PID: 227028 Ambient Air Temperature?

[electricsidecar-dev]

Header: ATSHDA60F1

Example response:

18DAF1601039627028F8FC00
18DAF1602100000004040000
18DAF1602200000000000E00
18DAF160230B07FF00000000
18DAF1602400000000000000
18DAF1602500000000000000
18DAF1602600000000000000
18DAF1602700000000000000
18DAF1602800005555555555

In hex form:

F8 FC 00 00 00 00 04 04
00 00 00 00 00 00 00 0E

00 0B 07 FF 00 00 00 00
\---/ AAT, signed 16 bit value (Celsius or Fahrenheit, depending on dash?) 

00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00

https://github.com/ElectricSidecar/Acura-TLX/blob/1e0c347b2e4328c589c21ec8cc17304c7b4701e7/signalsets/v3/default.json#L9-L12

https://www.ridgelineownersclub.com/threads/custom-pids-for-odb-scantool-app-like-torque-or-carscanner.229500/ indicates that Signed(Q,R) might be Outside Air Temp. QR in the example are 000B -> 11, but need to confirm this is the actual temperature from when this reading happened.

[electricsidecar-dev]

@sidbmw to confirm the above and share any more readouts!

[sidbmw]

Yep it's 8C outside with a peak of 11C today so this seems correct. I was in the garage when I sent you the logs so a bit warmer than 8C makes sense.

[electricsidecar-dev]

SHA: 1e0c347 merged in if you want to give it a try! Also it would be helpful to test if your dashboard settings do actually affect this parameter. If you're able to change to Fahrenheit somehow and then try reading the value again. I'm hoping it's always outputting in Celsius but this parameter might be reading straight from your dash, which will make it a bit tricky for Sidecar to know how to treat the value 🤔

[sidbmw]

Will do. Pretty sure there isn’t a way to change units in this car. I spent a good amount of time trying to change the tire pressure unit to psi from kPa 😅. Do all temp related units assume Celsius? I remember seeing exhaust related values over 700C which I don’t think is accurate. Makes more sense in Fahrenheit.

Based on the VIN isn’t it possible to figure out where the car was sold/made for? With that maybe you can set the default temperature units. Using gps location and/or phone region could work too I think but you’d have the edge case of imported cars? Travelling would also cause an issue if the above was used.

[sidbmw]

Just edited the above comment and it disappeared from the app. Bug?

[electricsidecar-dev]

Oh, odd, I see the comment in Sidecar; is it still not showing for you?

[sidbmw]

I see it now

[sidbmw]

Ok can confirm the temp shown in the app aligns with what the car shows (18C in this case). Sent you logs as well.

[jverkoey]

Awesome :) We can leave this issue open in case we ever figure out what the other bytes in this parameter mean.