2001 prius code p3001

I can't help you until you get your own, Prius aware, OBD scanner. Feel free to search this forum for the options. Sad to say, Ohio is not quite a 'day trip' from Huntsville so I can't run up to 'lend a wrench.'

Bob Wilson

 

I'd like to suggest reading the 19 module pair voltages while you're at it . . . 'carpe diem'.

Bob Wilson

 

Just to make sure:

• P3009 stayed with the vehicle after the battery swap and did not go with the traction battery?

Ok, now it becomes harder. The typical way of fault-isolating a resistance path to ground is a MEGer but these use high voltages to test insulators but these voltages are risky for electronics. If you have or can borrow a MEGer, disconnect MG1 and MG2 from the inverter and test the transaxle for leakage to frame ground without the inverter. Then test the cables disconnected from the inverter and battery. If no luck, it suggests the inverter may have a problem.

You're in a new area and we're interested in your progress.

Bob Wilson

 

Another approach to P3009:


The fault is found by finding the part closest to ground.

GOOD LUCK!
Bob Wilson

 

Bob, that looks like a nice technique. Is it possible the diagram has a couple small typos?

The large equation Vmeter = Vpoint * Rmeter / (Rmeter + Rleak) seems to be correct (if I'm looking at this right).

In working the example, though, you seem to have evaluated Vpoint * Rleak / (Rmeter + Rleak) ... which will give a very different result when Rmeter is large and Rleak is small.

Also (though this is only a quibble) the diagram suggests leak-to-ground (< 1 MΩ) and then the example uses a 5 MΩ leak.

I notice you use 14.4 V in the example, same as a pair of modules, just as the ECU voltage taps are laid out. Do you think this technique might lend itself to a quicker procedure by creating a deliberate leak of some known, safe resistance at one end of the battery, then using a scantool and the ECU voltage readings?

-Chap

 

I was more interested in sharing the technical approach and as you've pointed out, there are subtle aspects that need to be considered. Also, it presumes the existence of a single 'Hi Z' fault to ground and in the real world, there may be more than one.

My hope is we might collaborate on a general approach, perhaps one not so dependent upon having a MEGER. Better still, one that can handle ground faults outside of the traction battery as in this case.

What we want is a non-destruct, safe protocol for finding ground faults that may be in either the inverter or inverter-to-motor circuits. This is not a trivial problem but one I don't think is well documented in the maintenance manual (or my memory of those sections.)

Bob Wilson

 

Since we're talking about P3009, here's a procedure I've posted b4. It really seems like it should isolate the fault. No megger required. Here it is:

Prius P3009 High voltage leak code

I want to share a simple, but very accurate method of determining the source of high voltage leak codes on the Toyota Prius.
The first step is to clear the P3009 trouble code and then turn the key or push button to key on/not ready mode, (This is IG ON on a Gen I or the second position on the ignition switch (after ACC)) wait 30 seconds and if the code comes back, the leak is in the battery case. If the code does not set, turn key or push button to "ready mode"(start on the Gen I) and immediately shift to neutral and stay this mode for 30 seconds. If the code returns, the leak is in the power cables or inverter. If the code did not set, shift to drive and if the code resets now, the leak is in the transaxle. This is something that can be done in about minutes with a scan tool while never removing any components and not leaving the driver seat.

Keep in mind we're looking for the P3009 code to come back so a scanner of some sort is necessary.

Does anyone see any reason why this wouldn't work?

 

The only problem I can see is the unknown about how long a ground-fault has to exist before the code is set. I don't know that anyone has done that experiment ... but I may have occasion to in the future.

I'm seriously looking at an upgraded inverter for my wife's 2010 Prius provided I can find space to mount it under the passenger bench. IF SO, then I have no problem with tapping the traction battery as a power source to that inverter and with a high-voltage fuse (aka., think solar panel type), in it goes.

What I don't know is if the high-voltage terminal taps are going to see a ground-fault in the 3d party inverter so there will be a test.

Bob Wilson

 

Yes, you can unhook the two big orange connectors at rear of inverter and test to ground. If there's a leak it's usually so small you may not detect is without a megger (aka insulation tester). This is part of the full troubleshooting procedure in the Gen1 service manual, Arts talks about it a bit here.
Prius 1st gen - Replacing Transaxle

If P3009 is because of bad MG2 in the tranny, you may be able to detect it with a normal ohmmeter instead of a megger...since the winding are often burned up real good. Remove wiper cowl stuff, open the black rectangular HV wiring cover on the inverter. (this covers the orange MG2 wires).

Unhook MG2 wires from inverter, hold them "in the air" and test each of the orange leads to chassis ground with a regular Ohmmeter. If you have a bad enough MG2 the ohmmeter will register a dead short and no megger is needed....just a new MG2 stator

You can check MG1 HV wires too (the round connector) but I have yet to see MG1 electrically fail.

 

Judging by the test, it clearly points to the battery case. I know you put it in another G1 and it worked fine and I can't explain that.

The person who came up with this test is the owner of ReInvolt. You might try contacting/emailing him to see what he says.

If we look at this logically, putting the car in IG ON (not ready) would exclude the transmission and the inverter from the loop. With that in mind, we can only assume that a connection to the batt pack (in this car) is bad (since it works fine in the other car). The fact that the light comes on right away with IG ON, clearly points to the battery (and associated components) and away from the transaxle and inverter.

If it were me, I would try to isolate the batt case from the car (with a rubber mat or something) and see what happens. I would also try to contact ReInvolt to see if he could expound on the test and offer advice for your specific situation.

Pls know that I'm not anywhere near an expert and don't claim to be. I'm just a guy that is trying to come up with ideas to help you. Approach everything with caution and please double check my logic.

 

What did you observe that led you to conclude that? On mine, if I measure voltage at the 12 volt battery terminals, it does not change from the rest voltage (12.72 or lower) to the charging voltage (13.8) until the car is put in READY.

Another way to think about it is to remember that any power the inverter can use to charge the 12 volt battery must be drawn from the traction battery, and the system main relay doesn't close until the car is put in READY. That information's in the manual.

Hope this helps,
-Chap

Edit: hmm, do we know for sure that your system main relay actually opens when you turn the car off? An SMR stuck closed might explain various strange symptoms including your car charging the 12 V in a condition where ours do not. It would also complicate your diagnosis of a ground fault, to say nothing of endangering you in the process, so it's probably worth ruling out.