenger seat, ground.
|
Out
|
Ignition ON
|
B+ -21
|
B+
|
Seat belt system
|
|
22
|
OG
|
Central locking motors doors, control voltage for locking
|
Out
|
Not operated
|
B+ -22
|
B+
|
Doors and locks
|
|
|
Car must be unlocked
Activate function with diagnostic tool. |
22-B-
B+ -22 |
B+
<1V |
|
|||
|
23
|
BU/WH
|
Parking light left rear, power supply from switch.
|
In
|
Light switch in position for parking light (pos 1).
|
23-B-
|
B+
|
Lighting and signalling systems
|
|
24
|
YE/GN
|
High level brake light, power supply from TWICE to bulb.
|
Out
|
Brake pedal pressed.
|
24-B-
|
B+
|
Lighting and signalling systems
|
|
25
|
BU/OG
|
Left brake light, power supply from TWICE to bulb.
|
Out
|
Brake pedal pressed.
|
25-B-
|
B+
|
Lighting and signalling systems
|
|
26
|
BU/YE
|
Central locking motor driver's door, control voltage for unlock
|
Out
|
Not operated
|
B+ -26
|
B+
|
Doors and locks
|
|
|
|
Car to be unlocked.
Activate function with diagnostic tool. |
26-B-
B+ -26 |
B+
<1V |
|
||
|
27
|
GY/WH
|
LED, theft protection.
|
Out
|
Activate function with diagnostic tool
|
B+ -27
|
approx. 1.95 V
|
|
|
28
|
RD/WH
|
Seat belt warning lamp, ground.
|
Out
|
Ignition ON
|
28-B-
|
<1V for 6 sec
|
Seat belt system
|
|
|
Seat belt fastened, more than 6 seconds since ignition ON.
|
28-B-
|
B+
|
|
|||
|
29
|
YE
|
Siren, communication
|
Out
|
Ignition ON
|
29-B-
|
B+
|
|
|
30
|
|
No connection
|
|
|
|
|
|
|
31
|
|
No connection
|
|
|
|
|
|
|
32
|
RD/VT
|
Locking with key in passenger door.
|
In
|
Ignition ON
|
B+ -32
|
B+ for approx. 0.5 sec.
|
Doors and locks
|
|
33
|
BU/BN
|
Unlock with key in driver's door.
|
In
|
Ignition ON
|
B+ -33
|
B+ for 0.5 sec
|
Doors and locks
|
|
34
|
BK
|
Angle sensor, ground
|
In
|
Always
|
B+ -34
34-B- |
B+
<0.5V |
|
|
35
|
BK
|
Luggage compartment switch
|
In
|
Ignition ON:
Tailgate closed. |
35-B-
|
B+ for approx. 0.5 sec.
|
|
|
Tailgate open.
|
35-B-
|
<0.1V
|
|||||
|
36
|
BK/GN
|
Door switch; right rear door.
|
In
|
Ignition ON:
Door closed. |
36-B-
|
B+ for approx. 0.5 sec.
|
|
|
Door open.
|
36-B-
|
<0.1V
|
|||||
|
37
|
BK
|
Signal ground
|
In
|
Always.
|
B+ -37
37-B- |
B+
<0.5V |
TWICE
|
|
38
|
GN
|
I-Bus (+)
|
In/Out
|
Ignition ON:
Bus active |
38-B-
|
2-3V
|
|
|
39
|
OG/BK
|
Immobilizer; code from antenna unit via ignition lock.
|
In
|
Ignition ON
|
39-B-
|
B+
|
|
|
Ignition OFF.
|
B+ -39
|
<0.1V
|
|
||||
|
40
|
|
No connection
|
|
|
|
|
|
|
41
|
RD/WH
|
Bonnet switch
|
In
|
Ignition ON:
Bonnet closed. |
41-B-
|
B+ for approx. 0.5 sec.
|
|
|
|
|
|
Bonnet open.
|
41-B-
|
<0.1V
|
|
|
|
42
|
VT
|
Central locking motor driver's side, control voltage for theft security locking.
Car to be locked. |
Out
|
Not operated
|
B+ -42
|
B+
|
Doors and locks
|
|
|
|
Activate function with diagnostic tool
|
42-B-
B+ -42 |
B+
<1V |
|
||
|
43
|
RD
|
TWICE, power supply +30 circuit.
|
In
|
Always +30
|
43-B-
B+ -43 |
B+
<0.5V |
TWICE
|
|
44
|
VT/WH
|
Central locking motor tailgate, control voltage for anti-theft protection locking.
Car to be locked. |
Out
|
Not operated
|
B+ -44
|
B+
|
Doors and locks
|
|
|
Activate function with diagnostic tool
|
44-B-
B+ -44 |
B+
<1V |
|
|||
|
45
|
GN/YE
|
Parking light left rear, power supply from TWICE to bulb.
|
Out
|
Light switch in position for parking light (pos 1).
|
45-B-
|
B+
|
Lighting and signalling systems
|
|
46
|
GN/WH
|
Parking light right rear, power supply from TWICE to bulb.
|
In
|
Light switch in position for parking light (pos 1).
|
46-B-
|
B+
|
Lighting and signalling systems
|
|
47
|
RD
|
Central locking, power supply from fuse.
|
In
|
Always +30.
|
47-B-
|
B+
|
Doors and locks
|
|
|
|
Activate any central locking function.
|
B+ -47
|
<1V
|
|
||
|
48
|
VT
|
Brake light, power supply from brake light contact.
|
In
|
Brake pedal pressed.
|
48-B-
|
B+
|
Lighting and signalling systems
|
|
49
|
BU/YE
|
Central locking motors rear doors, control voltage for unlocking.
|
Out
|
Not operated
|
B+ -49
|
B+
|
Doors and locks
|
|
|
|
|
Activate function with diagnostic tool
|
49-ground
B+ -49 |
B+
<1V |
|
|
|
50
|
GY/RD
|
Antenna unit for immobiliser, power supply.
|
Out
|
Ignition ON:
Without transponder |
50-B-
|
B+ for approx. 10 sec.
|
|
|
|
|
|
Ignition ON:
With transponder |
50-B-
|
B+ for approx. 0.1 sec.
|
|
|
|
51
|
YE
|
Tailgate opening, relay.
|
Out
|
Not operated
|
51-B-
|
B+
|
Doors and locks
|
|
|
|
|
|
Activate function with diagnostics tool.
|
B+ -51
|
< 0.5V
|
|
|
52
|
BU/RD
|
Heated rear seat, relay.
|
Out
|
Activate with diagnostic tool.
|
52-B-
|
approx. 1V
|
Seats
|
|
|
|
|
|
Not operated
|
52-B-
|
B+
|
|
|
53
|
|
No connection
|
|
|
|
|
|
|
54
|
|
No connection
|
|
|
|
|
|
|
55
|
BU/WH
|
Locking button, driver's door.
|
In
|
Ignition ON:
Locking button up. |
55-B- |
0 |
Doors and locks
|
|
|
|
Locking button down.
|
55-B-
|
B+ for approx. 0.5 sec.
|
|
||
|
56
|
RD/VT
|
Locking with key in driver's door.
|
In
|
Ignition ON
|
56-B-
|
8V for approx. 0.5 sec.
|
Doors and locks
|
|
|
|
|
Key in door lock in locked position.
|
56-B-
|
0V
|
|
|
|
57
|
WH/BK
|
Glass breakage sensor, ground
|
In
|
Always
|
B+ -57
57-B- |
B+
<0.5V |
|
|
58
|
GN/GY
|
Glass breakage sensor, signal
|
In
|
Ignition ON
|
58-B-
|
B+ for approx. 0.5 sec.
|
|
|
59
|
BU/WH
|
Boot lid switch for disarming anti-theft alarm.
|
In
|
Ignition ON:
Not operated |
59-B-
|
B+ for approx. 0.5 sec.
|
|
|
|
|
Turn the key to the unlocked position.
|
59-B-
|
<0.1V
|
|||
|
60
|
BK/GN
|
Door switch passenger door, front
|
In
|
Ignition ON:
Door closed. |
60-B-
|
B+ for approx. 0.5 sec.
|
|
|
|
|
|
Door open
|
60-B-
|
<0.1V
|
||
|
61
|
GY/GN
|
Door switch, driver's door.
|
In
|
Ignition ON:
Door closed. |
61-B-
|
B+ for approx. 0.5 sec.
|
|
|
|
|
Door open
|
61-B-
|
<0.1V
|
|||
|
62
|
BK
|
Central locking motor tailgate, ground
|
Out
|
Not operated.
|
B+ -62
|
B+
|
Doors and locks
|
|
63
|
|
No connection
|
|
|
|
|
|
|
64
|
|
No connection
|
|
|
|
|
|
|
65
|
GY/WH
|
Seat belt switch, passenger side
|
In
|
Ignition ON:
Seat belt on passenger side not connected to buckle |
65-B-
|
<0.5V
|
Seat belt system
|
|
|
Belt fastened
|
65-B-
|
B+
|
|
|||
|
66
|
VT
|
Central locking motor passenger side front, control voltage for theft security locking
|
Out
|
Not operated
|
B+ -66
|
B+
|
Doors and locks
|
|
Lock the car.
Activate function with diagnostic tool |
66-B-
B+ -66 |
B+
<1V |
|
||||
|
67
|
BU/YE
|
Central locking motor tailgate, control voltage
|
Out
|
Not operated
|
B+ -67
|
B+
|
Doors and locks
|
|
Activate function with diagnostic tool
|
67-B-
B+ -67 |
B+
<1V |
|
||||
|
68
|
BN/GN
|
Parking light right rear, power supply from TWICE to bulb.
|
Out
|
Light switch in position for parking light (pos 1).
|
68-B-
|
B+
|
Lighting and signalling systems
|
|
69
|
BU/YE
|
Central locking motor passenger door front, control voltage for unlock
|
Out
|
Not operated
|
B+ -69
|
B+
|
Doors and locks
|
|
|
|
Activate function with diagnostic tool
|
69-B-
B+ -69 |
B+
<1V |
|
||
|
70
|
BK
|
Power ground TWICE
|
In
|
Always.
|
B+ -70
|
B+
|
TWICE
|
|
|
|
Operate central locking function
|
70-B-
|
<0.3V
|
|
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