Oxygen sensor connector - where ???

[chrisro]

Welcome all!
I have 01/1992 500E. I just imported from UAE. Many things need to be sorted after not professional service and reppairs.
First of all is oxygen sensor which hangs not connected near cat. In floor there is a rubber instead of connector. I can not see any wires going inside car. Also in ecu there is no error related to Oxygen sensor. There is only one about HFM sensor which is I pressume Air flow sensor - I suspected is broken coz car is starting really hard when cold.
Was every 500E equiped with cat.converters? If yes there was always oxygen sensor? I suspect that somebody just fitted cat. from newer model and Lambda is not connected now as was not from factory. That is why I don't have any faults in ecu?
Please help. Thanks
Chris
Poland

[samiam44]

Congrads on the new car Chris,

It might be helpful to share the vin and that will tell us where the car was originally delievered and it's configuration.
Yes, I believe there were non-Kat cars delievered in some countries.

Michael

[gsxr]

samiam is correct, some early 500E's were available without catalyst. You'll need to provide the VIN so we can confirm if it came with or without cats.

If it did have cats, there will be a plastic connector on the side of the transmission tunnel, very close to where the O2 sensor is located.

Also - what part number is the LH module? Remove the cover on the CAN box (under the hood, passenger side, near windshield) and you can read the p/n's of all the modules.

Welcome to the forum!

[chrisro]

Thanks for quick reply!

VIN = WDB1240361B694312

ecu number is 010-545-00-32

[gsxr]

Hmmm. I can't tell for sure if the car originally came with a catalyst, there's nothing obvious in the datacard:
https://www.datamb.com/vin/xNb8kEQjxNB2RZ4yo

The ECU is a very early unit, possibly dated 1990 or very early 1991, which is unusual since your car was built in early 1992. And, the ECU is designed for use with catalyst, so it should have an error code present if the O2 sensor is disconnected.

What are you using to check fault codes?

[chrisro]

Thanks for an answer.
I use Launch x431 good older unit.
It showed my good faults i.e. air temp sensor broken, replaced and working.

Strange is that Mercedes from Germany is writting me also that it came with g-cats from factory Euro2.
But on a side of tunel like I said is rubber plug and under I see white plastic from tunel.
Does somebody has a picture of o2 sensor connector under car? To define if I am looking ok?
I try this evening to make picture under my car.

Ecu is 90M12. Blue dot and K04 on it.
Is vin coded in ecu?
Maybe somebody changed ecu later on.

[gsxr]

The ECU may have been replaced at some point, but the one you have should work ok... they are not VIN coded. If your Launch scanner shows live data, check the adaptation values on the LH module. Upper & lower should usually be within 10% of mean (0.9xxx or 1.0xxx) if everything is relatively normal.

The O2 sensor female connector on the body is part number 140-540-03-81, only the round portion pokes through to the driveshaft area. It will be on the passenger side to the rear of the transmission.

I have a photo somewhere but I can't find it at the moment.

[chrisro]

Here is my lambda and rubber plug

[gsxr]

Here is my lambda and rubber plug

That is where the connector should be. Next thing to do is pull the carpet inside the car and look for wiring/connectors inside, to see if anyone disconnected it and plugged the hole?

Very strange!

[chrisro]

Photo inside attached. You can clear see that it was like this from factory I think.
Also photo of my modules - on LH is K04 maybe this is footnote - not for use with catalyst?
Now I am confused. In papers there is cat but no oxygen sensor? Possible?

[gsxr]

Hmmm, that does appear to be factory.

Two of your CAN modules are probably not original; in addition to the LH module being unusually early date code, the E-GAS module is dated almost a year after the production date. The "Kxx" number indicates the software/firmware revision of the module, it is not related to the catalyst. Footnotes only exist in the EPC (Electronic Parts Catalog).

Another item to look at is the LH trim plug, located behind the CAN box. This is only present on Euro vehicles. Cars with catalyst have knobs marked "KAT", non-catalyst are marked "ECE". See what yours says. Photos attached.

[chrisro]

It is marked KAT

omg

[gsxr]

Well now you really have a mystery! A car with the KAT trim plug, should have catalysts... but where did your wiring go?

[chrisro]

Cat. is in. I think to save money on taxes probably now is better to do just a wiring loom from oxygen sensor to ecu and change ecu anyway. Where I can find ecu pinout to connect proper sensor?

[gsxr]

Cat. is in. I think to save money on taxes probably now is better to do just a wiring loom from oxygen sensor to ecu and change ecu anyway. Where I can find ecu pinout to connect proper sensor?

See attached PDF file, page 3. First, see if there are metal pins in the sockets in the connector below the module, for the appropriate pins. Looks like assorted pins between 9 and 16.

[chrisro]

ThANKS a lot!
So I don't have pins 9-16 exept 13 sensor insulation.
My eeprom is 2 287 355 984 in ecu.
Does anybody has one from car with cat?

[gsxr]

EPC footnotes indicate ECU 010-545-00-32 should be compatible with catalysts. It's odd there are no fault codes on the module, also odd the wiring seems to be missing.

When you use the digital scanner to display ECU information (control module version), what does it show below country version? TWC (catalyst), or non-TWC (non-cat)?

I don't know what EPROM p/n is normally in that ECU. I've never had one to experiment with.

Another PDF is attached, which shows the factory procedure to convert a catalyst car to NON-catalyst. Probably won't help much since you are trying to do the opposite.

[e500.org]

Hi do you have any pictures or further details of the car? I'm in the UAE and it's a pretty small E500E community so may know the previous owner and be able to provide some answers.

[Eno]

There is a lot of “interference” or how can I say removal of parts or kats in the GCC cars.
But, since the car was a GCC delivery maybe it was delivered without it, who knows???



Sent from my iPhone using Tapatalk Pro

[chrisro]

Thanks for all infos.
Is it possible to just recode my ecu to be used with cats? I.e. with dealer equipment?
There are any other differences between cat and non cat cars?
W140 conversion manual is saying about Coils change and so on.
What I also don't have is airpump.

[gsxr]

Thanks for all infos. Is it possible to just recode my ecu to be used with cats? I.e. with dealer equipment? There are any other differences between cat and non cat cars?

No, it is not possible to "recode" the ECU. Version coding didn't become possible until the late 90's and early 00's. The KAT-delete document indicates it's fine to use an even newer LH module. I'm not certain what "tells" the LH that there is no catalyst. Did you check the ECU information displayed in live data as I described in post #17? If it already says "non-TWC", you can just leave everything alone. Having the cats present won't hurt anything (if the are not clogged).

W140 conversion manual is saying about Coils change and so on.

Coil change is only for very, VERY early build cars... the document is saying to upgrade to the newer version, which your car should have from the factory.

What I also don't have is airpump.

If you do a full catalyst install, you'll need the airpump too. Seems like either your car really didn't have the cats when new, or someone did most of a catalyst delete, leaving only the KAT trim plug?

[chrisro]

I did not passed emission control. I don't know if because of o2 sensor not working or Air Flow Meter not working. That is why I am thinking to connect Lambda.
My diagnostic tool is showing only:
hardware: 13/90
software: 45/90
Program status: 26
Data status: 27

Now I discovered that I do have airpump with cable flying near washer bottle. Where the cable goes?

Another question is what for is valve near washer on fender mounting? I discovered broken rubber.

Thanks!

[gsxr]

Airpump electrical connection is at the passenger fender, behind the headlight, difficult to access. The air pump usually only runs with the engine cold, to help burn off the rich mixture during a cold start. It rarely operates with the engine warmed up.

The 2 vacuum solenoids are for the EGR, and for the air pump check valve.

Your diagnostic tool should have a second page of information after the HW/SW and program/data status. Can you scroll to a second screen?

[chrisro]

My diagnostic tool don't display any other info.

Where is Co potentiometer in 500E ?

[gsxr]

My diagnostic tool don't display any other info.

Where is Co potentiometer in 500E ?

I don't know the Euro models very well, but AFAIK there is only one potentiometer for all systems, the one shown in the photo in post #11. If there's another, I don't know where it's located.

Maybe a member with a Euro-spec car can help out?

[chrisro]

Thanks.
I discovered now that I have EZL trim no.6

[gsxr]

Thanks.
I discovered now that I have EZL trim no.6

Green #6 #2 EZL trim plug is the "normal" one for catalyst cars.

White #2 #6 is for non-catalyst.

[chrisro]

Green #6 EZL trim plug is the "normal" one for catalyst cars.

White #2 is for non-catalyst.

I think you mixed
6 is white non cat
2 is green for cat

Does somebody have a pinout of oxygen sensor connector?

[gsxr]

Yes - you are correct, I got the numbers backwards! Sorry about that...

[gerryvz]

I’ll double up on the Yelmerian Award for GSXR.

I almost said something as I’ve really not seen too many 6 EZL resistors in my life.

[chrisro]

Hello all,
small update. I just bought ecu 012 545 6232. This ecu as well don't throw any fault code regarding O2 sensor. How is possible?
Is it normal?
Thanks

[chrisro]

Hello
so finally my story is over with happy end. I managed the conversion from non-cat to cat. I am still not sure if car was from factory with cats. However I made new loom from ecu to oxygen connector, changed ecu /with old one o2 sensor was still not working/, changed ezl cap and all is working fine. Emission test passed today with 0.05% CO instead of 2.64%. You can smell the difference!
Now is Time to register car and enjoy it. Thanks all for help.

Btw. My old ecu and ezl cap no.6 are for sale if somebody wants to remove cats.

[gerryvz]

Btw. My old ecu and ezl cap no.6 are for sale if somebody wants to remove cats.

Awesome news !!

You should start a new thread in the “Parts for Sale” section with your non-Catalyst goodies.

Cheers,
Gerry