All values measured to ground unless otherwise noted
Conn./Plug/Pin Pin Information Test Value Comments
N47-5      
1 Stop lamp switch (normally closed) input.
 12 VDC with brakes not applied, 0 VDC with brakes applied.  
2 Brake pad wear recognition, lights
indicator lamp when pads worn down		 ECM disconected open:
Open circuit in normal condition.
Short circuit with brake pads worn down.		 Both sides via Z56/6
3
4		 LF VSS sensor, - input.
LF VSS sensor, + input.		 ECM disconnected
0.8-2.3 kOhms across pins 4 and 3
Sine wave. Frequency varies with wheel speed.		 Note 1
5 LF VSS output, generated by L6/1, processed in ECM and sent to other ECMs
 Ignition on, lift front of vehicle.
Turn left front wheel > 1 rev/sec by hand
> 3 VAC or with vehicle moving		 20 mph / 200 Hz
35 mph / 330 Hz
square wave
6
7		 LR VSS sensor + input.
LR VSS sensor, - input.		 ECM disconnected
0.6-1.8 kOhms across pins 6 and 7
Sine wave. Frequency varies with wheel speed.		 Note 1
8 DTC diagnostic output. Also input for SDS data and tests. Ignition on 12 VDC. No reliable test. Approx. 8 VAC when data transmission active.  
9 Lateral acceleration sensor voltage supply low side and sensor ground same as pin 24  
10 Lateral acceleration sensor signal input Ignition on measure to pin 9
move vehicle in laterally direction > 10mVAC		  
11 Brake pressure sensor 1 voltage supply low side and sensor ground Ignition on
measure to pin 26 5 VDC		  
12 Brake pressure sensor 1 signal input
equivalent to force applied to brake pedal		 Ignition on
depress brake pedal > 2 VDC		  
13 Brake release switch
normally open signal		 Ignition on
brake applied < 1 VDC, not applied 12 VDC		  
14 BAS solenoid valve activation signal output
activated from sensor A7/7b1 output signal		 Ignition off ECM disconnected
measure to pin 2.5 < 5 Ohms		  
15 CAN-Bus "low side". High speed data
transfer bus input and output. Shares data with other ECMs		    
16 CAN-Bus "high side". High speed data
transfer bus input and output. Shares data with other ECMs		 No reliable test. Check continuity to other ECMs. Approx. 5 VAC across pins 16 and 15 when data is on bus. SDS is also used for
CAN diagnosis
17 Stop lamp switch (normally open) input.
Same signal as to brake lights.		 12 VDC with brakes applied, 0 VDC with brakes not applied. via K55
18 Circuit 87 power input, applied from K40 relay module Ignition on 12 VDC Feed from circuit 30 via K40/4
19,20 Pins not used    
21 Membrane travel sensor signal input
detects emergency brake situation and initialises BAS function		 Ignition on
brake not applied < 1 VDC, applied 5 VDC		  
22 Membrane travel sensor
voltage supply output low side (ground)		 Ignition on 4.75 - 5.25 VDC
Ignition on 12 VDC, to circuit 30 pin 45 & 47 		 
23 BAS solenoid valve power supply output Ignition on 4 - 5.5 VDC  
24
 Lateral acceleration sensor voltage supply
output		 Ignition on
measure to pin 9 5 VDC		  
25 Rotating speed sensor voltage supply output
low side		 Ignition on
measure to pin 25 12 VDC		  
26 Brake pressure sensor 1 voltage supply output same as pin 11  
27 Brake pressure sensor 2 voltage supply low side and sensor ground Ignition on
measure to pin 40 5 VDC		  
28 Stop lamp suppression signal output
activated during system brake initialization 		No reliable test  
29 Steering angle sensor signal input Disconnect ECM,
ignition on > 3 VAC		  
30 ESP OFF/ON recognition. Voltage coded signal from S76/6. Low sets ESP OFF. High sets ESP ON. Ignition on 5 VDC.
ESP switch held in OFF position: Approx. 1-3 VDC
ESP switch held in ON position: 0 VDC		  
31 Parking brake signal input controls
indicator lamp A1e7		 Parking brake pedal depressed
Ignition on 0 VDC		 Feed from S12
via CAN to IC A1e7
32
33		 RF VSS sensor, - input.
RF VSS sensor, + input.		 ECM disconnected
0.8-2.3 kOhms across pins 33 and 32
Sine wave. Frequency varies with wheel speed.		 Note 1
34 RF VSS output, generated by L6/2, processed in ECM and sent to other ECMs
 Ignition on, lift front of vehicle.
Turn right front wheel > 1 rev/sec by hand
> 3 VAC or with vehicle moving		 20 mph / 200 Hz
35 mph / 330 Hz
square wave
35
36		 RR VSS sensor - input.
RR VSS sensor, + input.		 ECM disconnected
0.6-1.8 kOhms across pins 36 and 35
Sine wave. Frequency varies with wheel speed.		 Note 1
37
 Membrane travel sensor
voltage supply output low side (ground)		 same as pin 22  
38 Rotating speed sensor voltage supply output
high side		 Ignition on
measure to pin 25 12 VDC		  
39 Rotating speed sensor signal input
actual driving situation value		 No reliable test To be tested with
SDS refer to D.M.
40 Brake pressure sensor 2 voltage supply output same as pin 27  
41 Brake pressure sensor 2 signal input
equivalent to force applied to brake pedal		 Ignition on
depress brake pedal > 2 VDC		  
42 Brake release switch voltage supply output Ignition on 12 VDC  
43
 Brake release switch
normally closed signal		 Ignition on
brake not applied < 1 VDC, applied 12 VDC		 See pin 13
44
 Main ground to W16/3 Approx 0 Ohms to ground  
45 Circuit 30 main power input 12 VDC at all times Feed from F23/1
46
 Main ground to W16/3 Approx 0 Ohms to ground  
47 Circuit 30 main power input 12 VDC at all times Feed from F23/1
48 Pin not used    
Note 1 To test, spin wheel at 1 rev/sec, measure at least 120 mVAC between both wires of sensor. If voltage is OK, measure the sensor's resistance while pulling, twisting and bending the sensor wires, looking for intermittent opens. Finally, check the sensor tip and rotor teeth for dirt or breakage. An oscilloscope can also be used to check the waveform - chipped or dirty teeth show up as missing or malformed waves.