Here are some pics of my E320's intake manifold vacuum connectors showing the circled nipple from your photo as the one going to the DM pressure sensor (B5/2) shown in pic 2.

The other nipple closer to the cylinder head has a Y connector going to both the fuel pressure regulator (40), and air injector (Y32) & EGR valve (Y27).

It's exactly how the diagram I posted above shows.








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I apologize. I circled the wrong area. The area I circled is where my lower intake has a nipple. So I am almost positive my 1993 has a 92' lower intake which has that extra nipple. 93'. Now I am almost certain that that nipple is probably capped with a rubbed cap.

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No problem. On my E320, that nipple connects to the 3 prong vacuum supply connector behind the brake booster (135). I should know since I just replaced the rubber boot connecting a white vacuum hose to that nipple a few weeks ago. See vacuum line at bottom of pic below.



The right-most of those 3 prongs connects to the transmission upshift retard switchover valve that has a green hose going to the transmission retard switch. It retards 2nd to 3rd gear upshifts at coolant temps below 50 C.

The other two lines go to the vacuum reservoir for door/boot/gas locks and HVAC flaps.




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Sorry for lengthy explanation above. I just looked at the circled area again and my intake manifold does not have that nipple there as well.


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I took the ETA out and out in a new ETA gasket.
I drove the car for 30-40 miles and the CEL triggered.
The DM codes that came up were 4,5, and 6.
I checked pin 8 and got a code 8.
I checked pin 14 and got a code 2.
These are the codes that returned within 30-40 miles..
I don't remember having DM codes 4 and five before. I had DM 6 and 17 in the past.
maybe 4 and five came after I possibly bumped a vacuum line. I will check hoses again.

Do any of the codes above indicate a clogged egr tube?

I]other issues I am having is that my cruise control is not working either.

Any chance that these code are related to a clogged egr tube?
In addition, my cruise control doesn't work any more.
Car doesn't run too badly, but the idle drops a little too much when the AC is turned on.

just a thought, too..is the ETA wiring issue which was similar to the engine wiring harness. My E320 required a new ETA for the ASR type system in 2005 due to the eco-junk wiring. Somebody said if its not one thing, its two. Hope you dont have bad ETA wiring. good information on this around the vacuum system! Thanks for details!

PS, the note about cruise control suggests the ETA wiring is faulty..But these other guys are way ahead of me here! I had a 94 coupe with the M104 and the cruise would drop if I hit a bump. clearly an insulation degradation issue.

Solved.
Thanks too all who chimed in on this thread.
Mercron, great pics and diagram.
I appreciate Arthur Daltons help as well.
Puzzler, it was the ETA.


I suspected it too, but had wishful thinking that it wasn't the ETA.
Put in a used but in working ETA and everything is working really well now.
My other codes related to vacuum lines were resolved-I had accidentally knocked of a line that didn't have much slack on it. I gave it more slack and hooked it back up.

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If you look close, notice that all of the wires, except the black ones, have deteriorated insulation ! We all know about the eco junk wiring etc., but wow !

Codes 4 for the air injection and 5 for the EGR faults could be related if you knocked off the vacuum hose going to the two switchover valves they're connected to.

Glad you solved it with the ETA wiring.




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Stevester 500E, thanks for sharing! Good to know. Im getting there and glad to know you solved this. I hit the jackpot with my $600. E320 finding it had a 2005 ETA installed by the dealer. I tore it all apart trying to diagnose a crazy fuel pump failure which was intermittent. I suspected the E-modules, the ETA and everything but fuel pumps which were both previously working fine, then BOTH failed within a week! Your car must be an ASR model. My transmission is trying to fail and here I have a bullet proof engine and $1000 worth of new parts and still looking at another $2000 repair to do the transmission. But hey, my self-leveling suspension works great.. Hope you found the ETA for a reasonable price..

Maybe you can find a deal on a good used transmission. Sometimes you can find a car being parted out with a fairly recent transmission rebuild.