EDS Codes on 1992 300D 2,5 Turbo - PeachParts Mercedes-Benz Forum

BigBen · #1 10-03-2006, 10:37 PM

I just read the codes earlier on today for the very first time since owning this car. It has, btw, some 530 000km (330k miles).

I got the following codes, but I'm missing some details for a few:

In the order they appeared:

15
8 B11/4 Coolant sensor
9 B2/1a Intake air temp.
2 L7 Fuel rack sensor
3 B2/1 Air flow sensor
11
5

Could anyone help with 15, 11 and 5? I read 11 will always be there... right?

I do experience erratic turbo response and power loss, but I haven't hooked a boost gage yet, so I'll do my work and come back.

I still need to look at the basic timing as well and see if I have a stretched beyond limit timing chain (> 4 deg from what I've read).

I seem to be getting time from 0-62mph in the order of 16-17s when speed is read from speedometer. Fuel tank almost empty and rear seat removed.

I will install my veggie kit on this car after I have gotten it to work perfectly on diesel.

Thanks

BigBen · #2 03-11-2007, 05:01 PM

Well, I just hooked on the turbo boost guage yesterday.

I previously felt the car erratic in power, now I've seen it on the guage!

So, I do get very decent boost at times, 13-14psi guage reading.

The problem is that, while in 2nd gear an holding the pedal steadily down(but not engaging the kickdown switch), boost will vary like this:

1800 RPM 10psi
2300-2800 RPM 13psi
3000 RPM 5 psi
3200-3500 RPM 13psi
Boost stars to drop with higher revs (fine with me, I like boost at low RPM).

It seems I have a "flat spot" in the boost response and performance.

I have another related symptom: At some point, I will lose boost totally, reaching only 2 or 3 psi, no matter how I drive the car.

Switching the ingnition key to OFF and back ON within a couple seconds will resume operation with erratic boost described here previously.

When the boost is there, the car really goes well with lots of power. I gotta get it to work properly.

So I came back and read plenty of interesting posts about ALDA adjustments, timing, EGR and EDS.

I am starting to think I may have a bad B2/1 Air Flow Sensor.

I've tried reading resistance from the B2/1 Air flow sensor, but I don't know the exact pin out... How could one test this MAF sensor?

My EDS codes read exactly as my original message, oh goch, 1 yr ago already!!!

BigBen · #3 03-12-2007, 03:33 PM

Here is an under hood picture of my car with naming of components, hoping this can be useful for future reference.

I still don't know if this is all actually right?

I am still missing the whereabouts for the Y31/5 Wastegate transducer...

It seems I am having a nice discussion with myself! I think I'm getting there though.

Bye

pmari · #4 03-13-2007, 08:04 PM

How did you do, ya find it? I see you were here2.5 Turbo Boost problem. already.

BigBen · #5 03-13-2007, 11:02 PM

pmari,

Not yet resolved the issue.

After reading multiple posts here, I will try the following test this week-end: Plug in a permanent vacuum to the wastegate actuator and supply manifold boost pressure directly (and only) to the ALDA, which should give me boost all the time, unless I have a problem with the Wastegate vacuum actuator (bad leak).

Depending on results, I will focus on testing individual components for proper operation.

I have removed the the intake manifold in November, cleaned it up (it was full of gunk, greasy stuff), cleared the boost line to ALDA and EDS (they were not that bad), changed GP while in there and replaced the delivery valve seals on the IP (I also changed the fuel lines around the IP going to the fuel filter head).

So I'll do my homeworks and come back with more news/details/results.

BTW, I am not able to clear the codes in the EDS by holding a wire between test port X11/4 and ground for 8 seconds, although this gives me the codes correctly when holding the wire in same place for 2-3 seconds...

Thanks for your reply, makes me feel less lonely!

Bye,

BigBen · #6 03-24-2007, 10:25 PM

Well, it seems I have a leaking Y31/1 and Y31/5 plus an equally leaking Intake Flap actuator.

Plus my Y31/5 wastegate vacuum transducer had been poorly repaired with no connectors on the terminals and quite some corrosion (see picture, after minimal cleaning)

I think this is plenty enough to cause most errors my EDS computer had been getting.

So I'll get the parts next week and come back again.

Slowly, but surely, I'm getting towards the solution.

Bye

#7 03-24-2007, 10:39 PM

transducer? codes? computer?????

I'm sure glad mine doesn't have any of that.

2.5Turbo · #8 03-25-2007, 02:26 AM

Wow, that's pretty nasty/dirty.

Swap your one good one onto the turbo wastegate and put the two bad ones on the EGR and intake flap, then you'll at least have boost until the computer figures out that they're bad.

The computer monitors the airflow sensor to determine if the EGR and intake flam are operating properly. That's why you get the airflow sensor code along with the air temp code (they're on the same assembly actually). I believe the rack sensor code is activated when the computer thinks the rack should be opened farther than it is for the amount that you're pressing the pedal. Of course, it isn't opening that far because there is no boost, hence the code. IIRC, 15 is is a general code for the transducers. It is finding out that they're bad. Not sure why you're getting a coolant sensor code...I never did while diagnosing this problem. See if it comes back after all codes are cleared and the transducers are replaced. You'll always get a code 7 IIRC when the key is in position 2 with the engine not running. 5 is there because your EGR transducer isn't working. Can't remember what 11 is, as WIS isn't installed on this computer, and the one that it is installed on is 2500 miles away at the moment

Interesting to note that on my car, I don't always get a code 11(and I don't think I ever have), and mine is a 1990. I read that all EDS units up to 1991 always showed a code 11. When mine is cleared out, I get the all-is-well code 1.

BigBen · #9 03-26-2007, 10:45 AM

Quote:

Originally Posted by 2.5Turbo

Swap your one good one onto the turbo wastegate and put the two bad ones on the EGR and intake flap.

2.5Turbo,

On my 1992, there are "only" 2 transducers Y31/1 (EGR) and Y31/5 (Wastegate).

There were 3 on 1990 and 1991.

Unfortunately, both of them were bad, plus bad electrical connection, so I couldn't do a swap+test drive.

My wastegate actuator works freely and holds constant vacuum (when applied with hand pump @ 700mbar vac) and so does the EGR valve.

I've just ordered the parts from the dealer:

Y31/1 and Y31/5 = MB # 000 545 0327 @ 168,60$ Can each.

Plastic electrical connector to above transducers = MB #011-545-7128 @3.11$ (need to order the inside metal female connectors separetely, but don't have parts #. Price is 2,42$ each!)

Intake flap actuator = MB # 603 090 1066 @ 298,00$ Can.

Hope this solves my problem.

Still happy I haven't yet spent a single $ in hiring a mechanics!

Bye

2.5Turbo · #10 03-26-2007, 04:40 PM

Quote:

Originally Posted by BigBen

2.5Turbo,

On my 1992, there are "only" 2 transducers Y31/1 (EGR) and Y31/5 (Wastegate).

There were 3 on 1990 and 1991.

Unfortunately, both of them were bad, plus bad electrical connection, so I couldn't do a swap+test drive.

My wastegate actuator works freely and holds constant vacuum (when applied with hand pump @ 700mbar vac) and so does the EGR valve.

I've just ordered the parts from the dealer:

Y31/1 and Y31/5 = MB # 000 545 0327 @ 168,60$ Can each.

Plastic electrical connector to above transducers = MB #011-545-7128 @3.11$ (need to order the inside metal female connectors separetely, but don't have parts #. Price is 2,42$ each!)

Intake flap actuator = MB # 603 090 1066 @ 298,00$ Can.

Hope this solves my problem.

Still happy I haven't yet spent a single $ in hiring a mechanics!

Bye

Right....it does. I haven't had the opportunity to work on a 92/93 2.5T so it must have slipped my mind at that late[r] hour. That price for the transducer sounds about right after the currency conversion. Makes me happy too that I was able to pinpoint and fix the problem without spending too much money at the indy. Even though these cars have that primitive computer, they still aren't too bad to work on contrary to popular belief on this forum. I'll gladly take the bit of added complexity for the smoothness, power, and fuel economy of the 602 in the excellent 124 chassis.

Can't wait for May to roll around so I can go home and drive her again

BigBen · #11 03-29-2007, 06:20 PM

Quote:

Originally Posted by BigBen

I've just ordered the parts from the dealer:

Y31/1 and Y31/5 = MB # 000 545 0327 @ 168,60$ Can each.

Plastic electrical connector to above transducers = MB #011-545-7128 @3.11$ (need to order the inside metal female connectors separetely, but don't have parts #. Price is 2,42$ each!)

Intake flap actuator = MB # 603 090 1066 @ 298,00$ Can.

Hope this solves my problem.

Ok. Done all that. Now, I have no boost whatsoever. Never.

So, my problem is different, there used to be some boost sometimes.

I will have to study vacuum and electrical diagrams.

My electrical connector on Y31/5 Wastegate vacuum transducer was destroyed and had poorly been repaired. Now that I have reinstalled a proper MB connector, I am starting to fear there may be reversed (I can't be 100% sure the PO had done this poor connection correctly).

Does it matter which wire connects to which terminal of the transducer?

I have to sort that out.

And btw, I'm not sure either the vacuum lines are properly connected.

More to come later on...

Thanks for any clues.

Bye

BigBen · #12 03-26-2007, 10:53 AM

Quote:

Originally Posted by ForcedInduction

transducer? codes? computer?????

I'm sure glad mine doesn't have any of that.

And I do dream about yours for sure. It's just unfortunate the old cars rust away in this part of the country with all the salts applied on our roads.

Working on "rod controlled" engines is so much easier for the DIYer!

I've just noticed your description of your car. Very nice!

Couldn't you inject your water/methanol mixture using an ALDA-like valve, that would add your cooling mixture proportionnally with boost? I've seen that in tractor pulling on the Redline Fever super-stock tractor (a International Harvester 1066)with a I6, 466cid and multiple turbos.

Bye for now,

BigBen · #13 03-30-2007, 05:12 PM

Great, I found my latest problem: I have inverted two vacuum lines on Y31/5, the vent ended up at OUT port and vice-versa. So the vacuum pump was having trouble maintaining proper vacuum since it was sucking air from open atmosphere through the vent!

And now, I HAVE BOOST ! So much more fun to drive!

I'll double check the codes in EDS later on and I will report here. But I think my major problem was the Intake Flap actuator: it was truely leaking and not moving the flap more than 1/2". Now I can see the flap move almost half a turn when increasing the rpm at idle. And the EDS can now "see" the reduction in air flow from the MAF, so it doesn't kick in limp mode.

So, it's my turn to thank you for taking some time in helping me with comments and suggestions.

Bye

BigBen · #14 04-01-2007, 11:11 AM

I did a few test runs 0-60 in the past couple of days.

I'm in the 16-17 sec range. I'm sure it can be better since I clearly notice a drop in boost under some circumstances. BUt don't get me wrong: this is already a major improvement over previous conditions (20+ sec).

But I will drive the car in real life conditions to become more familiar with its behavior and I will come back.

On another topic: I can confirm the Search feature here returns very valuable infos, it's a tool worth learning how to use (especially the Advanced Search options).

Bye,

BigBen · #15 04-01-2007, 09:18 PM

Quote:

Originally Posted by BigBen

In the order they appeared about in March 06:

15
8 B11/4 Coolant sensor
9 B2/1a Intake air temp.
2 L7 Fuel rack sensor
3 B2/1 Air flow sensor
11
5

Could anyone help with 15, 11 and 5?

And here are the readings today 1 April '07, after changing both vacuum transducers and Intake Flap actuator:

5
15 Y31/5 boost failure, vacuum transducer. I found this description in post #20 here: '93 300D 2.5T, 0-62 in 20 sec???

9 B2/1a Intake air temp.
2 L7 Fuel rack sensor
3 B2/1 Air flow sensor
11

I will search again to find out what 5, 15 and 11 mean and will edit this post to complete it.

I am thinking it could be an electrical problem with connectors or ground somewhere.

Any thoughts?

Bye