E300D - need help - Page 2 - PeachParts Mercedes-Benz Forum

sokoloff · #16 05-07-2024, 05:47 PM

Took the car out today for a short ten mile drive to see how things were. Other than the check engine light being on, things were pretty normal Car didn't overheat or even tend in that direction even though it was a very short trip. The transmission shifting felt pretty normal. So my next step will be to run it by one of the parts stores and have them read the codes for me. I suspect that they will only have to routine OBD code reader and not the unit that connects to the 38 pin unit under the hood. But at least that will be a start.

engatwork · #17 05-07-2024, 07:28 PM

Call Jim's Car Care on Ocean Blvd and ask him how much to read code.

sokoloff · #18 05-08-2024, 01:23 AM

engatwork - thanks - Jim's is only a few miles up the road.

sokoloff · #19 05-08-2024, 08:56 AM

So here's the big question - I know where the 38 pin connector is, but is there also the standard OBD connector somewhere? I don't recall every using it on this car. I looked under the dash where the OBD connector is on my other cars and I sure didn't see it at first glance.

Benzadream · #20 05-08-2024, 09:15 AM

The OBDII should be under there.....somewhere.
The issue with the 16 pin OBDII port, should you find it, is that it supplies only a limited amount of data/information. I can't be certain, but it may only access engine data....not sure. In order to interrogate a larger number of the car's systems, you'll need the 38 pin, under hood connector, and a scan tool capable of interrogating all that's available. As well as bidirectional control, module activation, etc.

engatwork · #21 05-08-2024, 02:47 PM

It is there. Look over towards drivers side under dash area where your legs/feet are usually at.

That is correct regarding what the OBD port and the 38 pins connector will tell you. OBD just the engine stuff.

engatwork · #22 05-08-2024, 02:48 PM

It is there. Look over towards drivers side under dash area where your legs/feet are usually at. IIRC there is a little door/cover over it.

That is correct regarding what the OBD port and the 38 pins connector will tell you. OBD just the engine stuff.

sokoloff · #23 05-08-2024, 04:27 PM

Got it - thank you. Not the easiest to access. Guess this is how they did it in the "old" days. Yep, two screws holding the "door" in place.

sokoloff · #24 05-20-2024, 12:46 AM

Car seems to be behaving normally on the few short test drives I've made. Transmission is shifting as it should and there is no evidence of the car overheating.
Today I was finally able to get the OBD codes read. Interestingly enough the check engine light went off as I was driving to get the codes read. There was one stored code - P0715. I think that points to the transmission conductor plate? After watching a few videos of replacing the conductor plate, it sure looks like it is not a DIY job for me without a lift in my garage.
So my thoughts now are to just drive the car and see if the problem occurs again. Maybe I should drive the car more than once every two months like I have been and give the car exercise and allow the various fluids to get where they need to.
Suggestions/comments welcomed.

jdulle · #25 05-20-2024, 07:30 AM

I'd just keep driving it and see if the code comes back.

engatwork · #26 05-20-2024, 07:31 AM

Quote:

Maybe I should drive the car more than once every two months

Good idea.

sokoloff · #27 06-28-2024, 10:13 AM

Well, a not too satisfying update. As my last post said, a month ago I finished up the two year service and did a few short test drives and all seemed okay. However, I did nothing during that service to address the transmission issue. The check engine light was off but the stored code seemed to point me toward the conductor plate.

Ten years ago I would attack and replace the conductor plate myself, but that job is too much for me to do these days without a lift. So do I have the conductor plate job done for well over a thousand bucks or do I just sell the 25 year old car that I've over maintained and really like?

Yesterday I took the first "longish" drive expected to be an hour. After about a half an hour the transmission went back to being the same problem child and wouldn't shift out of third. The car also minimally started to run a little hotter than usual, i.e. just above the 80 degree number. It usually stays locked in at just below the 80 degree number. I made it home with no problems, but things need to be addressed.

As a side note and what I think is unrelated my parking lights and low beams were on and would not shut off. That little green light next to the headlight switch that indicates that the foglights and/or side marker lights are on was lit. That light should only go on AFAIK when that switch is pulled out. However, it was not pulled out and no matter what the position of the light switch was in, the lights remained on. I disconnected the battery to keep them off. This morning out of hope, I hooked up the battery again and same thing happened. Lights were still on and no playing with the switch did anything?

Skid Row Joe · #28 07-04-2024, 11:12 PM

Quote:

Originally Posted by Benzadream

Greetings from another "senior" who's no stranger to those "moments", too. I have a '97 E300D with about 155k on the odo. Mine has also been a great car. However, I did have a few issues similar to yours earlier in my ownership. Once those were addressed its been good.
Unfortunately, the climate control display will only display data/values related to the climate control system. Still, a really GREAT feature and also an absolutely wonderful climate control system.
Re: Transmission problem. Has your trans fluid/filter ever been changed? I ask because MB claimed this car's transmission is "sealed for life" and never needs fluid or anything else...I guess? That sales pitch was a bunch of bs and that type of transmission hasn't been invented, yet imho. Not sure about your year, but mine didn't even have a trans dip stick! Had to buy one, not expensive and easy to find.
I'd start there, for sure. BTW, my "sealed for life" transmission fluid resembled used motor oil except it was dark green in color.
Another issue I was having was gear selection, like yours. The part needed was the "gear selector recognition control unit". About $100, easy to find (a bit of a pain to install). It lives in the gear shift selector and is what "lights up" when you put the shifter in the various detents (P R D 2 3, etc). The way to check its function is to make sure when you select a gear or neutral and even "park", that the selection is "lighted". Hard to see in sunlight, much easier at night.
I originally thought those were illuminated only to see them at night. That is incorrect.
Look up the part and you'll see what it does. It's actually part of the auto trans shift logic.
I'll stop there, for now, and wait to hear back from you. This little bit of maint/trouble shooting could go on and on.....
In closing, when was the last time your coolant and thermostat were changed?

Quote:

Originally Posted by sokoloff

Interesting info - thanks. I don't recall ever seeing that this transmission was "sealed for life." I also don't see a transmission service being listed on the service sheet. Anyway I've serviced the transmission a few times, the last one being in 2016, i.e. 20,000 miles ago. That means fluid, filer, torque converter and gasket. I had a note to myself to do it again in 2025 or 2026. That could change depending of where this all goes.
That "gear selector" issue you had is interesting. I'll have to look at mine, but I think the gears were lit up like they were supposed to be.
Coolant done in 2020 (7000 miles ago) using a five year coolant, so that's on tap for 2025 or 2026 too.
Keep those suggestions coming. I've got to figure out how/where to get a fault code read without driving the car very far.

RE: gear shift selector assembly

My (formerly owned, now my brother owns it.....) '99 E300TD's gear selector shift is sloppy - Left & Right in Drive. It easily goes right to lock out 5th gear if easily pushed there inadvertently. (Something's well worn)

The question is; Is the sloppiness/play related to the gear shift selector assy. that includes the lighted selection?
Or, is it the round clear plastic round shift spool/s located lower in the shift underneath the car that needs replacing?

.

sokoloff · #29 08-06-2024, 04:41 PM

Well it took me awhile to get the car in to a Mercedes specialist to figure things out.

He checked the codes on the 38 pin connector and only found one - the speed sensor. He cleared it. As I noted in my posts above, I was having transmission problems where the transmission would not shift into fourth gear lots of times. Then just before I took the car in for this service, the headlights and tail lights would not turn off and the little green indicator for the side marker light would not go out even when the car was off and the key was removed. I had to disconnect the battery to save it from discharging. And finally the driver's side window would not go up or down. Those things can't all be related, can they?

Well it turns out that replacing the speed sensor fixed everything I think. The mechanic showed me the old speed sensor and it actually had the plastic case starting to melt. The mechanic said it was actually smoking.

So I've only driven the car 30 miles home and have had it in my possession for only a couple of hours, but so far things are looking good The only thing I need to check is I don't think the headlight dash light is working. The high beam indicator next to it works.

So is it possible that the speed sensor controls all of these things?

engatwork · #30 08-06-2024, 05:46 PM

Sounds like it was the culprit.