Need help with Custom PIDs for Gen 3 Electric Water Pump (21D7) in Torque Pro

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Asfand, Apr 28, 2026 at 6:09 AM.

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  1. Asfand

    Asfand New Member

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    Hi everyone,

    I’m currently troubleshooting a potential overheating issue on my 2010 Prius (Gen 3) and I need some help verifying the custom PID settings for the Engine Electric Water Pump.

    I’ve been using Torque Pro with the standard Prius PID lists, but the Electric Water Pump (Actual vs. Target RPM) isn't showing up correctly. I’m specifically trying to monitor PID 21D7 on Header 7E0.

    What I’ve tried so far:

    Header: 7E0

    Command: 21D7

    Current Equation: (D*256)+E

    The Result: I’m getting very high raw values like 18176 (Actual) and 8449 (Target) during normal driving.

    I suspect I have the wrong multiplier or byte offset for the Gen 3. Does anyone have the verified Equation to convert these raw values into actual RPM?

    Also, if anyone has the verified PIDs for the Water Pump Amperage or Duty Cycle to help me see if the pump is cavitating or hitting a blockage, that would be greatly appreciated.

    Thanks in advance for the help!
     
    #1 Asfand, Apr 28, 2026 at 6:09 AM
  2. PriusCamper

    PriusCamper Senior Member

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    Torque might not have that PID, but its a smart one to have. Basically anything that can monitor the details of the electricity going to that pump would be helpful.

    I know CarScanner Elm app does better at communicating with all the system and Torque is a very old system that doesn't get updated much (if at all). Also the Autel AP200 OBD2 reader does complete diagnostics equivalent to Toyota Techstream.
     
    #2 PriusCamper, Apr 28, 2026 at 6:28 PM
  3. StarCaller

    StarCaller Senior Member

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    The raw values are high because the equation is missing the 0.25 multiplier /
    Use ((D*256)+E)/4 for the correct RPM /

    At 16 years old, that pump is at the end of its service life /
    A new pump is cheap insurance; a warped head or a replacement engine is not /
    Do not risk the car to save a little money /
    Just replace it with an OEM unit /
     
    #3 StarCaller, Apr 28, 2026 at 8:51 PM
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