Gen 1 HV BATTERY REBUILD WITH 2G CELLS

Correct. Run a 1 A or even 0.5 A experimental. Several cycles of charge/discharge and see if you can't get the Ahr capacity back up. What you are doing are called 'conditioning cycles.' But try anything in between. You've joined the 'bleeding edge.'

Bob Wilson

 

Yes, it makes sense to check the wiring harness to the HV ECU and the inverter. DTC P3100 does imply a hybrid vehicle ECU fault or a wiring harness problem.

The traction battery ECU is plug and play but I do not think that is an issue, if P3100 and P3125 are the only codes being logged now.

When the car is READY, measure voltage across the 12V battery. Is it ~13.8V? If not then the DC/DC converter is not working and the inverter probably needs to be replaced.

I think that you should subscribe to the Toyota Europe website that provides repair manual info so that you have wiring diagrams and repair manual info available to you. I really think that you need this.
Toyota Service Information

I don't think that you wasted your time by working on the traction battery since some of the codes in your OP no longer are present. It seems likely that your car has multiple issues.

If the inverter coolant pump is working properly, you should see a step in the fluid level within the inverter coolant reservoir. The level at the front of the reservoir should be higher than the rest of the reservoir. You should also hear the coolant pump when the car is IG-ON or READY, and it sounds like an aquarium pump. You should not hear any air bubbles.

 

No, the READY light will come on when the car is ready to be driven, which means that it has been started. The gasoline engine will normally run for a few minutes to warm up, and the length of time depends upon ambient air temp.

The level at the very front of the inverter coolant reservoir should be higher than the level elsewhere, when the pump is running.

The diagnostic portion of the repair manual is certainly helpful, but if you aspire to check the wiring harness then you will need the electrical wiring diagram for your model year.

 

I had to run 240 mile round trip today (384 km) so I'm a little tired. I'll try to address these question and comments in the morning:

Bob Wilson

 

Sometimes I get busy at home. So let's go over good status:

• 13.8 V - inverter DC-DC converter is working
• engine runs - MG1 has to be working
• engine charges the traction battery - good, keep it running
• inverter coolant pump is working - good

Now lets go over the bad news:

• P3100 - HV ECU malfunction
  • Check and reseat connectors - again there are a long list of subcodes but without a Techstream, they are not otherwise available.
• P3125 - Converter & Inverter Assembly Malfunction
  • Huge list of subcodes, pp DI-271-306 this is where the Toyota Techstream provides a roadmap. This is where getting the codes from a Toyota service center pays off. Start with checking the connectors.
• ABS light - this controller will flash the error codes if you use the OBD connector jumper technique described in "AE Pig-tail and code flasher"

The inverter has the power electronics that operate under control of the HV ECU. The problem is without the subcodes, you wind up having to measure the different signals only there isn't a whole of details about what those signals should be or look like ... and there are a ton of them.

Since the engine starts, MG1 has to be working as is the engine ECU.

That "reverse" fails suggests MG2 has a problem. Reverse is handled by MG2 alone. So I would concentrated on the MG2 sensor signals that feed the HV ECU followed by checking the MG2 power signals.

Now MG2 and MG1 have to work together to provide motive power. So I wouldn't try to do any driving until the MG2 is figured out.

Bob Wilson

 

Late thought, the Prius MGs uses a synergy drive encoder to measure position. Two coils with an AC signal are at 90 degrees relative to a 'cam' disk and two other coils pickup the AC signal. These pickup signals are used to measure the rotor position. So you should find an AC signal from the HV ECU that feeds the drive coils and if you had an osciliscope, you could see the sense coil return signals. But the rest of the signals, sad to say, are poorly documented.

Bob Wilson

 

There is no such thing as a "synergy drive encoder". The Prius uses a resolver. The information is right there in the repair manual, as well as the New Car Features manual. It's also available online. Search for "Prius" and "resolver".

Resolver issues are covered by a different code, which the OP has not reported. Again, this is in the repair manual. And the complaint - the vehicle will not move in reverse - does not, at this time, suggest a MG issue. The problem could be in the battery, the inverter, the transaxle, or the control system. The OP's next step is to find the information code related to P3125.

No, they're not. Again, the information is available from Toyota's service information.

The reason that I am harping on this point is that you have mentioned many times that you own the repair manual. However, this is not apparent from the advice that you dispense. Your diagnostic advice will be greatly improved if you check it against it the information contained in that manual. Folks who follow your advice will then will be less likely to purchase components that they do not need. Keeping in mind that most Gen I projects are undertaken on a limited budget, that would be a good thing.

Simply put, you have the tools. All you need is the willingness to pick them up and learn.

 

Thank you! I had left the datasheet at work for the "Smartcoder (AU6802N1)" which is described at an R/D (Resolver to Digital) conversion IC used with a brushless Resolver (BRX*) such as Singlysyn, Smartsyn, e.t.c." "synergy" "Singlysyn" or "Smartsyn" . . . whatever you call it, it is an excellent technology:
http://www.docstoc.com/docs/41831883/Development-of-VR-Resolver-system-for-hybrid-electric-vehicles

The key is this particular part uses a 10kHz signal that is picked up by two coils at right angles around an offset disk. This is the same principle the resolvers for MG1 and MG2 work.

As for the HV ECU signal definitions, feel free to offer them. Or how about something of value that he might use to diagnose the current problems. Go right ahead! <LOL>

Bob Wilson

 

Again, the codes on this vehicle do not indicate a resolver issue. However, even if they did, the chip that you describe is not used by the Gen 1 Prius. If you have a Gen 1, you can confirm this for yourself.

No. It's not "whatever you call it", it's an error. If someone with a broken car is told that their problem may be related to a "synergy drive encoder", then it is quite possible that they will waste time searching for information on such a device. I'd rather not see that happen. Hence, my post.

Google "synergy drive encoder", in quotes, and see what you find.

Now Google "Prius" and "resolver" and see what you find. Big difference.

To be blunt, it appears that you are copying information off of the internet and presenting it as knowledge. In this case, you have copied information that has been poorly translated from Japanese. Because you don't understand it, you cannot correct it. Please, take the time to learn how something works before telling folks "how it works".

Again, they are in the repair manual, which you have stated that you own. If you are unwilling to look them up and share them, I doubt that other folks will do it for you. But as I have mentioned, the first step is to find out what information codes are present in conjunction with P3125. Let's stay focused here.

Actually, if you had read the post all the way through, you would have seen that I have already done that. The OP is now aware, among other things, that the vehicle's symptoms do not necessarily indicate a motor issue, that getting the information code associated with P3125 is at this point the priority, and that there is no such thing as a "synergy drive encoder." With this information, the OP can avoid wasting time and money as they work to get their vehicle running.

 

Are you still working with just a volt-ohm meter?

The reason I ask is a couple of years ago, I was looking at an HV ECU for another project:
Prius Hybrid Vehicle ECU

On the North American NHW11s it is located on the right-hand side floor board. So one thought I had was to go to my car and start reading the DC and AC signals associated with MG2 and post them here. I can also capture some signals using the audio inputs to my Mac to show waveforms.

I just don't know if the UK NHW11s have the HV ECU in the same location and thus behind the brake and accelerator pedal assembly.

Were you able to get a good mapping of the engine compartment fuse and relay boxes to verify everything is OK?

Just to make sure we're on the same page, you can start the car, the engine runs, and it goes into "READY" without any other error lights? If you restart the car three times and keep it in "P", it appears to be OK until you try to shift it into any drive gear?

Bob Wilson

 

An independent shop with a Mastertech or a recently updated Snap-On scanner should be able to pull the information codes on a Gen I Prius. However, unless the technician is familiar with Toyota hybrid diagnosis, you may have to explain the existence of those codes to them. The information codes can be found in the freeze frame for the regular codes from the HV ECU.

Note: Some folks on this forum tend to dismiss the usefulness of freeze frame data. Ignore them. You want to get your vehicle running.

Hard to say without looking at your car, but many vehicles have empty slots in their fuse boxes.

I would recommend getting the information codes first.

The engine can assist in drive, even with limited power to MG2. That's why you are getting motion. In reverse, it's MG2 alone. So if the system sees any reason why it should not produce normal torque - battery, inverter, or motor issues - it limits output.

The assertion from bwilson4web that "reverse fails suggests MG2 has a problem" is incorrect. At this point there is simply not enough information available to determine this. Remember, many folks who offer advice on this forum are guessing, and have not actually diagnosed problems such as yours.

Don't worry about that right now. Regenerative braking is often disabled when there is a major problem with the hybrid system. That's probably what is happening with your vehicle. When that happens, brake warning lights come on. You probably have a C1259 code in the brake ECU. If so, that code will go away when the root problem is repaired.

 

Thank you!

It is often easy to lose context in a long thread. It sounds like if we can solve the reverse problem and ABS stuff, you would be 'home free.'

It really sounds like you're getting close. So the car moves forward OK?

Now the shifter has two mechanisms for signaling the gear (doing this from memory, schmatics at home.) There is a resistor network and if I remember correctly, a parallel set of discreet lines to the HV ECU. Just speculation but if one or the other of these parallel mechanisms were failing, you're supposed to get an error code. Both sets of lines head to the HV ECU. As redundant systems, they minimize the risk of a single failure causing the car to become 'shiftless' or 'unexpectedly shifty'. That would be shifty problem at high speed.

Bob Wilson

 

At present, there is nothing to suggest a shifting mechanism or signal problem.