The 928s4 uses a LH 2.3 which is very similar as you can see.

 

Yellow: EZK, Red: LH2.3 ecu 

The next picture shows the 92pin diag connector as used in the 928 MY 1989 and onwards. It is the same as in the 964 and 968 models.

This picture shows the 12pin diag connector with the dummy cover, and the CO adjust device. it is for the idle-mixture pot for cars without cats.

 

 

Diagnostics port on a 928s4 MY 1988  
       
  1 over fuse 7 to bus 15: switched 12v  
  2 gnd via MP IX + shield ground  
  3 pin 13 EZK: Speedpulse to LH pin 1  
  4 pin 14 EZK: knock registration input from diagnose plug to EZK  
  5 over fuse 24 to bus 30: unswitched 12v  
  6 nc  
  7 nc  
  8 nc  
  9 pin 22 EZK, shielded: Hall sender pulse  
  10 pin 12 LH+EZK, shielded: K-line diagnostics  
  11 pin 22 LH: Display (check) Engine check  
  12 pin 7 EZK, shielded: L-line diagnostics  
       

 

 


 

 

This is a picture of the early Ezk .10 ecu of which some say it does not exist:

Item is a EZK ignition engine control unit from a 87 928 S4, original part # 928 618 124 11. This unit fits 87 928 S4 models.
possibly a non-dia, I'm not 100% sure, depends on the installed eprom.

 

Some info from http://www.scotsglen.com/saab/ecu/index.htm

and http://saabnet.com/tsn/faq/lhoverview.html

LH 2.4 (I think its a late 80's or early 90's model)

some data on a LH 2.4.2 

Pin #  Lead Color Component/Function I/O Voltage
1 Blue Engine speed signal  Input 6.5 - cranking, >8 -  idle
2 Gray Throttle Position Switch(Idle) Input 0 - Idle , ~11 - Above idle
3 Green/Red Throttle Position Switch(WOT) Input 0 - WOT, ~11 - Before WOT
4 Red Power supply +30 Input 12
5 Black Signal Ground   0.0 - Separate from power ground
6 Blue/White Mass air flow    Ground 0.0 - Separate from power ground
7 Orange Mass air flow Input 2.0 - Idling, 5.0 - Full Load
8 Red/White Mass air flow, burn-off    Output 4.0 - At burn-off, 0 -otherwise
9 Gray/White Power supply from main     Input 12
10        
11 Green/Red A/C Time-delay Relay    
12 Blue/White Diagnostics lead I/O  
13 Yellow Temp Sensor Input 4(-20C) -0.5(80C)
14 Red/White A/C, ACC load Signal Input 12-Auto, 0-ECON
15 Green/Yellow Jumper for cold start   0-no cold start, 12 cold start
16 Green/Red Diagnostics Lead I/O  
17 Black/White Chassis Ground Ground  
18 Green/White Injectors control signal Output 7.1Hz, 2.4-4.5ms
19 Yellow/White EGR Valve Output 12 - inactivated, <12 active
20 Violet Fuel Pump relay signal   1-activ, 12-Ign on
21 Yellow/White Main relay operating circuit Output 1 - Ignition on, 12 - Ignition off
22 Violet/White Check Engine Light Output 12-off, 1-on
23 Yellow/White EGR Temp Sensor Input 4.5 -EGR closed, <4.5 -Open
24 Green Oxygen Sensor Input 0.6 - 1.0 - Rich, 0.0 - 0.4 - Lean
25 Blue/Red Load Signal Tq (EZK/DI) Output Freq incr with throttle opening
26 White Shift-Up light Output 12 - Not activated,0 - Activated
27 Yellow/Red EVAP Canister purge valve Output 12 - Open, 1 - Closed
28 White PRE-IGNition, DI/APC Input 0-Preign, 6.5-stable, 12-knock
29 Gray/White Codification Input 12 - Automatic transmission
30 Orange Raising engine idle speed Input 12-R,D,1,2,3, 0 - P,N, and manual
31 Green/Red Consumption signal to EDU Output Freq incr with throttle opening
32 Brown Cold start valve Output Battery voltage - Not activated
33 Blue/White IAC valve Output 5-11 - Idling, no load
34 Green Speed Sensor Input 6 -Rotating, 0 or 12 - Stationary
35 Green/White Power Supply +15 Input 12-Ign on