[TimeCapsule]

My car is an early 600 coupe. Currently off-road, as the attempts to recommission it have stalled.
California-spec, which means faults in the emissions equipment trigger the nasty red CEL.

I am at wits' end - fixed almost everything else, but cannot get rid of the 023 code, logged in both the LH and DM modules (DM 021 and DM 053).

The regeneration switchover valves y58/2 and y58/3 in the MB language are what we also call purge valves or MOT valves. They are simple solenoid valves, which I've taken to the bench, cleaned, tested.

Startek gives the following description of the fault:

Left or right purge control valve (Y58/2 or Y58/3), open/short circuit

Well, the valve has a simple 2-pin connector, with pin #2 being a red/blue power wire (from the Basic module), which I have confirmed is live at idle.

Pin #1 is red/brown signal wire from the LH modules, and I believe my problem is here.
If I understand the wiring diagram correctly, this is a DIRECT connection between the plug for the purge valve and the N3/3

But, with my ohm-meter, I cannot confirm continuity between pin 38 of the base of the N3/3 module and pin 1 of the y58/3 connector.

Same issue with the N3/2 and y58/2. Power is confirmed, but the wire that should be providing the cycling signal from the LH module is broken.

Is there anything that I am missing?

Thank you for your help.

 

[kubasz]

There are two sockets for each LH module and both sockets have pin no 38. Make sure to measure the connection on the socket with no CAN-Bus.

 

[TimeCapsule]

There are two sockets for each LH module and both sockets have pin no 38. Make sure to measure the connection on the socket with no CAN-Bus.

Thanks for the suggestion and many thanks for trying to help (I've seen your U-tube channel, you've got awesome stuff there!).

I tried both rows, for both the green and the blue bases. I cannot get the ohm-meter to show continuity to any of the pins.

For sanity check though, I did confirm that I have continuity between the pin #2 of the valve connector and the respective pin in the base module (all possibilities crossed my mind - from my not being able to read diagrams and to use ohm-meter, to the last straw - the car being super early coupe to have a slightly different pin-out, not documented in StarTek)

 

[TimeCapsule]

Before I tear into the coffin box again (I wish I knew that this would be a problem when I had the box split in half to solder-in new wiring for the MAFs), I would like to ask the forum if there is another relatively easy/quick way to run a test wire from pin #38 of the LH module to the purge valve connector - pin #1?

This is just to confirm that I can get the purge system running and the CEL will not be lighting up anymore.

 

[TimeCapsule]

My efforts to trace the wiring from the regeneration valve to the LH modules were not successful.
I ended up splitting the coffin box and running two new wires from pin #38 of both the LH1 and LH2 (green and blue) connectors.

As you can see, I had already done my MAF wiring repair and wish I didn't have to go back. There is a small possibility that no continuity on pin #38 may have something to do with my prior work, but I did not find anything obvious.

Now, with everything buttoned up, the DMM shows continuity (the reading shows slightly higher resistance but I am using a cheap DMM and my other hand is holding the camera):

and

 

[TimeCapsule]

Sadly, after a few days in the garage and on the computer reading wring diagrams, I must admit defeat.
Still no action from the regeneration valves. The codes reappear and the CEL is lit again.

I have lost sleep on this :-((

The odds are almost astronomical that the same mistake would occur on both banks before and after the new wires...and I find it very odd that everything else works as it should, MAFs included.

There must be something that I am doing wrong, anyone?

 

[kubasz]

You can go to LH module on SD and try to activate the purge valve there in Activations menu.
Have you tried to measure this valves coil? Put your dmm on the valve pins and see if its good. Not sure what reading you should get but i guess something close to 10ohm.
Do you get 12v on the valves pin no2?

 

[TimeCapsule]

You can go to LH module on SD and try to activate the purge valve there in Activations menu.

I just tried it. My first time. So far, I have only used 2 and 3 from the list.
Going to 4, it asks to engage parking brake and turn off ignition, then turn back on, wait and start the engine.
That could not happen.

Have you tried to measure this valves coil? Put your dmm on the valve pins and see if its good. Not sure what reading you should get but i guess something close to 10ohm.

Yes, I tested both on the bench. Resistance is close to 30 Ohm and applying power with a 9V battery opens the valve up.

Do you get 12v on the valves pin no2?

Yes, I have 12V on pin #2. Confirmed it all the way to the BM


Many thanks for your input.

 

[TimeCapsule]

Since I posted the negative result from my first attempt at running control element actuation, I have been reading posts on the subject "HHTwin".

This long-running thread on the R129 side caught my attention since more than one member commented on the same issue I encountered.

HHTWIN SDS Advice and issues

This is unfortunately common with c3's on older ones the relays go bad I have also seen bad cables. The c3 got pretty cheap on aliexpress $150 or without cables. You could get a new one and hope for the best. If you want to to be on the save side get 's c4. Sent from my SAMSUNG-SM-G870A using...

www.benzworld.org

Post #133 - he was initially considering a faulty multiplexer, faulty cable, or need for an internal battery (I am using a C3 with no provision for internal power), but later established that the "faulty" MUX can actuate modules on a different car.

Can someone with a LH (1992, 1993 or 1994) car confirm that actuation of the purge valves is possible?

Thanks much.

 

[TimeCapsule]

I am going crazy on this issue, could really use some help.
Managed to borrow another Star SDS and with it was able to access the actuation functions. Apparently I either have a bad MUX or something with the cables precluded me before from doing so with my own unit, but this is a subject for another post.
Unfortunately, the attempts to actuate both solenoids failed. I got another error messages confirming that Y58/2 and Y58/3 circuits are messed up.
LH1 and LH2 - same outcome. How can it be?

 

[TimeCapsule]

I really need help from you guys with training in electrical engineering. I know I am doing something wrong. The solenoids are receiving power (apologies again, cheap DMM and poor ground explain why the voltage is not 14 but slightly below with a running engine)

but they do not click or open/close in any way.

The signal wire is new and uninterrupted from the the connector to the coffin box.

I know it is a moot point, but I wanted to test the signal form per StarTek

This is how I run a tiny wire out of the coffin box (pin #1.36) to plug my cheap scope:

The other end I connected to the purge valve connector pin #1.

Nothing!

Decided to measure the current draw as in StarTek between pins #1.23 and #2.38 with the module out and ignition on - step 25.1 - however, these tries on both LH sides promptly blew the 10A fuses of the base module.

Am I misreading the instructions or doing the test wrong?

 

[TimeCapsule]

The picture provided in post 10 showing the error message that I got after attempting to actuate the solenoids has a symbol that actually clarifies the problem ( |- -| + ). I was no aware of that.

Looking up the code in StarTek gave the following explanation:

Left or right purge control valve (Y58/2 or Y58/3), open/short circuit

However, digging a bit deeper in HHTwin for an unrelated problem, I found that the problem is short to positive

 

[Redrodent]

This may not help, but could help your though process. I have gotten killed like this on low voltage building control systems. You get off on wild tangents, and it ALWAYS ends up being something basic. Voltage will show on a meter from a single wire strand or a terrible connection (ghost) and not do squat under load. Do the valves use a common ground? Build a simple physical load with a light to plug into the valve connector to visually see what’s happening? Apply voltage at the module harness (with a fuse of course) to manually activate the valves? As long as you have someone to bounce ideas off and keep your head clear, you can fix it,

 

[TimeCapsule]

Apply voltage at the module harness (with a fuse of course) to manually activate the valves?

Brilliant idea! Thanks much! I just did it. LH module provides the ground, I used a short jumper wire from a nearby known good ground point. I ran separate 20 ft long wire directly from the battery + to the purge valve. Clicks right away.

Short to POS or output stage fault?

 

[TimeCapsule]

For closure and posterity. After weeks of chasing this problem, I am relieved (and ashamed to admit it) that the solution was in plain sight. I glanced over it multiple times, but did not see it. Here:

I still don't know what caused the wiring fault to begin with (not the only Ohm-law conundrum I am facing as I still have another wiring battle with the S17/3 and S17/4 circuits that is presently ongoing), but I do know that resetting the LH modules restored the functionality.

The moral of the story - and confirming what @Redrodent said earlier about the solution always being something basic -- RTFM!!

 

[TimeCapsule]

Short to POS or output stage fault?

Can a moderator please help me edit post #14. When I submitted it, I did not realize that POS may have multiple meanings, especially when the letters are capitalized. Now I see how inappropriate that can be
For some reason I am not allowed to correct the mistake. I meant "positive" )