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Need Help with P0A94 for 2013 Prius C

Discussion in 'Prius c Main Forum' started by PriusCamper, Oct 29, 2022.

  1. PriusCamper

    PriusCamper Senior Member

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    Trying to help out a Florida man with these error codes. At first I thought it was just the inverter pump, but then I realized it wasn't a regular Prius but a Prius C and if you try to Google search for this problem specific to Prius C you get flooded with regular Prius links that aren't Prius C...

    I've tried all I can to figure the diagnosis steps for this...

    Maybe @SFO or @Elektroingenieur has the diagnosis write up & repair from the manual?

    Is the inverter issue with Gen3 Prius the same with Prius C?

    The codes come back right away after they're cleared...

    f40f88a8-3cf8-4802-8632-a044af17cb65.jpeg
     
  2. Elektroingenieur

    Elektroingenieur Senior Member

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    For DTC P0A94, DC/DC Converter Performance, the Repair Manual (more info) gives more than a dozen different procedures, each for a specific INF (information) code, which should be available in the freeze frame data. Some of these procedures just direct the technician to replace parts of the inverter with converter assembly, but others have extensive checks of connectors, wiring, sensors, and so on.

    As you may know, DTC C1259 is the skid control ECU acknowledging a malfunction reported by the power management control ECU; since you also have that DTC, you can ignore this one.
    As far as I know, none of those recalls, campaigns, or legal settlements applies to Prius c models.
     
  3. Sonic_TH

    Sonic_TH Active Member

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    The car can't move?
     
  4. PriusCamper

    PriusCamper Senior Member

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    For the moment, yes...

    He's a diesal mechanic and new to hybrid systems and spent this Saturday at the shop trying to figure what was wrong. He pulled the inverter and inspected inverter pump and hasn't found anything wrong yet. I've been texting with him...

    It's his wife's car and she got stranded and they had it towed because red triangle wouldn't clear.

    Currently trying to help him test the hybrid battery to eliminate that as the problem before he re-installs or replaces the inverter.

    So any diagnosis options that can help with a Prius C that can't currently be powered up would be useful.

    I wonder if @Leadfoot J. McCoalroller is still around? He seems to know more about Prius C than most...
     
  5. Elektroingenieur

    Elektroingenieur Senior Member

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    The HV battery isn’t listed as a trouble area in any of the P0A94 procedures. (The procedure for P0A94-587 mentions “battery smart unit,” but not the HV battery itself.)
    Can the scan tool find the stored INF code? If so, that’s the easiest option, since it distinguishes between situations that may require dozens of further checks of high-voltage and low-voltage components and wiring (as with INF codes 127, 172, and 549, among others), and those in which you can skip ahead to replacing parts of the inverter with converter assembly, immediately (as with INF code 590) or after one or two tests.

    I’d also suggest that it’s worth $20 (or less, if you have a library card) to use the Repair Manual from Toyota: many of the diagnostic steps are hyperlinks to other procedures, and for readers unfamiliar with hybrid systems, the manual points out which steps need to be done while wearing insulated gloves.