All values measured to ground unless otherwise noted
Conn./Plug/Pin	Pin Information	Test Value	Comments
N3/4
2.1	Adjustable camshaft timing signal output, determines camshaft timing correction	Engine at approx. 2000 rpm, ECT >70 °C 1-1.5 A current draw across Y49 Engine at idle Insert bridge to gnd (max. 10 sec.) engine runs rough or stops
2.2	Injector 4 timing signal output controls fuel injection quantity	Use scope, probe tip to pin 1.39, ground to pin 2.2 ECT 20 °C start engine approx. t=8 msec. ECT 80 °C engine at idle approx. t=3-5 msec. accelerate briefly approx. t=17 msec.	Waveform needle pulse approx. 40 Vpp coil 14-17 Ohms
2.3	Pin not used
2.4 2.26	EA/CC/ISC actuator motor control signal output low side high side	Ignition on, 0.8-2.3 VDC Engine at idle, ECT > 70 °C voltage varies from 1.0-2.5 VDC Ignition off, approx. 10 Ohms	P/O M16/2 see also pins 2.6 and 2.18
2.5	IAT sensor signal input temperature relating voltage	Engine at idle, ECT > 70 °C 0.8-1.1 VDC voltage raises with increasing rpm
2.6 2.18	EA/CC/ISC potentiometer 1 and 2 power output, low side high side	Ignition on approx. 5 VDC to pin 2.18 (+)
2.7	EA/CC/ISC potentiometer 2 signal input determined by accelerator pedal position	Ignition on, measure to pin 2.6 (-) accelerator pedal position CTP 0.3-0.9 VDC, WOT > CTP value	P/O M16/2 see also pins 2.6 and 2.18
2.8	CKP sensor signal input high side CKP status affects injection system timing	Engine at idle > 0.2 VAC to pin 2.19 voltage raises with increasing rpm. Coil resistance approx. 0.9 - 1.6 KOhm
2.9	Ignition coil 2 signal output	Ignition on 12 VDC Starter cranks > 6 VDC
2.10-11	Pin not used
2.12	Injector 3 timing signal output controls fuel injection quantity	Use scope, probe tip to pin 1.39, ground to pin 2.12 same as pin 2.2
2.15	Air pump activation switched ground signal output, activates relay K1	Substitute ECT sensor by 2.5 Kohm resitor engine at idle 12 VDC and air pump is running duration approx. 2 min.
2.16-17	Pins not used
2.19	CKP sensor signal input low side	See pin 2.8
2.20	Pin not used
2.21	Ignition coil 1 signal output	Ignition on 12 VDC Starter cranks > 6 VDC
2.22	Main ground to W16/6	Approx. 0 Ohms to ground or measure to circuit 30 12 VDC
2.23	Injector 1 timing signal output controls fuel injection quantity	Use scope, probe tip to pin 1.39, ground to pin 2.23 same as pin 2.2
2.24	Injector 2 timing signal output controls fuel injection quantity	Use scope, probe tip to pin 1.39, ground to pin 2.24 same as pin 2.2
2.25	EGR valve switchover signal output to initialize NOX reduction circuit	Engine at idle, measure to circuit 87 pin 1.39 accelerate briefly voltage changes from 0 to 12 VDC
2.27	Ground signal to IAT sensor	Disconnect plug, measure to pin 2.22 < 20 Ohms
2.28	Temperature sensors ground signal	See pins 2.36 and 2.37	B17, B11/3 (IAT/ECT)
2.29 2.30	CKP sensor signal input low side (shield) CKP sensor signal input high side CKP status affects injection system timing	Start engine > 0.4 VAC, at idle > 1 VAC voltage raises with increasing rpm or use scope: sine wave 30 Vpp, t=0.7 msec. at idle	Coil resistance 0.7 - 1.4 Kohm
2.31-33	Pins not used
2.34	Idle Speed Switch	Ignition on 12 VDC Measure to pin 2.22 Idle Speed: < 3V Accelerator pedal activated: > 10V
2.35	Pin not used
2.36	ECT sensor signal input	Ignition on, measure to pin 2.28 ECT at: 20 °C approx. 3.5 VDC 60 °C approx. 1.9 VDC 80°C approx. 1.2 VDC
2.37	IAT sensor signal input	Ignition on, measure to pin 2.28 ECT at: 20 °C approx. 2.6 VDC 60 °C approx. 0.9 VDC 80°C approx. 0.5 VDC
2.38	Pin not used
2.39	EA/CC/ISC potentiometer 1 signal input, determined by accelerator pedal position	Ignition on, measure to pin 2.6 (-) accelerator pedal position CTP 4.0-4.6 VDC, WOT < CTP value	P/O M16/2 see also pins 2.6 and 2.18
2.40 2.41	Knock sensor 1 signal input low side Knock sensor 1 signal input high side affects ignition system timing	Ignition on, use oscilloscope tap on engine block see signal vary (looks like noise) Piezo element generates increasing voltage with increasing knock signal
2.42-44	Pin not used
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). high speed data transfer bus input and output, shares data with other ECMs