Anyone found a good canbus resource for Subaru?

[Gripless]

While there are some canbus messages ID decoded I haven’t found a great one.

 

Looking for:

TPMS tire pressure 

Intake pressure

DCCD g force sensors etc

Currently trying to build a TPMS canbus to bluetooth aftermarket sensors. Have managed to write the code to detect and read sensors now I understand how they work. Going to try and make the code user friendly so anyone can buy and pair sensors and connect them to car. Just a little LCD on a hide away box that triggers the OEM dash light or the dash top screen.

[Andy_Mac]

Cool idea. Would like some sensors again but definitely need to be proper integrated ones rather than big lumps on the stems. 
 

Another one that is a heap more work but very needed is decoding DCCD stuff for the dash so an aftermarket one can display it. Seems a real pain for anyone wanting to go full digital with no way to show current mode/settings. 

[Gripless]

3 hours ago, Andy_Mac said:

Cool idea. Would like some sensors again but definitely need to be proper integrated ones rather than big lumps on the stems. 
 

Another one that is a heap more work but very needed is decoding DCCD stuff for the dash so an aftermarket one can display it. Seems a real pain for anyone wanting to go full digital with no way to show current mode/settings. 

The sensors that replace the valve stem are the same chip and protocol  so you can just choose those. I got external ones as don’t want to pull tires off until I need to.

 

What do you want for DCCD, just a display of auto/manual and lockup amount like the factory dash? A small board could read the messages and then trigger a 0/5v for auto manual, and digital variable resistor could be set for the lockup. That way the dash can read the resistor like a key pad. That would only need a digital and analog pin on the dash. 

Once I get to work on the canbus side I can check that as it seems easy to decode. Just toggle the switches and look for new canbus message ID’s

[Gripless]

@Andy_Mac 

Looking at 6MT manual DCCD has only 2 data points.

 

From manual…

DCCD mode 

0 manual or 1 auto

1 auto -

2 auto (defaults back to this when set to manual mode)

3 auto +

 

 

DCCD torque distribution 

0 when in auto mode

1 free

2

3

4

5

6 lock

 

On another page it states in error state the dash alternates from displaying 1 to 6 every second eg 1Hz but it doesn’t state if that’s sent from the DCCD controller as messages with 1 and 6 or it just sends an single error message and the dash then blinks that sequence. Only way to tell would be make DCCD have and error and then look at the messages. Canbus can have 8 bytes in a message the this uses only 2 so it can have error or operational state in the other 6 bytes.

 

 

I found someone had already decoded it and posted publicly so if your dash can do canbus you can configure it with the below….

 

ID 0x430

BYTE 1 is Differential Control
Bit 3 = 1 “Auto” , 0 “Manual”
Bit 0/1 = 11 is “+” , 10 is “-” , 01 “no change” , 01 also in Manual /automatic mode

 

BYTE 2 is Differential Control level
Bit0,1,2 

000 – 1 level
001 – 2 level
010 – 3 level
011 – 4 level
100 – 5 level
101 – 6 level
When “AUTO” select Diff control level is always 000

Looking at manual vs decoded there is a difference in lock and free level. Manual has 0-6 and the decoded has 0-5 which could just be a typo in the post.

 

 

[Andy_Mac]

Interesting. Had been talking to Niran and reading up on a few others having the same dilemma and they had all basically said you'd have to pay to have it sorted which could be big bucks to get sorted. 

[Gripless]

If you wanted a small LCD the mimics the factory dash that would be NZD$10- 20 in parts.

 

ESP32 board with tiny LCD screen. ESP32 have built in canbus controller.

https://www.aliexpress.com/item/1005007342383107.html

$7

 

Canbus transceiver. Does the actual canbus voltages and signals?

https://www.aliexpress.com/item/1005006832397047.html

$3

note: this is a 5v part so needs a 4k7 ohm resistor between the RX on canbus board and the esp32 which needs 3.3v max

 

5v voltage regulator like 7805 series, nothing fancy.

$0.5

 

Some wire to canbus and power etc.

free any old network cable works fine for canbus

 

Same hardware ESP32 can also connect to any aftermarket dash with a digital PWM input simultaneously.

The code on ESP32 could just duty cycle state of the diff. something like…

percent duty on the input

0 auto

10 auto -

20 auto +

30 manual level 1

40 manual level 2

60 manual level 3

70 manual level 4

80 manual level 5

90  manual level 6

100 error

in dash set the labels to show based on duty eg 0-5% duty show auto, 6-15 auto- etc

Or… if you have aftermarket ecu and dash already it’s FREE.
 

Add a math or table function/block in the ecu that takes the OEM canbus, which it’s connected to already to or you couldn’t press start or see si-drive state etc.

Then have that displayed on the dash.
 

Emtron has a canbus gauge that seems to have an app to make custom screens so that could be an option. Make 4 little icon for manual auto - + etc and have those shown based on ecu messages. Then can math the 1-6 into front rear bias based on the DCCD year which Subaru publish. Eg 50-50 front to 35-65 or just have the 1-6 bars like OEM dash.

 

Emtron call them calculated channels, for software use only eg  logger and dash.

https://help.emtronaustralia.com.au/emtune/Newtopic254.html

Edited February 8 by Gripless
Added Emtron link

[Gripless]

Posting for completeness of original 

Bosch sensor

 

0x80 = 128 decimal
0x70 = 112 decimal

BO_ 128 DRS_TX_ID2: 8 DRS_MM3x
SG_ AX1 : 32|16@1+ (0.00012742,-4.1768) [-4.1768|4.1765] “g” ABS
SG_ YawAcc : 0|16@1+ (0.125,-4096) [-4096|4095] “°/s²” ABS

BO_ 112 DRS_TX_ID1: 8 DRS_MM3x
SG_ AY1 : 32|16@1+ (0.00012742,-4.1768) [-4.1768|4.1765] “g” ABS
SG_ Yaw : 0|16@1+ (0.005,-163.84) [-163.84|163.83] “°/s” ABS

 

 

 

 

ID 0x70 BYTE 0 + BYTE 1 (16 bits) is yaw rate : (RAW * 0.005) -163.84) = YAW °/s [range -163.84|163.83]

ID 0x70 BYTE 4 + BYTE 5 (16 bits) is Y Acceler : (RAW * 0.00012742) –4.1768) = Y ACC “g” [range -4.1768|4.1765]

 

ID 0x70 BYTE 0 + BYTE 1 (16 bits) is yaw Accel : (RAW * 0.125) -4096) = YAW ACC °/s2 [range -4096|4095]
ID 0x70 BYTE 4 + BYTE 5 (16 bits) is Y Acceler : (RAW * 0.00012742) –4.1768) = Y ACC “g” [range -4.1768|4.1765]

[Joker]

keep 'em coming, kids in 30 years will find this & think you're a ledgend!

 

[Gripless]

Yeah that stuff was via archive.org since it was no longer on the original sites.

 

Next note 2007-2014 GR GD have a wire to the TPMS lamp, not via canbus like the 2016+ cars.

The TPMS can send canbus messages as it is in the unit that does keyless entry.

It’s in the hatch area on left. Only one panel around the rear quarter window needs to come out to undo the one bolt holding it in.

To interface with dash lamp any aftermart unit will need make use of the wire to dash cluster not canbus.

 

Seems DTC codes may be blinked out for all modules is via the dash.

within 10 seconds 

acc on

Headlights on

trip button 3 times

headlights off

trip button 3 times

page 2796 service manual has table of what the results are.

 

 

 

 

[Gripless]

Assembled and coding a canbus DCCD message emulator.

It can send random or preset messages over canbus.

 

Working on the graphic interface for the receiver which just displays the current state.

 

once that works I’ll connect it to the car diagnostics port and live test it.