Dear All,
Hello. My name is Michael. I am posting from Cyprus.
I am planning to do an extensive conversion on a Mercedes-Benz G-Class (1985 280GE LWB), including the installation of an MB M104 inline-6 3.2l, 24v engine coupled to an MB 722.6 5-speed automatic transmission.
My plan is to use the MegaSquirt MSIII (v3.57) + MS3X for the engine control and the GPIO – MegaShift for the transmission control.
I have done a lot of research on both the engine and the transmission but I still have a lot more things to do.
The Mercedes-Benz 722.6 (or NAG1 for Neue Automatikgetriebe 1) transmission is an electronically controlled gearbox mated to a lock-up clutch equipped torque converter. It first appeared in the mid-90s and has been in use on Mercedes-Benz passenger cars and vans ever since. Its’ variants also found their way into Jaguar, Porsche and Chrysler/Jeep/Dodge cars. Some of the transmission variants can handle up to 900 Nm of torque ex-works.
I have managed to gather the following technical information for the variant 722.611 (W5A330) which is rated at 330 Nm of input torque:
Ratios:
1st Gear 3.93
2nd Gear 2.41
3rd Gear 1.49
4th Gear 1.00
5th Gear 0.83
Reverse Gear 1 -3.10
Reverse Gear 2 -1.90
Electrical Connections:
The transmission bears a 13-pin electrical connector with which it is controlled. The wires are 0.8 mm in diameter (20 gauge). Pin 5 on the connector is not used, so there are 12 live contacts.
Early transmissions also had and extra output speed sensor (4-pin connector, 3 pins live) which was feeding the signal through a ballast to the Transmission Control Unit.
Signals provided by the transmission
2 RPM sensors (namely n2 and n3). They seem not to be measuring input / output speed directly. They rather measure internal transmission rotating components speed. They are both measuring on 60-teeth patters and they seem to be of hall-effect type sensors (the are internally wired with 3 wires). Sensor n2 provides its’ output to pin 3 whilst sensor n3 provides its’ output to pin 1. They are both grounded via pin 12 and are supplied with current via pin 7.
Oil temperature sensor (namely b1). It is a temperature dependent resistor connected to pins 4 (signal) and 12 (ground). It is connected in line with the starter lockout contact switch (see below). Temperature information is thus only available when the selector is not in ‘P’ or ‘N’. Sensor calibration data is available.
Starter Lockout Contact (namely s1). It is a switch which is connected in line with the temperature sensor. It is open (i.e. no current flows) when the selector lever is in ‘P’ or ‘N’ and closes in all other selector lever positions.
Output Speed Sensor (namely B49). Separate from the 13-pin connector. No further information available yet.
Actuators on the transmission
The transmission has 6 solenoid valves which control its’ hydraulic circuits.
Modulating pressure control solenoid valve (namely y1). Seems to be PWM controlled. It is connected to pin 6 (which is the common supply for all solenoids) and pin 2 (ground). It is controlled via pin 2.
Shift pressure control solenoid valve (namely y2). Seems to be PWM controlled. It is connected to pin 6 (supply) and pin 10 (ground). It is controlled via pin 10.
1-2 and 4-5 shift solenoid valve (namely y3). Seems to be on/off controlled. It is connected to pin 6 (supply) and pin 13 (ground). It is controlled via pin 13.
3-4 shift solenoid valve (namely y4). Seems to be on/off controlled. It is connected to pin 6 (supply) and pin 11 (ground). It is controlled via pin 11.
2-3 shift solenoid valve (namely y5). Seems to be on/off controlled. It is connected to pin 6 (supply) and pin 8 (ground). It is controlled via pin 8.
Torque converter lockup PWM solenoid valve (namely y6). It is PWM controlled. It is connected to pin 6 (supply) and pin 9 (ground). It is controlled via pin 9.
Selector Lever
Latest models are equipped with a touch-shift selector lever (P-R-N-D and ‘+’ & ‘-‘) with mechanical linkage for P-R-N-D and which provides signals via CAN bus for upshift/downshift.
Earlier models (like the first ML-Class) equipped with the 722.6 transmission were fitted with a voltage coded selector lever (P-R-N-D-4-3-2-1) with mechanical linkage for P-R-N-D and voltage output via a Gear Recognition Switch. No further information yet.
I am planning to do a logging/analysis of the actual electrical signals between the transmission and the transmission control unit in the next couple of weeks.
I will post the results here as soon as they are available.
From my point of view there are is a fundamental difference with the other transmissions currently supported by MegaShift. The difference lies in the presence of two pressure controlling solenoids instead of one.
I know that the basic design of the 722.6 family of transmissions has remained the same over the years. Of course lots of technical improvements have been introduced.
I presume that once MegaShift is configured to run the particular transmission, any other 722.6 transmission will be just a matter of tuning.
I would like to hear you comments and opinions on the subject.
Regards
Michael
Mercedes-Benz 722.6 (NAG1) Automatic Transmission
-
Bernard Fife
- Posts: 1696
- Joined: Fri Apr 04, 2008 1:28 pm
Re: Mercedes-Benz 722.6 (NAG1) Automatic Transmission
Michael,
It isn't possible to say much about the two pressure control solenoids without a lot more information.
It is very unlikely that the CAN shifter would be supported, as this would require a lot of 'inside info' about the processor and its memory layout used for the shifter (this info can be very difficult to impossible to get for most vehicles).
The rest of the requirements look possible with few or no code modification in a quick glance.
Lance.
It isn't possible to say much about the two pressure control solenoids without a lot more information.
It is very unlikely that the CAN shifter would be supported, as this would require a lot of 'inside info' about the processor and its memory layout used for the shifter (this info can be very difficult to impossible to get for most vehicles).
The rest of the requirements look possible with few or no code modification in a quick glance.
Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
Re: Mercedes-Benz 722.6 (NAG1) Automatic Transmission
Hello Lance,
Thanks for your reply.
The CAN (touch-shift) shifter cannot be used for other reasons also. It is part of the vehicle's security system and requires VIN specific coding and matching to the other control units of the vehicle.
Obviously it is rather impossible to utilise one of these shifters with MS.
Using the 'analog' shifter should be pretty much a straight forward job. Some versions also include a solenoid which acts as an inhibitor switch, preventing selection out of P or N without depressing the brake pedal.
I will get my hands on one of these shifters soon and have it analysed - it is available both as a complete shifter module (in various versions) and as individual parts from Mercedes-Benz.
Regarding the two pressure regulating solenoids I have some more information:
Shift pressure control solenoid valve (y2) controls the shift pressure. Shift pressure varies depending on engine/transmission load and gear change.
Shift pressure regulates the pressure in the activating shift elements during the shift phase and determines (together with the modulating pressure) the pressure reduction at the deactivating shift elements.
Shift pressure also initiates 2nd gear in emergency (limp-home) mode.
Shift pressure ranges between 0 to 15 bar (0-220 psi).
Modulating pressure control solenoid valve (y1) controls the modulating pressure. Modulating pressure varies depending on engine/transmission load.
Modulating pressure influences the magnitude of the working pressure and determines (together with the shift pressure) the pressure reduction at the deactivating shift elements.
Modulating pressure ranges between 0 to 8 bar (0-120 psi).
The working pressure (or Line Pressure or Operating Pressure) provides the pressure supply to the hydraulic control and the transmission shift elements. It is the highest hydraulic pressure in the entire hydraulic system. The working pressure is regulated at the working pressure regulating valve in relation to the load and gear. All other pressures required for the transmission control are derived from the working pressure.
Working Pressure ranges between 3,5 to 24 bar (50-350 psi).
Regarding the transmission input shaft (turbine) speed, the combination of the two RPM sensors (n2 and n3) can bu used to obtain it: Depending on whether n3 is 0 or not, n2 output needs to be multiplied by a factor 'c' in order to obtain the real input shaft speed: Input Shaft Speed = n2 * If ( n3=0;c;1) -> (If n3 = 0 then input shaft speed equals n2 X c, otherwise input shaft speed = n2).
'c' is a constant and should be around 0,60.
When I have more information I will make them available.
Once again thanks.
Regards
Michael
Thanks for your reply.
The CAN (touch-shift) shifter cannot be used for other reasons also. It is part of the vehicle's security system and requires VIN specific coding and matching to the other control units of the vehicle.
Obviously it is rather impossible to utilise one of these shifters with MS.
Using the 'analog' shifter should be pretty much a straight forward job. Some versions also include a solenoid which acts as an inhibitor switch, preventing selection out of P or N without depressing the brake pedal.
I will get my hands on one of these shifters soon and have it analysed - it is available both as a complete shifter module (in various versions) and as individual parts from Mercedes-Benz.
Regarding the two pressure regulating solenoids I have some more information:
Shift pressure control solenoid valve (y2) controls the shift pressure. Shift pressure varies depending on engine/transmission load and gear change.
Shift pressure regulates the pressure in the activating shift elements during the shift phase and determines (together with the modulating pressure) the pressure reduction at the deactivating shift elements.
Shift pressure also initiates 2nd gear in emergency (limp-home) mode.
Shift pressure ranges between 0 to 15 bar (0-220 psi).
Modulating pressure control solenoid valve (y1) controls the modulating pressure. Modulating pressure varies depending on engine/transmission load.
Modulating pressure influences the magnitude of the working pressure and determines (together with the shift pressure) the pressure reduction at the deactivating shift elements.
Modulating pressure ranges between 0 to 8 bar (0-120 psi).
The working pressure (or Line Pressure or Operating Pressure) provides the pressure supply to the hydraulic control and the transmission shift elements. It is the highest hydraulic pressure in the entire hydraulic system. The working pressure is regulated at the working pressure regulating valve in relation to the load and gear. All other pressures required for the transmission control are derived from the working pressure.
Working Pressure ranges between 3,5 to 24 bar (50-350 psi).
Regarding the transmission input shaft (turbine) speed, the combination of the two RPM sensors (n2 and n3) can bu used to obtain it: Depending on whether n3 is 0 or not, n2 output needs to be multiplied by a factor 'c' in order to obtain the real input shaft speed: Input Shaft Speed = n2 * If ( n3=0;c;1) -> (If n3 = 0 then input shaft speed equals n2 X c, otherwise input shaft speed = n2).
'c' is a constant and should be around 0,60.
When I have more information I will make them available.
Once again thanks.
Regards
Michael
Re: Mercedes-Benz 722.6 (NAG1) Automatic Transmission
Hello again,
I did some preliminary test measurements today on a 2008 E-Class (E200 Kompressor) which is fitted with the 722.695 (W5A330) transmission, which is similar to the one I described previously.
I used a Fluke 83 DMM (Digital MultiMeter) for the measurements, which is able to measure both frequency and duty cycle on PWM signals. I took measurements with the vehicle both stationary and whilst on the move.
I also used an osciloscope to have a better look on some of the signals, but only with the vehicle stationary (this time!). I am planning to use it with the vehicle moving too, soon.
Here is what I discovered:
The Modulating pressure control solenoid valve (y1) is PWM controlled with a frequency of 1000Hz and a voltage magnitude of 12 volts. The duty cycle was found to be in the range of 40% to 60% and varied according to load. The higher the load the lower the duty cycle. I did not test the full spectrum of loads so maybe the overall range may vary.
The Shift pressure control solenoid valve (y2) is PWM controlled with a frequency of 1000Hz and a voltage magnitude of 12 volts. The particular solenoid is ONLY ACTIVE DURING SHIFTS. I measured a duty cycle of about 45% for the duration of the shift and then activity stops. It seems that this solenoid initiates and finalizes the shift phase of all shifts. One other interesting finding is that the solenoid is also active when the selector is in P or N. Maybe this is related to the emergency limp-home mode functionality.
The 1-2 and 4-5 shift solenoid valve (y3), 3-4 shift solenoid valve (y4) and 2-3 shift solenoid valve (y5) might also be PWM controlled, but I haven't thoroughly tested this. The are only active during the respective shifts. I measured a voltage of about 4.5 Volts during shifts. I was not able to check the timing of the activation in relation to the shift pressure solenoid because I did not have an osciloscope on the move.
The following table is a preliminary overview of the shift logic:
Engaged Gear, Shift Solenoid Enabled, Resulting Gear
1 y3 2
2 y3 1
2 y5 3
3 y5 2
3 y4 4
4 y4 3
4 y3 5
5 y3 4
I will thoroughly verify the validity of the table and post my findings.
Torque converter lockup PWM solenoid valve (y6) is PWM controlled with a frequency of 100Hz and a voltage magnitude of 12 volts. No further data could be gathered due to traffic related constraints.
Conclusively, shift pressure solenoid and shift solenoids are only active during shifts. The transmission cannot skip gears during shifts (i.e. It cannot go from 2nd to 4th directly. It will go from 2nd to 3rd and then from 3rd to 4th).
Further tests and results will follow.
Regards
Michael
I did some preliminary test measurements today on a 2008 E-Class (E200 Kompressor) which is fitted with the 722.695 (W5A330) transmission, which is similar to the one I described previously.
I used a Fluke 83 DMM (Digital MultiMeter) for the measurements, which is able to measure both frequency and duty cycle on PWM signals. I took measurements with the vehicle both stationary and whilst on the move.
I also used an osciloscope to have a better look on some of the signals, but only with the vehicle stationary (this time!). I am planning to use it with the vehicle moving too, soon.
Here is what I discovered:
The Modulating pressure control solenoid valve (y1) is PWM controlled with a frequency of 1000Hz and a voltage magnitude of 12 volts. The duty cycle was found to be in the range of 40% to 60% and varied according to load. The higher the load the lower the duty cycle. I did not test the full spectrum of loads so maybe the overall range may vary.
The Shift pressure control solenoid valve (y2) is PWM controlled with a frequency of 1000Hz and a voltage magnitude of 12 volts. The particular solenoid is ONLY ACTIVE DURING SHIFTS. I measured a duty cycle of about 45% for the duration of the shift and then activity stops. It seems that this solenoid initiates and finalizes the shift phase of all shifts. One other interesting finding is that the solenoid is also active when the selector is in P or N. Maybe this is related to the emergency limp-home mode functionality.
The 1-2 and 4-5 shift solenoid valve (y3), 3-4 shift solenoid valve (y4) and 2-3 shift solenoid valve (y5) might also be PWM controlled, but I haven't thoroughly tested this. The are only active during the respective shifts. I measured a voltage of about 4.5 Volts during shifts. I was not able to check the timing of the activation in relation to the shift pressure solenoid because I did not have an osciloscope on the move.
The following table is a preliminary overview of the shift logic:
Engaged Gear, Shift Solenoid Enabled, Resulting Gear
1 y3 2
2 y3 1
2 y5 3
3 y5 2
3 y4 4
4 y4 3
4 y3 5
5 y3 4
I will thoroughly verify the validity of the table and post my findings.
Torque converter lockup PWM solenoid valve (y6) is PWM controlled with a frequency of 100Hz and a voltage magnitude of 12 volts. No further data could be gathered due to traffic related constraints.
Conclusively, shift pressure solenoid and shift solenoids are only active during shifts. The transmission cannot skip gears during shifts (i.e. It cannot go from 2nd to 4th directly. It will go from 2nd to 3rd and then from 3rd to 4th).
Further tests and results will follow.
Regards
Michael
Re: Mercedes-Benz 722.6 (NAG1) Automatic Transmission
Hi. Did you got tranny work on GPIO?
I have my self 722.6 (W5A580) tranny and think i go to GPIO
I have my self 722.6 (W5A580) tranny and think i go to GPIO
Re: Mercedes-Benz 722.6 (NAG1) Automatic Transmission
Hello Again,
It has been quite a long time since my last post but I haven't given up the project. I was waiting for my Labjack UE-9 Pro to be delivered in order to start logging and analysing.
My labjack (and quite a lot of accessories) arrived some weeks ago but I did not have the time to set it up and do the testing. It seems quite powerful though and offers a lot of functions to monitor PWM signals.
I only did some preliminary logging (to get used to the interface and labjack's logic) and found it to be very reliable and fast. It can stream data at a rate of more than 1000Hz per channel on more than 6 channels simultaneously. I just need to find the time to set it up properly and do the test drives for the logging. I will keep you informed.
Regards
Michael
It has been quite a long time since my last post but I haven't given up the project. I was waiting for my Labjack UE-9 Pro to be delivered in order to start logging and analysing.
My labjack (and quite a lot of accessories) arrived some weeks ago but I did not have the time to set it up and do the testing. It seems quite powerful though and offers a lot of functions to monitor PWM signals.
I only did some preliminary logging (to get used to the interface and labjack's logic) and found it to be very reliable and fast. It can stream data at a rate of more than 1000Hz per channel on more than 6 channels simultaneously. I just need to find the time to set it up properly and do the test drives for the logging. I will keep you informed.
Regards
Michael
Re: Mercedes-Benz 722.6 (NAG1) Automatic Transmission
Any updates on this build/test?
Re: Mercedes-Benz 722.6 (NAG1) Automatic Transmission
Hello to Cyprus,
while searching the web I found this article. I'm Robert from Germany and I'm driving a W460 280GE. It's a Rallye-hobby-vehicle. So far it used a 2.8 litre M110 engine with an eaton charger and automatic transmission.
The engine was controlled by an MS2 with coil on plugs. Now it is converted to an M104 3.6AMG with the 722.6 automatic transmission. Plan for 2013 is to get this thing running with a MS and shifting and then also do an eaton conversion.
How far did you get with your Megashift-Project? I got all the WIS-information availiable for the 722.6xx transmission. Is your transmission already running?
Hope to get a positive reply.
Regards
Robert
while searching the web I found this article. I'm Robert from Germany and I'm driving a W460 280GE. It's a Rallye-hobby-vehicle. So far it used a 2.8 litre M110 engine with an eaton charger and automatic transmission.
The engine was controlled by an MS2 with coil on plugs. Now it is converted to an M104 3.6AMG with the 722.6 automatic transmission. Plan for 2013 is to get this thing running with a MS and shifting and then also do an eaton conversion.
How far did you get with your Megashift-Project? I got all the WIS-information availiable for the 722.6xx transmission. Is your transmission already running?
Hope to get a positive reply.
Regards
Robert
Megashift and the NAG1 722.6xx Mercedes Transmission?
Hello,
I'm Robert from Germany and I'm driving a W460 280GE. So far it was powered by a 2.8 litre M110 engine with an eaton charger and a full hydraulik automatic transmission.
The engine was controlled by an MS2 with coil on plugs. There are some pictures in the german Megasquirt-Forum http://www.megasquirt.de/msforum/viewto ... f=2&t=2067
Now we do an engine swap to a M104 3.6AMG. The engine is out of a W202 with the 722.6 automatic transmission. Plan for 2013 is to get this thing running, again with a MS. If it runs, there is already a new eaton waiting in the garage...
Our challange is to get the automatic transmission working. The MB-gearbox-ecu needs signals from the engine-, ABS- and antithief-ecu.
The idea was to use Megashift. I already did some research on the solenoids, pressures, PWM signals und shifting cycles. But its hard to find anything about Megashift and the NAG1 / 722.6 gearbox.
Is there an working 722.6 thats controlled by Megashift?
Hope to get a positive reply.
Regards
Robert
PS: The Mercedes NAG1 (neues Automatikgetriebe 1) was used in innumerable MB, Porsche and Chrysler models.
I'm Robert from Germany and I'm driving a W460 280GE. So far it was powered by a 2.8 litre M110 engine with an eaton charger and a full hydraulik automatic transmission.
The engine was controlled by an MS2 with coil on plugs. There are some pictures in the german Megasquirt-Forum http://www.megasquirt.de/msforum/viewto ... f=2&t=2067
Now we do an engine swap to a M104 3.6AMG. The engine is out of a W202 with the 722.6 automatic transmission. Plan for 2013 is to get this thing running, again with a MS. If it runs, there is already a new eaton waiting in the garage...
Our challange is to get the automatic transmission working. The MB-gearbox-ecu needs signals from the engine-, ABS- and antithief-ecu.
The idea was to use Megashift. I already did some research on the solenoids, pressures, PWM signals und shifting cycles. But its hard to find anything about Megashift and the NAG1 / 722.6 gearbox.
Is there an working 722.6 thats controlled by Megashift?
Hope to get a positive reply.
Regards
Robert
PS: The Mercedes NAG1 (neues Automatikgetriebe 1) was used in innumerable MB, Porsche and Chrysler models.
Re: Mercedes-Benz 722.6 (NAG1) Automatic Transmission
Here have been quiet in this topic... I´m planing to use 722.6 box with ford v8 engine and have been tried to learn how this gearbox works.
Is it possible to make with reasonable amount of work and time solenoid outputs to give just one pulse which time can be adjusted? In Solenoid PWM Setup You can adjust solenoid work on/off and give time for both functions. Is it possible to give just pulse on time (like 0.128->1000ms) and solenoid output is then off? I think that will solve problems to control 722.6 gearbox.
Is it possible to make with reasonable amount of work and time solenoid outputs to give just one pulse which time can be adjusted? In Solenoid PWM Setup You can adjust solenoid work on/off and give time for both functions. Is it possible to give just pulse on time (like 0.128->1000ms) and solenoid output is then off? I think that will solve problems to control 722.6 gearbox.