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'06 Prius... how far back and for how long are OBD codes stored?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by dslomer64, May 28, 2020.

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  1. dslomer64

    dslomer64 Member

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    I found codes P1116 and P1121 with an AutoZone OBD reader. They relate to a sensor in the coolant system.

    I know the traction battery is failing but didn't get a code for that.

    Toyota did no better except to come up with the code for the battery.

    Over 194,567 miles of driving, other codes had been stored and found.

    Should Toyota be able to find and provide to me a written report of all codes from the recent and far distant past as part of a vehicle diagnosis?
     
  2. ChapmanF

    ChapmanF Senior Member

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    Not to my knowledge. There is a "historical" status that some codes can be displayed with, but it certainly doesn't accumulate every code the car has ever seen, and I don't know what its exact rules are.
     
  3. Diemaster

    Diemaster Active Member

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    Per the OBD2 standard, some codes dont self erase and some do. The ones that do some take 40 warm up cycles and some take 80. (Not sure what a warm up cycle consists of on a hybrid though.)
     
  4. ericspoor

    ericspoor Member

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    The p1116 and p1121 i would think relate to a failed coolant flow control value, not a sensor.
     
  5. ChapmanF

    ChapmanF Senior Member

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    They relate to a sensor of the position of the valve. :)

    So when the ECM sends a command to the valve to move, and the sensor reading doesn't change, the ECM knows something is up. It doesn't know if the problem is with the valve or the sensor or the wiring to the sensor though. Still work for the human to do figuring it out.
     
  6. ericspoor

    ericspoor Member

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    ah good point.