I am working on a ML 320 that will not shift out of firstgear, and the engine will not reveup until the rpms come back down to almost idle then it will engage and it will do this all over. The transferr case was empty, so I filled it with trans oil. Test drove the car in low range mode and it shifted as it is supposed to. Is this an electric problem or a mechanical problem ?

That truck as well as ALL MB's after 1997 use an electronic transmission.

Reading codes from trans computer is required for diagnosis.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

I took the car to autozone and their scanner gave a code p700 (faulty transmission controll moduel

where is the trans controll moduel located on the ML 320?

Doubt that is the problem!!

P0 700 is a generic "engine code" that suggests an issue with the trans.

Reading the code from the TRANS computer is the only way to know where the problem really stems from.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

I am trying to get the soft ware for my gennisys OTC scanner, do I need to get the cables also if i only want to get the codes from the trans, computer ? Thanks for your expertise.

You need to find a MB repair shop that has dedicated MB scanner to read those trans codes.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

do i need the round connecter to plug into the 1999 ml320 to read the transmission codes ?