Cannot pull codes from DM or LH-SFI modules 600SEL
 

Hi All,

Working on a 92 600SEL, but should be the similar with other W140. I’m trying to pull codes from the 38-pin socket (X11/4). I am able get codes from the following:
1. Socket # 8 for BM or GM (Base Module)
2. Socket # 7 for EA/CC/ISC or EGAS (Electronic Accelerator with Cruise Control/Idle Speed Control Module)
3. Socket # 18 for DI (Distributor Ignition Module) LEFT
4. Socket # 17 for DI (Distributor Ignition Module) RIGHT

I am NOT getting codes from the following:
1. Socket # 19 for DM or CARB (Diagnostic Module)
2. Socket # 5 for LH-SFI (LH Sequential Multiport Fuel Injection System Module) LEFT
3. Socket # 4 for LH-SFI (LH Sequential Multiport Fuel Injection System Module) RIGHT

I look high and low but cannot find anything that would cause this, wished I had a breakout box to see more but here are some conditions:
1. The car runs fine but “Check Engine is on”
2. Check the connections from the sockets where the modules go into the wire distribution to the Data Link Connector (X11/4) all Ohm out OK.
3. Fuses on the BM (Base Module) are ok, but the module is outputting code 10 and 13
4. Try 2 different BM (Base Module) still NO change a coincidences for 2 modules?
5. I am able get blink code from the Pushbutton with LED (X11/21s1) it is outputting 7 blinks
6. Try 4 different DM (Diagnostic Modules) still NO code this is too much of a coincidences if it was all these modules defective
7. Try 2 different sets of LH-SFI (LH Sequential Multiport Fuel Injection System Module) LEFT and RIGHT still NO code still a coincidences for 2 sets of modules?

Any help would be greatly appreciated, Thanks in advance

Thai GI