transmission communication?
Thread Starter
Senior Member
Joined: Oct 2015
Posts: 397
Likes: 23
From: Queensalnd Australia
2006 ML320 CDI (2 of) and 2008 GL320
transmission communication?
I have a 2006 ML320 transmission which is playing up. Has 200,000 km on it (120,000 mile). Australian car.
Initially it seemed to have issues going 2nd to 3rd (surge, flare etc), I did a drain, cleaned the valve body, new filter etc - now the issue seems to be changing 4th to 5th, and sometimes it starts reverse in high, not reverse low.
The filter was cut open and it was clean, very little material on the magnets etc.
I don't get any codes from the transmission, using a Snapon Solus pro.
When I had the pan and controller off I noticed that the 5 pin plug only has 4 pins connected. The pin 3, opposite the "normally vacant" is missing on the car end. I looked back into the harness as far as I can see and there doesn't seem to be a 5th wire (just incase the pin had got pushed out of the plug).
According to the ATSG guide on the 722.9 this is the "diagnostic line".
Is this pin normally used in the ML320?, is that why I am not getting any codes?
The reverse selection only seems to happen say one in 20 times, and the rough 4th to 5th change is only at low speed - say 50kph. When the car is only gently going up through the gears.
if the car is under more throttle it seems to behave better.
Car is only doing about 1100 rpm when it is in 5th. At present I am manually locking it into 4th until it gets out of the city speed limits. It seems to be a low rev issue.
I was thinking that the speed sensors could be an issue but the lack of codes through me.
Initially it seemed to have issues going 2nd to 3rd (surge, flare etc), I did a drain, cleaned the valve body, new filter etc - now the issue seems to be changing 4th to 5th, and sometimes it starts reverse in high, not reverse low.
The filter was cut open and it was clean, very little material on the magnets etc.
I don't get any codes from the transmission, using a Snapon Solus pro.
When I had the pan and controller off I noticed that the 5 pin plug only has 4 pins connected. The pin 3, opposite the "normally vacant" is missing on the car end. I looked back into the harness as far as I can see and there doesn't seem to be a 5th wire (just incase the pin had got pushed out of the plug).
According to the ATSG guide on the 722.9 this is the "diagnostic line".
Is this pin normally used in the ML320?, is that why I am not getting any codes?
The reverse selection only seems to happen say one in 20 times, and the rough 4th to 5th change is only at low speed - say 50kph. When the car is only gently going up through the gears.
if the car is under more throttle it seems to behave better.
Car is only doing about 1100 rpm when it is in 5th. At present I am manually locking it into 4th until it gets out of the city speed limits. It seems to be a low rev issue.
I was thinking that the speed sensors could be an issue but the lack of codes through me.
Thread Starter
Senior Member
Joined: Oct 2015
Posts: 397
Likes: 23
From: Queensalnd Australia
2006 ML320 CDI (2 of) and 2008 GL320
Thread Starter
Senior Member
Joined: Oct 2015
Posts: 397
Likes: 23
From: Queensalnd Australia
2006 ML320 CDI (2 of) and 2008 GL320
[QUOTE=Plutoe;6921969]
Thanks again Plutoe, much appreciated.
Is this common with the USA version?, I am wondering if my Snapon Solus Pro Scanner is not finding codes because its looking in the wrong place.
I will look into what other models the scanner can look for and see if I get transmission codes.
Sorry about delay - away with work.
VIN WDC1641222A123165
All I can do is confirm your observations and that is only four pins are used(by your VIN) on the five pin connector, they are 1245. Pins 1 and 2 are the CAN pins, 1 is high and 2 is low. Pin 4 is to the front fuse and realy box and pin 5 goes to transmission circuit 31
And as you know the 722.9xx has the VGS control unit built into the conductor plate
VIN WDC1641222A123165
All I can do is confirm your observations and that is only four pins are used(by your VIN) on the five pin connector, they are 1245. Pins 1 and 2 are the CAN pins, 1 is high and 2 is low. Pin 4 is to the front fuse and realy box and pin 5 goes to transmission circuit 31
And as you know the 722.9xx has the VGS control unit built into the conductor plate
Is this common with the USA version?, I am wondering if my Snapon Solus Pro Scanner is not finding codes because its looking in the wrong place.
I will look into what other models the scanner can look for and see if I get transmission codes.
Senior Member
Joined: Aug 2017
Posts: 396
Likes: 11
From: Ontario, Canada
2006 ML500, 2008 ML350
[QUOTE=Plutoe;6921969]
Sorry for reviving an old post. Could "no com" be caused by a faulty Front Fuse Box by any chance. Thanks
Sorry about delay - away with work.
VIN WDC1641222A123165
All I can do is confirm your observations and that is only four pins are used(by your VIN) on the five pin connector, they are 1245. Pins 1 and 2 are the CAN pins, 1 is high and 2 is low. Pin 4 is to the front fuse and realy box and pin 5 goes to transmission circuit 31
And as you know the 722.9xx has the VGS control unit built into the conductor plate
VIN WDC1641222A123165
All I can do is confirm your observations and that is only four pins are used(by your VIN) on the five pin connector, they are 1245. Pins 1 and 2 are the CAN pins, 1 is high and 2 is low. Pin 4 is to the front fuse and realy box and pin 5 goes to transmission circuit 31
And as you know the 722.9xx has the VGS control unit built into the conductor plate
Thread Starter
Senior Member
Joined: Oct 2015
Posts: 397
Likes: 23
From: Queensalnd Australia
2006 ML320 CDI (2 of) and 2008 GL320
