I hope someone can help me..
I have a 98 ML320 that is about to kill me.
Awhile back the car would go into limp home mode after running and was at operating temps, especially after stopping. Then it would clear and run OK after it cooled.
I read the codes in the OBD and it gave me p0700 trans control failure.
I removed the TCU and cleaned up the connections and was able to get the problem cleared (no Codes or CEL) then the unit failed again and I was not able to get it working again. Still has P0700 and then P1747 (can failure) I was able to find a direct replacement (same numbers) and installed the unit. And this is where I am today.
I still get a P0700 code, and now I dont have the Park interlock or reverse interlock. I have been trying to determine if there is either a fuse or any overload protection for the TCU and where it is located. I do not have a wiring diagram and have hit a dead end.
Any help would be appreciated. Thanks

The trans ECU is above the gas pedal.

WHY not read codes from ALL of the powertrain computers? not just the engine computer. Codes locked in the trans computer OR transfer case computer WILL cause engine codes until they are ERASED.

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Are these read at the dealer only?
I have an appointment with the dealer to take it in and have the replacement TCM programmed to the truck, I hope that this will correct the problems and get it back on the road again.
Do you have any idea why the park and reverse interlocks would quit working?? Are these controlled by the TCM?
Thanks for your help!

Hi,
I'm not a technician, but my ML320 was doing this, especially in hot weather. No dealer could find anything wrong, and they were all really trying. There were no codes or anything. A friend suggested that it could be the fuel pump in the GAS TANK,(yes, there is a second one!). The local repair guys replaced it (it's a lot of work), but I have had no problems since, even in 115 degree heat going up hill.
Just a thought.

My 2000 320 CLK instrument cluster was intermittent, then completely blank, then comes back. The fault code was P1747; Electronic Gear Selector Module: Defective Interaction of CAN with control unit A1(instrument cluster). I'm reading that the the CAN can be replaced (direct replacement-same numbers). How can I determine what the correct CAN is and is it difficult to replace?

I had the problem on a trip to California last fall and it continues. When ambient temp is above 104 F my 2000 320 ML went into limp home mode and decelerated fast. Moving the shift lever into neutral and gassing it confirmed engine fuel supply, returning to Drive, it picked back up like normal. As the temp went higher (up to 109 near Yuma) the problem repeated more often. Stopped in San Diego at MB dealer. Absolutely No codes! worked with team of 4 there and the MB world database on problem. Concensus was probable mechanical, heat related fault in Transmission Conductor Plate.

After replacing TCP, no further problem - until I approached Amarillo TX on the return - ambient temp 104 F; problem repeated.

No further problems until last week when it was 107 in Dallas - had 3 more events until temp dropped below 104 F

Will check out the Fuel Pump approach, Thanks!