custom PID help

I'm looking at adding some custom PIDs to RCP which I've tested in Torque pro (info was in a torque specific thread) which shows the correct values.

However using the same in RCP, shows maybe half the value that torque does?
Torque setup, which returned around 32c which seems correct based on a sunny 20c day.
IAT1 (post-intercooler):
PID: 0168
LONG NAME: Intake Air Temp
SHORT NAME: IAT
MIN VAL: -40
MAX VAL: 300
SCALE: x1
UNIT: °C
EQUATION: B-40

RCP:
channel: Intake Temp
postfix: none/none
PID: 0x0168
source data: 0x0000
equation: B-40

RCP first test showed null output. using 'Test connection' showed a value of 17. unfortunately i ran out of time to test any further at work. Do i need to do something with the source data field maybe?

Comments

  • edited August 2019
    Source data is the value to which the equation is applied to. If you enable the test connection you will get "real" source data from the device.

    I'm interested to hear what the real source data is when the test connection is enabled.

    Max value should be 215 with that equation, so 300 seems a bit strange.
  • had a quick play away from the car, yep, FF would be 255, so -40 and that gives 215.
    gotta love forum info! i guess 300 was just high enough so the real data was within that limit.
    i'll try again on the drive home and let you know...
  • no luck last night. double checked the setup in RCP and it looks right. i've got 3 custom PID's, coolant temp and pre&post intercooler Intake air temps. 'Test Connection' shows correct value for coolant temp, but fixed 009 for both the IAT's.

    0x0167, B-40 is for coolant.
    0x0168, B-40 for post IC, and C-40 for pre-IC IAT's.
  • What is the ’source data’ for IAT PID when using the test connection?

  • edited August 2019
    both show 0x0000.
    seems weird to me that the 'vehicle profile' screen shows 009 when using Test Connection, but live data shows 0x0000.
  • edited August 2019

    Are you able to connect the OBD-II reader using the Bluetooth Terminal app (assuming you're using Android, and have Bluetooth OBD-II reader (not Bluetooth LE or Wi-Fi)? I'm curious what happens if you do:

    > ATZ

    > 01 00

    > 01 67

    > 01 68

    Type commands without the >, it is the ELM 327 prompt.

  • https://play.google.com/store/apps/details?id=com.dev.aproschenko.bluetoothterminal

    Carista> >
    Carista> 41 67 03 65 44 CR
    Carista> 0167 CR
    ME> 0167 CR+LF
    Carista> >
    Carista> 41 00 B6 3D A8 13 CR
    Carista> 0100 CR
    ME> 0100 CR+LF
    Carista> >
    Carista> 009 0: 41 68 03 59 4C FF 1: FF FF FF 55 55 55 55 CR
    Carista> 0168 CR
    ME> 0168 CR+LF
    Carista> ELM327 v1.5 >
    ME> atz CR+LF
    ME> Connected to Carista
    ME> Connecting to Carista

    23c ambient air
    46c oil
    torque: postIC (B-40): 49, preIC (c-40): 36

    super useful tool that, might come in useful trying to stumble upon other useful PIDs on the car
  • Thank you for this. Looks like RaceChrono is having trouble with that response for 0168. I will investigate.

  • The response is in unsupported format. I will fix this issue for upcoming v6.1.
  • excellent. thanks!
  • RaceChrono v6.1 has just been uploaded beta group (Android only). It has support for multi-frame responses, so this should be fixed now.
  • 6.1beta is working - matches TorquePro values.
    thanks!
  • Great, thank you for feedback
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