The purpose of this page is to document as much data channels on the CAN bus as possible. If your goal is to set up data logging in RaceChrono, there is a better alternative: https://github.com/timurrrr/RaceChronoDiyBleDevice/blob/master/can_db/ft86_gen2.md
Special thanks to Ken Houseal for his early legwork on finding and documenting how to connect to the CAN bus, and finding some of these data mappings!
The ODB-II in the driver's footwell no longer exposes the CAN bus data except for OBD-II requests. If you want to log data with high refresh rates, you need to use an alternative connection. There are multiple options with different pros and cons. Below are the recommended ones:
Not available on US market Subaru BRZs. (Subaru, get your act together?)
GR86s and EU market BRZs have an unused connector hidden behind the glovebox, near the cabin air filter and the 12V socket:
You can carefully peel off the tape that keeps it out of the way. It's hard but doable, take your time!
You can buy a DCM/OBD adapter from Hachi Electronics.
Alternatively, you can make your own harness.
You can use the two middle pins of a
Toyota radio harness
to connect to the CAN bus through that connector.
Here are the pins that you need to use:
The green wire on the photo is CAN H, the white wire is CAN L.
This is only recommended for US BRZ owners, as it lacks some data.
A common place to get access to the CAN bus is the ASC (a.k.a. "fake engine noise") female connector. It is located inside the dash slightly to the right of the glovebox, and is accessible by pulling off the panel on the right side of the dash. The photo below shows the normal location of the connector with an arrow, and you can see the disconnected connector dangling in the bottom right of the photo:
You can buy an off-the-shelf harness that taps into the ASC connector and provides access to the CAN bus in an OBD-II form factor:
- https://hachielectronics.com/products/2022-gr86-brz-asc-can-adapter
- https://ansixauto.com/2022-brz-gt86-can-adapter (has an option to pass through the ASC connections)
Alternatively, you can make your own connector. You can then buy a male connector by TE Connectivity, part number 1376106-1. You will also need to buy male pins, part number 1376109-1.
If you're ok with not having the ASC, you need to get at least one connector and two pins. It might be useful to get some extra in case you fail to crimp the pins, or something like that.
If you want to keep ASC working, you can also buy a female connector and female pins, and make a "T" bridge. The part numbers and wiring schematics are out of scope of this documentation.
Here's how you should wire the male connector:
The blue wire on this photo is CAN H, the white wire is CAN L.
The full pinout of the ASC connector is here (with colors matching OEM wire colors):
Below are the examples of some high-frequency CAN IDs, along with some of the data channels that have already been decoded.
Note that the "equation" column in the decoding tables uses the RaceChrono equation format.
For example, if the data is
0x 12 34 56 78 90 AB CD EF
where bytes are named
-- (A)(B)(C)(D)(E)(F)(G)(H),
then here is how different equations are calculated:
| Equation | Value (hex) | Value (dec) |
|---|---|---|
A |
0x12 |
18 |
B |
0x34 |
52 |
F |
0xAB |
171 |
F * 0.1 |
N/A | 17.1 |
bytesToIntLe(raw, 0, 2) |
0x3412 |
13330 |
bytesToIntLe(raw, 3, 2) |
0x9078 |
-28552 |
bitsToIntLe(raw, 4, 12) |
0x341 |
833 |
You should be able to figure out the format for these equation for other data logging systems.
Update frequency: 100 times per second.
Example values:
0x 5D 0B C9 82 00 00 00 C7 (parked)
0x 10 0D FA 06 00 00 00 C3 (moving slowly)
| Channel name | Equation | Notes |
|---|---|---|
| Engine RPM | bitsToUIntLe(raw, 16, 14) |
|
| Accelerator position | E / 2.55 |
|
| Accelerator position | F / 2.55 |
Same value as E, until you press and hold both accelerator and brake, then 0. |
| Accelerator position | G / 2.55 |
Same as F. |
| ??? | H & 0xC0 |
0xC0 when off the accelerator pedal, 0x00 otherwise. |
Update frequency: 100 times per second.
Example values:
0x C9 43 96 A6 7B 27 65 02 (parked)
0x 94 4E 44 A7 78 27 7B 00 (moving slowly)
| Channel name | Equation | Notes |
|---|---|---|
| A/C fan clutch | H & 0x2 |
2 is engaged, 0 is disengaged |
Update frequency: 50 times per second.
Example values:
0x 7E 0F 00 07 00 4F 00 00 (parked)
0x 8C 02 00 21 00 50 00 00 (moving slowly)
Update frequency: 50 times per second.
Example values:
0x 28 0C DD 06 00 00 00 00 (parked)
0x 90 0D 13 FA 3F 00 00 00 (moving slowly)
| Channel name | Equation | Notes |
|---|---|---|
| Steering angle | bytesToIntLe(raw, 2, 2) * -0.1 |
Positive value = turning left. You can add a - if you prefer it the other way around. |
| Yaw rate | bytesToIntLe(raw, 4, 2) * -0.2725 |
Calibrated against the gyroscope in RaceBox Mini. Gen1 used 0.286478897 instead. |
Update frequency: 50 times per second.
Example values:
0x 72 5A 00 E0 08 00 DA 1C (parked)
0x 62 5B FC E0 08 00 CD 1C (moving slowly)
| Channel name | Equation | Notes |
|---|---|---|
| Speed | bitsToUIntLe(raw, 16, 13) * 0.015694 |
You may want to check the multiplier against an external GPS device, especially if running larger/smaller diameter tires |
| Brake lights switch | (E & 0x4) |
4 is on, 0 is off |
| Brake pressure | F * 128 |
Coefficient taken from 1st gen cars, but might need to be verified. |
When using RaceChrono, you might also consider the following interpretation of the F byte:
| Channel name | Equation | Notes |
|---|---|---|
| Brake position (%) | min(F / 0.7, 100) |
The 0.7 divider seems to be a good value to get 100% at pressure slightly higher than those you're likely to use on the track for cars with no aero. You can use 0.8 or 0.9 if you see 100% too often. |
This channel is not available on the B_CAN which connects to the ASC unit.
Update frequency: 50 times per second.
Example values:
0x 4A 0F 00 00 00 00 00 00 (parked)
0x 41 06 00 00 00 00 00 00 (parked)
0x 56 CF 0D 7C C1 35 C8 05 (moving at ~6 mph according to the speedometer, turning right)
0x FE 75 72 50 0E CC 79 39 (driving on a highway with 65 mph on the speedometer, straight line)
| Channel name | Equation | Notes |
|---|---|---|
| ??? | bitsToUIntLe(raw, 0, 12) | Constantly changing even when parked, perhaps some counter? |
| Wheel speed FL | bitsToUIntLe(raw, 12, 13) * 0.015694 |
Use same multiplier as for speed in 0x139 |
| Wheel speed FR | bitsToUIntLe(raw, 25, 13) * 0.015694 |
Use same multiplier as for speed in 0x139 |
| Wheel speed RL | bitsToUIntLe(raw, 38, 13) * 0.015694 |
Use same multiplier as for speed in 0x139 |
| Wheel speed RR | bitsToUIntLe(raw, 51, 13) * 0.015694 |
Use same multiplier as for speed in 0x139 |
Update frequency: 50 times per second.
Example values:
0x 47 0F 00 00 FF FF FF FF (parked)
0x 37 02 00 00 FF FF FE FD (moving slowly)
| Channel name | Equation | Notes |
|---|---|---|
| Lateral acceleration | bytesToIntLe(raw, 6, 1) * 0.2 |
|
| Longitudinal acceleration | bytesToIntLe(raw, 7, 1) * -0.1 |
|
| Combined acceleration | sqrt(pow2(bytesToIntLe(raw, 6, 1) * 0.2) + pow2(bytesToIntLe(raw, 7, 1) * 0.1)) |
Update frequency: 50 times per second.
Example values:
0x D4 0F 0E 38 02 00 40 00 (parked)
0x 12 0E 00 0B 0E 42 6C 00 (moving slowly)
This channel is not available on the DCM port.
Update frequency: 50 times per second.
Example values:
0x 51 0D 00 00 00 00 00 00 (parked)
0x 5C 07 00 10 01 00 00 00 (moving slowly)
| Channel name | Equation | Notes |
|---|---|---|
| Speed | bitsToUIntLe(raw, 24, 14) * 0.015694 |
You may want to check the multiplier against an external GPS device, especially if running larger/smaller diameter tires |
Update frequency: 50 times per second.
Example values:
0x 7C 1B CE 42 09 01 00 00 (parked)
0x 19 11 68 48 11 00 00 00 (moving slowly)
Update frequency: 20 times per second.
| Channel name | Equation | Notes |
|---|---|---|
| Clutch position (%) | (F & 0x80) / 1.28 |
100 is "clutch pedal depressed", 0 is "clutch pedal released" |
| Gear | bitsToUIntLe(raw, 35, 3) |
0 for N, 1—6 for gears 1–6 |
Update frequency: 33.3 times per second.
Example values:
0x 3A 06 40 00 20 00 00 00 (parked)
0x 3E 02 48 00 20 00 00 00 (moving slowly)
Update frequency: 10 times per second.
| Channel name | Equation | Notes |
|---|---|---|
| Engine oil temperature | D - 40 |
|
| Coolant temperature | E - 40 |
Update frequency: 10 times per second.
| Channel name | Equation | Notes |
|---|---|---|
| Air Temperature | E / 2 - 40 |
Update frequency: 10 times per second.
| Channel name | Equation | Notes |
|---|---|---|
| Fuel level (%) | 100 - (bitsToUIntLe(raw, 32, 10) / 10.23) |
Unfiltered/noisy. The equation is work in prorgess. |
Update frequency: 1 per second.
Example values (from a US car):
0x 00 00 04 FE FE FE FE FE (when pressures aren't displayed shortly after turning ignition on)
0x 00 00 04 48 42 46 44 FE (tire pressures in psi: 36 FL, 33 FR, 35 RL, 34 RR)
0x 00 00 24 4E 50 39 4E FE (tire pressures in psi: 39 FL, 40 FR, 28 RL, 39 RR; RL highlighted yellow, TPMS light on)
0x 00 00 24 37 35 48 46 FE (tire pressures in psi: 27 FL, 26 FR, 36 RL, 35 RR; FL and FR highlighted yellow, TPMS light on)
| Channel name | Equation | Notes |
|---|---|---|
| Tire pressure FL | lowPass(D >> 1, 126) * 6.8948 |
Result is in kPa (as RaceChrono expects) |
| Tire pressure FR | lowPass(E >> 1, 126) * 6.8948 |
Ditto |
| Tire pressure RL | lowPass(F >> 1, 126) * 6.8948 |
Ditto |
| Tire pressure RR | lowPass(G >> 1, 126) * 6.8948 |
Ditto |
| TPMS light on | (C >> 5) & 1 |
|
| Low pressure FL | D & 1 |
The FL tire pressure is shown in yellow when this bit is set |
| Low pressure FR | E & 1 |
Ditto |
| Low pressure RL | F & 1 |
Ditto |
| Low pressure RR | G & 1 |
Ditto |
Based on my limited testing, the order of tires matches how the pressures are displayed in the gauge cluster, i.e. correctly account for tire rotation, etc.
These values were read from a US market car where pressures are displayed in psi. I suspect that cars on other markets (using bar or kPa) will use a different scale in the data encoding. Please let me know if you find any data examples from non-US cars and I'll add them here!
Here's what the distribution of CAN IDs looks like in the CAN bus while idling in a parking lot for 10 seconds after driving for 10+ minutes:
| CAN ID (hex) | CAN ID (decimal) | Message count | Notes |
|---|---|---|---|
| 0x40 | 64 | 1000 | |
| 0x41 | 65 | 1000 | |
| 0x118 | 280 | 500 | |
| 0x138 | 312 | 500 | |
| 0x139 | 313 | 500 | |
| 0x13A | 314 | 500 | Not available on the ASC port |
| 0x13B | 315 | 500 | |
| 0x13C | 316 | 500 | |
| 0x143 | 323 | 500 | Not available on the DCM port |
| 0x146 | 326 | 500 | |
| 0x228 | 552 | 167 | |
| 0x241 | 577 | 200 | |
| 0x2D2 | 722 | 334 | Not available on the DCM port |
| 0x328 | 808 | 100 | |
| 0x32B | 811 | 100 | |
| 0x330 | 816 | 83 | |
| 0x332 | 818 | 83 | |
| 0x33A | 826 | 83 | |
| 0x33B | 827 | 83 | Not available on the DCM port |
| 0x345 | 837 | 100 | |
| 0x390 | 912 | 100 | |
| 0x393 | 915 | 100 | |
| 0x39A | 922 | 50 | |
| 0x3A7 | 935 | 100 | Not available on the DCM port |
| 0x3AC | 940 | 100 | |
| 0x3D9 | 985 | 50 | Not available on the DCM port |
| 0x500 | 1280 | 20 | |
| 0x506 | 1286 | 20 | Not available on the DCM port |
| 0x509 | 1289 | 20 | Not available on the DCM port |
| 0x50B | 1291 | 20 | Not available on the DCM port |
| 0x513 | 1299 | 20 | Not available on the ASC port |
| 0x515 | 1301 | 20 | Not available on the ASC port |
| 0x517 | 1303 | 20 | Not available on the DCM port |
| 0x640 | 1600 | 8 | These few were added after an OTA for the head unit? |
| 0x651 | 1617 | 8 | |
| 0x652 | 1618 | 8 | |
| 0x654 | 1620 | 8 | |
| 0x658 | 1624 | 10 | Not available on the ASC port |
| 0x660 | 1632 | 20 | |
| 0x663 | 1635 | 10 | These few were added after an OTA for the head unit? |
| 0x68C | 1676 | 8 | |
| 0x68D | 1677 | 8 | |
| 0x6B1 | 1713 | 8 | |
| 0x6BB | 1723 | 8 | Not available on the ASC port |
| 0x6CF | 1743 | 8 | |
| 0x6DF | 1759 | 8 | Not available on the DCM port |
| 0x6E1 | 1761 | 10 | |
| 0x6E2 | 1762 | 10 | |
| 0x6FB | 1787 | 10 | Not available on the ASC port |
| 0x6FC | 1788 | 100 | Not available on the ASC port |
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