Posted to Technical Discussion Forum on 8/30/2009
Electrifying Prius - P3009 HV Leak
This vehicle is not fixed but has been diagnosed. I'm not
looking for answers as to the cause of the failure but more
interested in what the logical approach to find the cause of
the failure would be.
I was called in to to help with this one, it is not at my
shop. Originally, the car came in with a P3009 code. During
the course of the diagnostic, it became a no-start. That is
when I became involved with it.
Note: They did indicate that the auxillary (12 volt) battery
was disconnected during the course of the P3009 diag.
What I first did was a Health Check.
Next, I pull all the DTC's from the modules and their
respective Freeze Frames.
HV ECU DTC
HV ECU Freeze Frame 1
HV ECU Freeze Frame 2
HV Battery ECU DTC
HV Battery ECU Freeze Frame
Engine ECU DTC
Engine ECU Freeze Frame
The P3009 code indicates that there is a insulation leak in
the HV circuitry. Unfortunately, it doesn't narrow down the
area of concern, it could be in the HV battery, the
inverter, the frame wires, or in the transmission. In order
to test for the P3009, it would involve HV leak testing with
a megger, but that means each of the components would have
to be isolated from each other. This could be very time
Techs in dealerships and in areas where there are a larger
number of Gen I Prius'es have probably dealt with this code
and failure a number of times now. It seems to be a pretty
common failure and I'm sure some have struggled with it,
while others probably have a good system in place for
chasing the failures down. I've not seen discussed in these
forums before so I thought it would be a good time as any.
How should we approach this vehicle to confirm an exsistence
of a HV leak and narrow it down to a certain area so we
don't have to blanket test?
Is the no-start related in some way to the HV leak?
Does the P3009 Freeze Frame help in any way, to determine
the area of concern?
What other data that I haven't provided, do you think would
Thanks in advance,
Harvey from British Columbia
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