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Inverter temperature CAN codes

Discussion in 'Gen 2 Prius Technical Discussion' started by Balt, Aug 17, 2010.

  1. Balt

    Balt Junior Member

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    Hi all,

    I've had an inverter coolant pump failure the other day (2007 model, 130'000km, 3.5 years old) with the lot of bells and whistles going off in the car. Self diagnosed easily with the software I wrote for my CAN bus adapter, however, I am not able to locate the CAN bus query code for the inverter temperatures.

    The Vass spreadsheet makes mention of a query code, but whatever data I'm getting back on those codes doesn't make sense.

    Does anybody know of a CAN codes list for the 2nd gen Prius that includes the inverter temps?

    Cheers

    - Balt
     
  2. RobH

    RobH Senior Member

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    The inverter temps are available in the reply to a 21 C3 query to ECU 7E2. The reply from 7EA is 61 C3 b6 b7 ... b35 b36. Depending on your CAN adapter, you may see an offset from my numbering of b6...b36, so you'll have to pattern match what you see to this data. It may be easier to count back from the last byte rather than the first.

    b6. b7. . . . MG2 RPM 0x0000: -16383 RPM, 0x3FFF: 0 RPM, 0xFFFF: 49152 RPM
    b12 b13 . . . MG1 RPM
    b20 b21 . . . Engine RPM 0x0000: 0 RPM, 0xFFFF: 65535 RPM
    B30 ... . . . MG1 Inverter Temp 0x00: -58 F, 0x4C: 79 F, 0x51: 88F, 0xFF: 401 F
    B31 ... . . . MG2 Inverter Temp
    B32 ... . . . Motor Temp No2
    B33 ... . . . Motor Temp No1

    These values were determined by forcing the sample values into the datastream that Techstream was measuring. Since the ScanGauge can't handle this long CAN message, I rather lost interest in decoding the rest of the message. I think an ELM 327 does ok with it though.
     
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  3. 2009Prius

    2009Prius A Wimpy DIYer

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    In other words it is impossible for ScanGauge to read the inverter temperature?
     
  4. RobH

    RobH Senior Member

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    Not using the message that Techstream uses to query it. :mad:

    That doesn't mean that the data isn't sent as part of other messages that I don't know about. And perhaps a software upgrade for the ScanGauge could be developed that would handle the longer messages.:flypig:
     
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  5. Balt

    Balt Junior Member

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    Thanks Rob! I'll give those a try.

    Cheers

    - Balt
     
  6. Balt

    Balt Junior Member

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    Hi Rob,

    I'm confused. Do you mean Byte by "b"? Each CAN reponse I get to a 7E2 02 21 C3 query only contains 8 bytes and they appear to be the same. So in order to obtain up to Byte 33, do I need to send "more data" requests (30 00 00 00 00 00 00 00)?

    Cheers

    - Balt
     
  7. RobH

    RobH Senior Member

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    The interface that I used just presented the 36 byte message. The long message must be a combination of several short messages. The ELM 327 documentation has something about optionally displaying long messages. The term "multi-frame message" has been mentioned here, but I've never had to learn about it since my interface takes care of it automatically.

    Sure, go ahead and send the "more data" request. My car has survived worse... The only messages that would worry me would be 10, 27, 30, 3B, and A5 commands (positioned where the 21 shows up), as they can set things. Any 21 command should be safe.

    When you get the CAN interface working, the KWP interface is just begging to be decoded. Several fun KWP messages that I've seen are 8340f0300110 (Security Horn ON - turn off with same message except final byte is 00) and 825bf0211806 (Query passenger weight). I'm not sure which of those two are potentially more dangerous :D .
     
  8. vincent1449p

    vincent1449p Active Member

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  9. 2009Prius

    2009Prius A Wimpy DIYer

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    Wow thanks for the good find! :) Looks like someone made an exhaust list of the CAN requests/replies for all systems in his 2006 Prius. The list seems to agree with what RobH has kindly published so far.

    Now it would be great if there is a corresponding list of all the "passive" messages that are already present on the CAN bus (no requests needed - no delays, think "real time"). Vass has done a lot of good work on this but we are still missing some critical parameters, for example ignition timing (IGN) and inverter temps. Any Toyota insiders willing to share some secrets? :D
     
  10. The Tramp

    The Tramp Italian Prius Expert

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    Does anyone know which is the maximum temperatures that the inverters can tolerate?

    I've blocked the grill and seen temperatures overtake 50°C (120°F), got scared and removed a few elements.
     
  11. JimboK

    JimboK One owner, low mileage

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    I raised this question some time ago. You should be good at temperatures substantially higher than that. I use 150F as my cutoff, which still provides a pretty good safety margin.
     
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  12. The Tramp

    The Tramp Italian Prius Expert

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    Thanks Jim, I did do a search but I did not find your thread.
     
  13. 2009Prius

    2009Prius A Wimpy DIYer

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    I think for the electronics the cooler the better. I too would be worried and take some blocks off if I saw sustained 50C or above. On the other hand if it is just short pulses of high temperature then I won't worry too much about it. Good luck! :)