Bowyer

My daughter has been using my 2002 e430 (226k miles) for several weeks. Informed me the 'car isn't running right, and the CEL is on.' I drive it and it's stuck in low gear....limp mode I assume. Pulled coeds and got 071, 0174 and 0702. The first two are car is running lean....but the 0702 code is what concerns me as it appears to be what is keeping the car from shifting. I can't reset that code with my reader. Conductor plate and bushing were replaced 4 years ago. Can the code be reset without a trip to the dealer or indy shop? Any thoughts? Anything I can do at home to diagnose?

Also, my battery is 6 years old.....could changing to a new one help, or can a bad battery lead to this code? Haven't had any electrical issues, but I do know it's time for a change of battery. Just wondering if that could rectify the situation and get the car shifting properly. Daughter is not happy at the moment as it is Saturday and she can't go anywhere.

Thanks for any help you can provide.

kajtek1

What scanner did you use?
It takes top-end scanner to reset transmission code.
Do some forum search >>> https://mbworld.org/forums/s-class-w...e-w-p0702.html
Sounds like battery test and new pilot bushing are easy start on the issue.

Bowyer

Thanks kajtek1. I replaced the battery...it was shorwng old according to Auto Zone and my multi meter tests. No change....no CEL, but still in limp mode. I didn't see and drips from the transplug. It was replaced a few years ago along with the conductor plate. Do the new adapter plugs go bad? Any way to get it out of limp mode without STAR machine?

kajtek1

Again, you need top-end scanner to reset transmission code.
Just becouse you don't see ATF dripping outside, doesn't mean it did not sipp into plug connectors and way up to TCM

Bowyer

Thanks...I will check the TCU for fluid tomorrow. I'd like to figure out if it is the shifter control (possible spill?...daughter drives it so there is no telling. She says no to a spill) What's a better scanner/reset tool for Mercedes? Do they make one that checks and clears the different systems? I'd likely need to have the car towed since I am far from a dealer or an independent garage.

kajtek1

Getting advanced scanner with 38 pins for W210 is a bit tricky.
I no longer own car with 38 pins and have couple of $150 OBD scanners that can reset transmission, but on one by one condition.
I know MaxiEcu makes designated W210 scanner, but shipping from Poland will take some time.
Go to benzworld and seek member handle MAVA. He is expert in rebuilding those transmissions and shares his knowledge there.
The same 5G transmissions were used in most of MB of the era, so the knowledge is spread over several sections.

Bowyer

One last question, kajtek1. I can't seem to register on the other site...password issues.

I went to the dealer and bought new conductor plate...figured it had 100k miles and couldn't hurt. Talked to a tech there who said 95% certain the 0702 code would be a speed sensor in the plate. So, I changed the shifter and the conductor plate, but the code is still there and same symptoms. Tech seemed to think that once the conductor plate was changed, and the issue (if it was the speed sensor), the code would go away. It didn't.

So now I will tow the car (too far to limp) to an indy shop who has the correct scanner to reset codes. If the problem was in the plate or shifter, just resetting the code should fix it at this point, correct?

Thanks

bbirdwell

You have to use STAR to clear the error code in the TCU after replacing the conductor plate.

fabbrisd1

If I have missed it - FRESH tranny adapter plug (MB or MOPAR only) - and pull TCM and with can of MAF spray flood/clean the TCM board - THEN have code reset

Bowyer

Thanks. I was hoping it would correct itself, haha. Good news is it should be good to go once the code gets cleared at the shop. Too bad MB keeps it so locked down for the DIY-er.

Bowyer

OK, thought I would add some closure to this thread, since the car is fixed. I changed the conductor plate, same p0702 code (you HAVE to have a STAR reader of something comparable to reset this...as I learned, otherwise, car will remain in limp mode).

I did notice that when I unplugged the electrical connected to the conductor plate, there was water...quite a bit, that drained out of the electrical connector. I have a feeling that may have been the issue all along. I drained the water and sprayed electrical contact cleaner in the plug before reinstalling. Happy to report there was no metal in the pan when I drained and dropped it.

Has anyone ever had WATER (not trans fluid) in this connector...and did it cause a code to pop up? My car is missing the splash shield/belly pan which may have exposed it to road water. I did wrap the harness with electrical tape to prevent water from getting in there in the future.

Thank you all for your advice...and to reiterate, you NEED a good reader that plugs into the round connector on the driver's side fuse box in the engine bay to clear the P0702 code!