All values measured to ground unless otherwise noted
Conn./Plug/Pin	Pin Information	Test Value	Comments
N47-1
1.1	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
1.2	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
1.3	Pin not used
1.4	Stop lamp switch (normally closed) input	Ignition on, 12 VDC with brakes not applied, 0 VDC with brakes applied.
1.5	Pin not used
1.6	Parking brake switch ground signal input	Approx. 0 Ohms to ground with parking brake pedal depressed
1.7,8	Pins not used
1.9	"Diagnostic port" for DTC readout and diagnostic purpose	Ignition on 12 VDC	To be tested with HHT refer to D.M.
1.10	Circuit 15 switched power input, switched by relay K40/4k1	Ignition on 12 VDC
1.11	Stop lamp switch (normally open) input. Same signal as to brake lights	Ignition on, 12 VDC with brakes applied, 0 VDC with brakes not applied
1.12 1.13	Left rear axle VSS sensor, + input. Left rear axle VSS sensor, - input.	ECM disconnected 0.6-1.8 kOhms across pins 1.12 and 1.13 Sine wave. Frequency varies with wheel speed.	Note 1
1.14 1.15	Right rear axle VSS sensor, + input Right rear axle VSS sensor, - input	ECM disconnected 0.6-1.8 kOhms across pins 1.14 and 1.15 Sine wave. Frequency varies with wheel speed	Note 1
1.16-26	Pins not used
1.27	ASR OFF/ON recognition voltage coded signal input	Ignition on 5 VDC. ASR switch held in ON pos: 1 - 2 VDC Release switch: 3,3 - 6 VDC ASR switch held in OFF pos: < 1 VDC
1.28-30	Pin not used
2.1-16	Pins not used
2.17 2.18	Right front axle VSS sensor, + input Right front axle VSS sensor, - input	ECM disconnected 0.8-2.3 kOhms across pins 2.17 and 2.18 Sine wave. Frequency varies with wheel speed	Note 1
2.19 2.20	Right front brake pad wear recognition, lights indicator lamp when pads worn down	ECM disconected: Open circuit in normal condition. Short circuit with brake pads worn down.
2.21			see ETS Teves
2.22	Pins not used
2.23	Main ground to W29/2	Approx. 0 Ohms to ground or measure to circuit 30 12 VDC	Same as pin 2.47
2.24	Pin not used
2.25	Return pump relay activated monitoring signal input and pump voltage supply	12 VDC to pin 2.27 with relay activated
ETS Bosch
2.26 2.27	Return pump relay common output activation signal output	12 VDC to pin 2.26 with relay activated	Coil resistance approx. 40-80 Ohms
2.28	Switchover valve signal output, switched ground activates solenoid valve A7/3y5	12 VDC with valve energized 0 VDC with valve not energized ECM disconnected 5.4-12.6 Ohms to ground
2.29	Inlet valve signal output, switched ground activates solenoid valve A7/3y15	12 VDC with valve energized 0 VDC with valve not energized ECM disconnected 5.4-12.6 Ohms to ground
2.30	Right rear axle hold valve signal, switched ground activates solenoid valve A7/3y12	12 VDC with valve energized 0 VDC with valve not energized ECM disconnected 5.4-12.6 Ohms to ground
2.31	Right rear axle release valve signal, switched ground activates solenoid valve A7/3y13	12 VDC with valve energized 0 VDC with valve not energized ECM disconnected 2.8-6.6 Ohms to ground
2.32-34	pins not used
2.35	Left rear axle hold valve signal, switched ground activates solenoid valve A7/3y10	12 VDC with valve energized 0 VDC with valve not energized ECM disconnected 5.4-12.6 Ohms to ground
2.36	Left rear axle release valve signal, switched ground activates solenoid valve A7/3y11	12 VDC with valve energized 0 VDC with valve not energized ECM disconnected 2.8-6.6 Ohms to ground
2.37	Right front axle release valve signal, switched ground activates solenoid valve A7/3y9	12 VDC with valve energized 0 VDC with valve not energized ECM disconnected 2.8-6.6 Ohms to ground
2.38	Left front axle release valve signal, switched ground activates solenoid valve A7/3y7	12 VDC with valve energized 0 VDC with valve not energized ECM disconnected 2.8-6.6 Ohms to ground
2.39	Left front axle hold valve signal, switched ground activates solenoid valve A7/3y6	12 VDC with valve energized 0 VDC with valve not energized ECM disconnected 5.4-12.6 Ohms to ground
2.40	Right front axle hold valve signal, switched ground activates solenoid valve A7/3y8	12 VDC with valve energized 0 VDC with valve not energized ECM disconnected 5.4-12.6 Ohms to ground
2.46	Hydraulic unit solenoid valve power input	Ignition on 12 VDC
ETS Teves
2.21	Hydraulic unit solenoid valve power input	Ignition on 12 VDC	see Pin 2.37
2.26	Pin not used
2.29 2.27	Return pump relay common output activation signal output	12 VDC to pin 2.26 with relay activated	Coil resistance approx. 40-80 Ohms
2.28	Right rear axle hold valve signal, switched ground activates solenoid valve A7/3y12	12 VDC with valve energized 0 VDC with valve not energized ECM disconnected 5.4-12.6 Ohms to ground
2.30	Right rear axle release valve signal, switched ground activates solenoid valve A7/3y13	12 VDC with valve energized 0 VDC with valve not energized ECM disconnected 2.8-6.6 Ohms to ground
2.31	Switchover valve signal output, switched ground activates solenoid valve A7/3y5	12 VDC with valve energized 0 VDC with valve not energized ECM disconnected 5.4-12.6 Ohms to ground
2.32-34	pins not used
2.35	Right front axle hold valve signal, switched ground activates solenoid valve A7/3y8	12 VDC with valve energized 0 VDC with valve not energized ECM disconnected 5.4-12.6 Ohms to ground
2.36	Left front axle hold valve signal, switched ground activates solenoid valve A7/3y6	12 VDC with valve energized 0 VDC with valve not energized ECM disconnected 5.4-12.6 Ohms to ground
2.37	Hydraulic unit solenoid valve power input	Ignition on 12 VDC	see Pin 2.21
2.38	Left rear axle hold valve signal, switched ground activates solenoid valve A7/3y10	12 VDC with valve energized 0 VDC with valve not energized ECM disconnected 5.4-12.6 Ohms to ground
2.39	Left rear axle release valve signal, switched ground activates solenoid valve A7/3y11	12 VDC with valve energized 0 VDC with valve not energized ECM disconnected 2.8-6.6 Ohms to ground
2.40	Right front axle release valve signal, switched ground activates solenoid valve A7/3y9	12 VDC with valve energized 0 VDC with valve not energized ECM disconnected 2.8-6.6 Ohms to ground
2.46	Left front axle release valve signal, switched ground activates solenoid valve A7/3y7	12 VDC with valve energized 0 VDC with valve not energized ECM disconnected 2.8-6.6 Ohms to ground
2.41 2.42	Left front brake pad wear recognition, lights indicator lamp when pads worn down	ECM disconected: Open circuit in normal condition. Short circuit with brake pads worn down.
2.43 2.44	Left front axle VSS sensor, - input. Left front axle VSS sensor, + input.	ECM disconnected 0.8-2.3 kOhms across pins 2.43 and 2.44 Sine wave. Frequency varies with wheel speed.	Note 1
2.45	Pin not used
2.47	Main ground to W29/2	Approx. 0 Ohms to ground or measure to circuit 30 12 VDC	Same as pin 2.23
2.48	Circuit 30 main power input	12 VDC at all times
3.H	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 when data is on bus.	HHT is also used for CAN diagnosis
3.L	CAN-Bus (low side)
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.