All values measured to ground unless otherwise noted
Conn./Plug/Pin Pin Information Test Value Comments
N3/4      
1.9 Transmission overload protection signal input, to reduce power in case of AT overload Engine at idle approx. 5 VDC  
1.30 O2S heater activation signal (before TWC) Ignition on approx. 0.6-3.4 A current draw to circuit 87 pin 39
Engine at idle for at least 2 min. ECT > 80 °C
12 VDC		  
1.34
1.35		 02S signal input, low side
02S signal input, high side		 Engine at idle for at least 2 min. ECT > 80 °C,
measure across pin 34 and 35 voltage varies
> 0.3 VDC in a range from -0.2 to 1.0 VDC		  
1.42 Upshift delay signal output activated to shorten warm-up time of TWC Ignition on measure to circuit 87
approx. 0.4-0.6 A current draw		  
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 3 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 Injector 4 timing signal output
controls fuel injection quantity		 Use scope, probe tip to pin 1.39,
ground to pin 2.3 same as pin 2.2		  
2.4 Pin not used    
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		  
2.6,7 Pins not used    
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 Ignition coil 3 signal output Ignition on 12 VDC
Starter cranks > 6 VDC		  
2.11 Pin not used    
2.12 Injector 5 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		  
2.13 Injector 2 timing signal output
controls fuel injection quantity		 Use scope, probe tip to pin 1.39,
ground to pin 2.13 same as pin 2.2		  
2.14 Resonance intake manifold switchover signal output, activates valve depending on rpm Engine ai idle, measure to circuit 87 pin 1.39 accelerate to > 3900 rpm
voltage changes from 0 to 12 VDC		  
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.		  
2.16-18 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 6 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		  
2.26 Pin not used    
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, B11/4 (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
2.31-35 Pins 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		  
2.38,39 Pins not used    
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
2.43		 Knock sensor 2 signal input low side
Knock sensor 2 signal input high side		    
2.44 Pin not used