[hupchye]

Originally Posted by unrulyteach

Ista

Hi unrulyteach, earlier I obtained my car electrical diagram, maintenance guideline from newTIS.info.

Ista ? Which website is it ?

[hupchye]

Originally Posted by hupchye

Hi unrulyteach, earlier I obtained my car electrical diagram, maintenance guideline from newTIS.info.

Ista ? Which website is it ?

Oh ! Got it.

https://aos.bmwgroup.com/

[hupchye]

Originally Posted by hupchye

Ya, I did some precaution before flashing DME ie: backup the ECU program and clone a spare ECU using Ktag.

After successfully flash and update the ecu software, problem still the same but came out 2x fault codes :

62D4 LDM: Engine management: interface
3179 Message (request, wheel torque, drivetrain, 0xBF) incorrect, receiver
DME, transmitter LDM

I am going to buy a 2nd unit LDM module to swap. Hopefully is a faulty LDM problem. Otherwise, I am totally lost..

Update ! Today fault codes 62D4 & 3179 problem have been resolved. It was due to PT Can Bus tapping problem. I think it is technically important for 4cyl BMW ACC retrofit ie:

4) PT Can Bus network require 120 ohm resistor end to end to form a 60 ohm network (Pic.1). The PT Can Bus termination resistor was in the module for older BMW model ie: EKPS & DSC. Unlike 6cyl BMW PT Can Bus layout (Pic.1), they have EKPS, Active Steering, Adaptive Headlight etc in the network. For ACC & LDM to tap out PT Can Bus from DSC may not have problem. But 4cyl BMW has lesser module in PT Can Bus network (Pic.3). Just tapping out from DSC may have PT Can Bus errors due to network end to end length. I modified to Pic.4 ie: cut thru PT Can Bus at DSC therefore DSC still the end node.

Unfortunately after fault codes cleared, my car ACC cruise control still cannot maintain speed.

[Nickco43]

Originally Posted by hupchye

Update ! Today fault codes 62D4 & 3179 problem have been resolved. It was due to PT Can Bus tapping problem. I think it is technically important for 4cyl BMW ACC retrofit ie:

4) PT Can Bus network require 120 ohm resistor end to end to form a 60 ohm network (Pic.1). The PT Can Bus termination resistor was in the module for older BMW model ie: EKPS & DSC. Unlike 6cyl BMW PT Can Bus layout (Pic.1), they have EKPS, Active Steering, Adaptive Headlight etc in the network. For ACC & LDM to tap out PT Can Bus from DSC may not have problem. But 4cyl BMW has lesser module in PT Can Bus network (Pic.3). Just tapping out from DSC may have PT Can Bus errors due to network end to end length. I modified to Pic.4 ie: cut thru PT Can Bus at DSC therefore DSC still the end node.

Unfortunately after fault codes cleared, my car ACC cruise control still cannot maintain speed.

Its strange how there are so many differences between 4 and 6 cylinder E90s for ACC.

[shannon1]

Wow. Good work in figuring that out.

[hupchye]

Unfortunately, my ACC still cannot hold speed

Hopefully is due to I DIY the rear wheel speed sensor signals. Bcos kombi cluster taking reading from rear left speed sensor, cruise control taking from rear right.

[Mr.Retrofit]

Originally Posted by hupchye

Unfortunately, my ACC still cannot hold speed

Hopefully is due to I DIY the rear wheel speed sensor signals. Bcos kombi cluster taking reading from rear left speed sensor, cruise control taking from rear right.

Time to change the wheel bearing and sensor??

[hupchye]

Originally Posted by Mr.Retrofit

Time to change the wheel bearing and sensor??

I am not convinced yet.
Normally DME controls speed thru throttle actuator valve in Cruise control mode. I have monitored using INPA after ACC cruise speed set, throttle actuator valve no activity at all (0.7v). I afraid LDM is not compatible to 4cyl DME (MV946, MV1746). 6cyl has DME MSD70/80, MSV70/80.
Let me dig out more...

[Mr.Retrofit]

Originally Posted by hupchye

I am not convinced yet.
Normally DME controls speed thru throttle actuator valve in Cruise control mode. I have monitored using INPA after ACC cruise speed set, throttle actuator valve no activity at all (0.7v). I afraid LDM is not compatible to 4cyl DME (MV946, MV1746). 6cyl has DME MSD70/80, MSV70/80.
Let me dig out more...

Have you something that can analyse the CAN signals? Perhaps you might see the packets from the LDM requesting the DME to increase engine speed. At least you would know that it is working correctly then?
After that, it would be a matter of figuring out what the CAN packets from the 4cyl cruise are and comparing them, if the packets are different then perhaps a CAN injector circuit would need to be built.

I wish I could be of more use but I am still in the 'hunting' stage of my project BUT my CAN analyser should be here in a week...

[hupchye]

Originally Posted by Mr.Retrofit

Have you something that can analyse the CAN signals? Perhaps you might see the packets from the LDM requesting the DME to increase engine speed. At least you would know that it is working correctly then?
After that, it would be a matter of figuring out what the CAN packets from the 4cyl cruise are and comparing them, if the packets are different then perhaps a CAN injector circuit would need to be built.

I wish I could be of more use but I am still in the 'hunting' stage of my project BUT my CAN analyser should be here in a week...

Good idea ! I will do that.

[hupchye]

Originally Posted by Mr.Retrofit

Have you something that can analyse the CAN signals? Perhaps you might see the packets from the LDM requesting the DME to increase engine speed. At least you would know that it is working correctly then?
After that, it would be a matter of figuring out what the CAN packets from the 4cyl cruise are and comparing them, if the packets are different then perhaps a CAN injector circuit would need to be built.

I wish I could be of more use but I am still in the 'hunting' stage of my project BUT my CAN analyser should be here in a week...

Hi mate, since I already retrofit ACC to my car halfway, there is no way for me to get the CanBus packets from the 4cyl original DSC to DME MV1746 for basic cruise control.
Let's work together to solve this last piece of the puzzle for 4cyl ACC retrofit ie: I get the CanBus packets from LDM to DME & you get the CanBus packets from original DSC to DME ?

[Mr.Retrofit]

Originally Posted by hupchye

Hi mate, since I already retrofit ACC to my car halfway, there is no way for me to get the CanBus packets from the 4cyl original DSC to DME MV1746 for basic cruise control.
Let's work together to solve this last piece of the puzzle for 4cyl ACC retrofit ie: I get the CanBus packets from LDM to DME & you get the CanBus packets from original DSC to DME ?

Yes, of course!
I am hoping to have my CAN analyser here sometime next week. I've used packet sniffers before so have some experience but I plan on using SavvyCAN so there will be a bit of a learning curve with that but hopefully, it won't all take too long to figure out.

[hupchye]

Originally Posted by Mr.Retrofit

Yes, of course!
I am hoping to have my CAN analyser here sometime next week. I've used packet sniffers before so have some experience but I plan on using SavvyCAN so there will be a bit of a learning curve with that but hopefully, it won't all take too long to figure out.

Hi, since you use SavvyCAN, attached E9x DBC file from github may help you speed up in cruise control msg ID searching/filtering.

[hupchye]

Originally Posted by Mr.Retrofit

Yes, of course!
I am hoping to have my CAN analyser here sometime next week. I've used packet sniffers before so have some experience but I plan on using SavvyCAN so there will be a bit of a learning curve with that but hopefully, it won't all take too long to figure out.

From the DBC file interpreted PT CAN Bus Msg ID, 4x related to cruise control :

Msg ID Msg Name
0x0AA AccPedal [ACC Cruise Control $541]
0x194 CruiseControl [Command/Msg from SZL]
0x200 CruiseControlStatus [Cruise Control $540]
0x193 DynamicCruiseControlStatus [Cruise Control with Brake $544]

If I understand correctly, 4cyl BMW DME understand Msg ID 0x200 and may not responds to Msg ID 0x0AA & 0x194.
Let me try out and see...

[hupchye]

Originally Posted by Mr.Retrofit

Yes, of course!
I am hoping to have my CAN analyser here sometime next week. I've used packet sniffers before so have some experience but I plan on using SavvyCAN so there will be a bit of a learning curve with that but hopefully, it won't all take too long to figure out.

Hi, what CAN analyser hardware interface you will be using ?

[hupchye]

Originally Posted by Mr.Retrofit

Have you something that can analyse the CAN signals? Perhaps you might see the packets from the LDM requesting the DME to increase engine speed. At least you would know that it is working correctly then?
After that, it would be a matter of figuring out what the CAN packets from the 4cyl cruise are and comparing them, if the packets are different then perhaps a CAN injector circuit would need to be built.

I wish I could be of more use but I am still in the 'hunting' stage of my project BUT my CAN analyser should be here in a week...

I foresee if 4cyl DME not compatible to accept CAN packets form LDM for 0x0AA ACCPedal and 0x193 DynamicCruiseControlStatus, like you said, a CAN injector circuit (CAN Bus Bridge/ Translator) would need to be built between current PT-CAN Bus and LDM.
Since PT-CAN Bus original protocol/ Msg ID pattern from LDM might need to be altered, I am thinking ... whether to program the CAN Bus Bridge/ Translator to accommodate similar to Stop & Go function.

Therefore, today I tested with LDM module with custom coding :

V_ABSCHALT_KMH (CRUISE CONTROL SWITCH-OFF SPEED IN KM/H) 0 km/h
V_ABSCHALT_MPH (CRUISE CONTROL SWITCH-OFF SPEED IN M/H) 0 mph

Result : When ACC ON at 50km/h and distance set to closest (1 bar), object/ car detected in front, Orange color car symbol appeared on Cluster, DSC brakes On, car slow down, then followed by Red color car symbol, car speed at approx 15km/h, LDM fault code 62DA - (LDM: Control module: safety cutout, drive) cuts in and disable the DSC brakes and ACC.

It looks to me there is a possibility of Stop & Go if reprogram the LDM CAN Bus Msg. And of course is for experimental and more testing require.

[Mr.Retrofit]

Originally Posted by hupchye

Hi, what CAN analyser hardware interface you will be using ?

Macchina M2, hopefully here early next week.

[hupchye]

Originally Posted by Mr.Retrofit

Macchina M2, hopefully here early next week.

[hupchye]

Originally Posted by hupchye

From the DBC file interpreted PT CAN Bus Msg ID, 4x related to cruise control :

Msg ID Msg Name
0x0AA AccPedal [ACC Cruise Control $541]
0x194 CruiseControl [Command/Msg from SZL]
0x200 CruiseControlStatus [Cruise Control $540]
0x193 DynamicCruiseControlStatus [Cruise Control with Brake $544]

If I understand correctly, 4cyl BMW DME understand Msg ID 0x200 and may not responds to Msg ID 0x0AA & 0x194.
Let me try out and see...

Hi, attached CAN packets was sniffed on my car's PT-CAN bus using Python program and cheap ELM327 OBD2 adapter. It is confirmed that ACC use Msg ID 0x0AA and 0x194 to control.

[hupchye]

Using setting

CAN bus: 11-bit, 500.00 kb/s (ISO 15765-4)

[hupchye]

Seems like my 4cyl DME MEV1746 is not response to ACC Msg ID 0x0AA (9 signals) whereby DCC Msg ID 0x193 have 4 signals and CC Msg ID 0x200 only have 3 signals. Next I will:

1) coding to VO $544, test drive and sniff on PT-CAN Bus (Msg ID 0x193)
then
2) coding to VO $540, test drive and sniff on PT-CAN Bus (Msg ID 0x200)
- 6cyl DSC may not work on VO$540, I may need to swap back the 4cyl DSC

before making the final conclusion.

[mtman]

Originally Posted by hupchye

I did quite a survey in sourcing 6cyl DSC.
I found all sellers in ebay advertise with the p/n of the "control module" & the "pump" bcos thats what they can see from the item labels, while in BMW parts catalog is the p/n for the whole DSC pump unit.
For example: I bought the 6cyl DSC from ebay with p/n 6775388, 6775389. And p/n in BMW parts catalog is 34516775396. They are no relation at all.
Eventually, I sourced with few conditions :
1) with keyword "E90 DSC Hydro Braking Pump"
2) part dismantled from 323i, 325i, 325d, 330i, 330d, 335i, 335d with engine type N52, N52N, M57N2, N54
3) countercheck (if possible) this DSC used wheel speed sensor 34526870075, 34526870076 & 34526870077 in BMW parts catalog
The older the part, the least expensive they are.
Hope this helps.

I went trough same painfull research and realise that:
To simplify... 6zyl dsc have a notch in the ecu edge (like two rectangulars), while 4zyl dsc have straight rectangular (like 1 rectengular) ecu.

Hope that helps in future serching.
MT