I drove my 1997 C36 (115k miles) out to Indianapolis last week to catch the US Grand Prix; what a letdown that race was, but we still had a great time. We made the 650 mile trip in great time, at an average 65 mph that included a half-hour stop for lunch and gas. The car ran great the whole way, and I can't tell you how much fun it was to be like a shark tearing through schools of guppies for hours on end.

Anyway, the transmission began to act up soon after we arrived. The problem began as a lack of shifting - the transmission would work fine for a while, then give a lurch and stay in whatever gear it was at the time. At first, rebooting (turning the car off and then back on again) restored normal operation but the car eventually went into limp mode, locking in second gear.

It was a real pain in the ass, but we did manage to make it through all the local driving over the weekend. I knew there was no way I'd be able to drive the 650 miles home like that, so I took it to the local dealer (World Wide Motors) in Indianapolis for repair. I was very impressed with their customer service, but the diagnosis of a bad conductor plate ($720 total) seems to have missed the mark because it only lasted for about 300 miles into my journey home. Fortunately for me, I was running in fourth gear when it locked up and I did manage to nurse it home, carrying a 70 mph average and making the trip in 9:20 elapsed.

Can anyone offer any advice on what might be causing everyone to think that I got another bad conductor plate? What might be causing these indications? Is it possible that I did get another bad conductor plate? If it's not the conductor plate, what else could it be?

Best Regards,
Rob

__________________
Robert Fini

'12 ML350 BlueTec, 87k
'06 E320CDI, 270k
'05 T1N Sprinter 2500/Pleasure-Way Plateau TS, 69k
'97 C36AMG, 313k (son's)
'94 E320T, 249k
'93 190E Sportline LE, 168k (daughter's)
'84 190E-2.3/5spd (Stage Rally Racer)
'66 230 W110 Sedan (Barn Find, Vintage Racer build in progress)

If they're saying it is a bad condcutor plate again, then it should be replaced under warranty at no cost to you, seeing as how you bought it from a dealership. It's a "parts warranty" issue.
After that you may be looking at a control unit or valve body issue. I am assuming there was no visual evidence of wear/internal failure because they would have seen that and advised you when they (Indianapolis) pulled the valve body out the first time.
Also conductor plates are often replaced due to speed sensor faults. The speed sensors are integrated into the plate. I've often found codes for speed sensor faults when there is fluid in the control unit. Ask them to check for fluid contamination in the ETC unit, they shouldn't charge you to just check. Good luck.

So, my local dealer diagnosed the problem as another bad conductor plate after reading another #109 code for a faulty speed sensor. They replaced the plate that the Indianapolis dealer installed, under warranty at no cost to me (yah freaking hoo). My dealer tells me that it's as good as new and off I drive. I scoot the 40 or so miles home and it runs great - kicked ass like at always has.

Later THAT SAME DAMN NIGHT, the car once again locks in gear and eventually goes into Limp mode. It is now back at the dealer, and they're saying that it's looking like the entire transmission needs replacing. This is based on some test that they're performing that is supposed to return a value of something like 620 and my car is reading 8000. They'll do some more tests to confirm that it needs replacing, and my Assistant Service Manager has promised me that he'll go to bat for me with MBUSA to try to get some "goodwill" that his dealership can use to offset the estimated $4500 cost for a new transmission, if that is in fact the remedy for my troubles.

Can anybody tell me why a Mercedes-Benz that's nine years old with about 115k miles on it should be needing its third transmission?

Best Regards,
Rob

__________________
Robert Fini

'12 ML350 BlueTec, 87k
'06 E320CDI, 270k
'05 T1N Sprinter 2500/Pleasure-Way Plateau TS, 69k
'97 C36AMG, 313k (son's)
'94 E320T, 249k
'93 190E Sportline LE, 168k (daughter's)
'84 190E-2.3/5spd (Stage Rally Racer)
'66 230 W110 Sedan (Barn Find, Vintage Racer build in progress)

I am waiting for the day they want you to replace the whole car when a light bulb is out...

But seriously, it seems that the 5-speed transmissions isnīt that bullet proof as the 4-speed. I have 4-speed in my CE 36 with no problems (yet) ...

Those transmissions are well known for an O-ring leakage at the connector, soaking the connector plug in fluid. This will cause the faulty conductor plate code. I would pull the plug to see if it is wet with fluid before doing any more shot-in-the-dark repairs. During routine fluid replacement, this O-ring should be replaced.

__________________
'96 C280 (gone)
'97 C36
'05 C230k

I'm willing to bet the trans module is full of fluid- that will cause exactly what you are talking about- the conductor plate leaks past the pins , up the harness and into the module. Very rare that the trans would fail- especially intermitantly, if a clutch pack is burned up, or a seal blown out, they don't work ok sometimes...

What do those numbers represent, are they RPM sensor n2, n3 readings, Or adaptation limit values .Do you have a print out of the fault codes


if the 8000 RPM values are rpm readings, it’s an external electronic, wiring, plug problem. as said, check the TCM and transmission wire harness for transmission fluid

Ah, the "hydra electron realignment control." My understanding of this highly sophisticated software driven process is that the fluid is redirected to the control unit when the fluid becomes over saturated with disoriented electrons. With the power of software and high end electronic sensors the fluid is continuously monitored for confused electrons. Because the electrons roam freely in the non-conductive hydraulic oil they loose the ability to push each other around. In order for the electrons to become reoriented they must go through a realignment process inside the control unit. The fluid around the electrical connector is continuously monitored, when the oil reaches 1.2 kilofunk the fluid is redirected to the EGS/ETC control unit. The hydraulic fluid begins the neutralizing phase by simply collecting inside the specially designed plastic housing. When the neutralized fluid reaches the predetermined level inside of the housing the electron realignment process begins. During the electron realignment process any one, possibly all, of the following symptoms may be exhibited:

• Limp home mode
• Erratic or irregular shift patterns
• Implausible gear DTC’s
• Check engine MIL Illuminated
• Starter interuption

Once the electron realignment process begins you will need to:

• Repair fluid leak at the connector
• Drain the EGS/ETC control of the disoriented fluid
• Cleanse the electrical components
• Reset the electron aligners “Adaptation”
• Perform the “Adaptation Drive”

For EGS/ETC control units that are over saturated due to a faulty internal “level check COMode" circuit

• Repair fluid leak at the connector
• Replace the EGS/ETC control unit
• Reset the “Adaptation”
• Perform the “Adaptation Drive”

After returning from an “Adaptation Drive” please allow the vehicle to idle for 15 minutes. During this time final calcualtions are being made in order to generate future failures.

This article was written with a large amount of fecal matter in order to make you laugh. If you are laughing then I will assume it worked, if not...................oh well

Have good day folks......

Thanks for the attempt at humor, MrCjames, but I'm really not in the mood right now. The only saving grace on this whole bull**** episode is the really fantastic service loaner they gave me - brand new C280 4matic with a killer sound system, with Mars Red exterior. I'm almost willing to tell them to keep the C36 if I can keep the C280.

Anyway, the only fault code I'm aware of is the #109, and I do not know what the units are on that 620/8000 reading, nor do I know what test those results represent. I do not have any kind of readout or other documentation - all my correspondence with the Assistant Service Manager (ASM) has been via telephone. I did discuss the TSB regarding the modifications to the connector and possibility of fluid seepage with the ASM, and he did say that they checked for fluid in the module housing and found none, also that they Ohmed out the wiring harness to confirm connectivity through the harness. I do expect to talk to him tomorrow, so I'll see if I can press him for further details.

I agree that it's an electronics issue and unlikely to be an internal transmission problem, since it's okay for a while and then isn't. Thank you all for your suggestions and stay tuned...

Best Regards,
Rob

__________________
Robert Fini

'12 ML350 BlueTec, 87k
'06 E320CDI, 270k
'05 T1N Sprinter 2500/Pleasure-Way Plateau TS, 69k
'97 C36AMG, 313k (son's)
'94 E320T, 249k
'93 190E Sportline LE, 168k (daughter's)
'84 190E-2.3/5spd (Stage Rally Racer)
'66 230 W110 Sedan (Barn Find, Vintage Racer build in progress)

Please excuse my feeble attempt at adding a touch of sarcastic humor to the all too common problem with the 722.6 transmission(s). I am sorry you are having difficulties with your transmission however sometimes the repair is simply a matter of time. It requires time to properly diagnose the underlying or ongoing issue. It requires the technician to get paid fairly for his time when diagnosing a menacing computer and or electrical related problem. When the manufacturer and or the vehicle owner is less than willing to fairly compensate the electrically skilled technicians for their time then the results are less than favorable.

I have little doubt that eventually your transmission problem will get resolved. This will occur when someone decides to devote the time to diagnose the "complaint" to identify the "cause" and then make the needed "correction." The shift quality of your transmission will also greatly improve when the required time to properly perform the “Adaptation Drive” is done as per Mercedes Benz repair instructions. In total I would speculate that a fair labor time for “Diagnosing” and then “Repairing” most transmission related complaints (excluding the replacement of the transmission) would be in the neighborhood of 5 hours (+/- 1.0)

i know that the clk class cars had a problem with trans fluid climbing up the wiring from the trans into the trans computer.if this is also the case with the c class then maybe you should have someone take a look.it's cheaper than a new trans and exactly the same symptoms.david poole european performance dallas tx.

So, I finally got the car back from my local dealer, after nearly two GLORIOUS weeks with that Mars Red C280 4MATIC. What a sweet little piece of tail that thing is! It's got me seriously thinking of giving up on the C36 and going for a new C350 Sport Sedan in Mars Red with the six-speed manual transmission. I'd get the split-folding rear seats and the roof rack for cargo capacity, and of course include heated seats like all real cars must have. It's only two-tenths of a second slower to 60 than my C36, and boy-oh-boy is it SEXY! Mmmmm....

Anyway, they had three different gizmos hooked up to various electronic orifices on my car for more than a week, and couldn't get the problem to repeat itself so they could document and measure it. I gave my permission for the shop foreman to take the car home for the weekend, and he apparently beat the living crap out of it until the problem resurfaced (I can't fault him because that's what I told the Assistant Service Manager he'd have to do). FINALLY!

So here it is....

The cover plate on the false floor where the transmission control module lives had been chafing against the feed wire from the vehicle speed sensor long enough to cut through the insulation. Intermittent contact between the cable's inner conductor and the grounded floor plate caused the control module to read a faulty sensor, which apparently is an indication for a failed conductor plate. I just picked the car up tonight and the problem has yet to resurface after probably 50 miles of driving, so we do not yet have definitive proof that the problem is resolved.

Supposing it is gone and we're "good as new," the troubleshooting process for such a complicated electronic system that was used by BOTH factory-authorized dealers seems to me to be suspect. Yes, I'll admit that an intermittently shorting conductor is a real ***** to diagnose and locate, but I have always begun at the sensor and worked my way back to the processor whenever trying to debug my own designs and creations. And I won't even mention the fact that this control module was installed about a year ago by my local dealer, whose technicians didn't seem to pay particular attention to the routing of the cable harness after they were finished with their work.

Any and all comments are most welcome at this point, especially in regards to making the jump from the C36 to the C350. Thank you all for your interest and I appreciate your attention.

Best Regards,
Rob

__________________
Robert Fini

'12 ML350 BlueTec, 87k
'06 E320CDI, 270k
'05 T1N Sprinter 2500/Pleasure-Way Plateau TS, 69k
'97 C36AMG, 313k (son's)
'94 E320T, 249k
'93 190E Sportline LE, 168k (daughter's)
'84 190E-2.3/5spd (Stage Rally Racer)
'66 230 W110 Sedan (Barn Find, Vintage Racer build in progress)