Quote:
Originally Posted by hupchye
Update !! Bad news !!
Attached PT-Can log sniffed during ACC On and playback in SavvyCan.
It is confirmed that my 4Cyl BMW E92 DME MEV1746 no response to PT-Can Msg ID.0x0AA AccPedal ie: ThrottlelPressed & AcceleratorPedalPressed signal commands. Therefore cruise speed not hold.
My side conclusion for my 4cyl BMW E9x ACC Retrofit which come so far :
1) replace with 6cyl DSC hydro braking pump to get rid of Wheel Torque error
2) for Diesel engine - replace wheel speed sensor 34526762465 (front) & 34526764610 with 34526870075 (front) & 34526870077 (rear) only
3) for Petrol engine - replace wheel speed sensor 34526762465 (front) & 34526762466 (rear) with 34526870075 (front)& 34526870076 (rear) + replace rear wheel angular bearing 33416762317 (42X75X37) with magnetic encoder type bearing (may not need to change complete hub/driveshaft assembly as 34526870076 (rear) sensor still able to sense thru the gap between reluctor ring and wheel hub if magnetic encoder type bearing installed)
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.
5) 4cyl BMW DME MEV1746 not compatible with ACC commands - Dead End from OEM design 
May be others will have different finding/solution during their trial.
I will still proceed to integrate Can-Bus bridge/repeater to LDM module. See whether can do some magic and make ACC works in my E92 ... |
Correction and additional info.
Today I disconnected the LDM module and sniff on the PT-Can to know what Can Msg. ID list sent out from it. Surprisingly Msg. ID 0x0AA is still there. And the list of Can Msg. ID sent out from LDM module are :
1) 0x0BF RequestedWheelTorqueDriveTrainActiveCruiseControl
2) 0x0D5 ?
3) 0X150 ?
4) 0x153 ?
5) 0x159 ?
6) 0x15C ?
7) 0x193 DynamicCruiseControlStatus
That means my DME MEV1746 is not response to Msg. ID 0x193 not Msg. ID 0x0AA yet. And I believe Msg. ID 0x0AA is from DSC.
If I translate/convert Msg. ID 0x193 to Msg. ID 0x200 which accepted by 4cyl BMW for basic cruise control, then only we can see whether Msg. ID 0x0AA controls works or not .... Let's find out !