Hello. My Wife was driving our 2001 Prius and got the big triangle and the car went into limp mode. The Codes were P3100 (info code 196) and P3125 (info code 325) P3100/196 = Internal Error - Generator CPU Malfunction 3125/325 - Inverter Internal Short. - Generator Inverter Fin - Inverter Internal short Clear the codes and the car runs fine, but the problem will eventually resurface. The dealer wanted tor replace both the converter/inverter and HV ECU. I purchased replacement converter/inverter from Ebay and inverter coolant pump (new) and installed. Problem eventually resurfaced. I purchased replacement HV ECU from ebay and installed. Engine would not start (does not attempt to even turn over), but was not throwing any codes. I had this same symptom with a third HV ECU as well. The part numbers on the HV ECU were exact matches. Questions: 1) Is there something I have to do after installing a different HV ECU in order to get the car to start again? (This is the ECU in the front passenger footwell) 2) I thought the HV inverter might be plausable as source of the problem. But I really doubt the HV ECU is at fault. My current prime suspect is the MG/Transmission unit. However if anybody has any great ideas on how to actually diagnose this failure, please let me know. I have more tools and electronics experience than most (have oscilloscope and am not afraid to use it ). Thanks in advance for any guidance. Mike
Also, does anybody know of a Prius Tech in the Minneapolis area who really knows there stuff. Somebody who can go beyond, well the computer says we should replace inverter and HV ECU? Thanks again, Mike
I believe the HV ECU and Immobilizer ECU need to mutually authenticate when first installed. I think if you change out the Immobilizer ECU, there is a required period of leaving the ignition ON for something like 30 minutes to make the new immobilizer pair with the HV ECU. It might only work when it's in the unpaired state, not when it's been paired before. I don't remember whether it's the same procedure if the HV ECU is what's changed. There are details in the manual (hardcopy or on techinfo.toyota.com). When they're not properly paired, I think the symptom is the same as what you're seeing: HV ECU will not even try to start. Hope this helps, -Chap
Yep, that got me past the hurdle. Thanks Chap. Now I just need to wait for the original problem to reappear. Even though I replaced all the parts the dealer said needed replacing, I just have a sneaking suspicion the problem is in the MG/Transaxel unit or the wiring harness. Mike
Hi Mike, I assume you are using Techstream. Beside DTCs and info. codes, did you save the Freeze Frame Data before clearing the DTCs? FFD captures all the important metrics for the conditions at the time the malfunction occurred. It may provide some clues to what actually triggered the DTCs. It is a good practice to save the log files before clearing DTCs. Vincent
I've seen P3100 and P3125 multiple times. If you had P3100/175 and P3125/287 I would guarantee your transaxle (or possibly wiring harness) is toast...even though the manual says bad inverter or HV ECU. Too many people have swapped inverters/HV ECU's only to find they are wasting their time (and money).
Is there a way to get the Gen 3 Technical Manual? I went to the Toyota TechInfo site but it requires a login?
Yes, it does, so that's what you do. You can feed your subscription $15 at a time, giving you access for all you can read/download in 2 days (technically more than that if across a weekend, I believe) or $75 for a full month. I just bought a new (to me) Gen 3 last month and I found the $75 subscription really handy while I was getting to know the car. My month is used up now. There's no requirement to stay continuously subscribed, you can let it lapse as long as you want, and feed it again any time you want a couple days of access. Once you're logged in, use the TIS tab at the top of the window (technical information service), then you can enter your year and model, and search. There are several tabs below that, here are the ones I especially commend to your attention: NCF: the New Car Features manual. This is what tells you all about how your car works, what the important components are and what they do and how they relate to each other, theories of operation, diagrams of the CAN and LIN and AVC-LAN buses, etc. If you sign up for techinfo and never read anything else, read this. RM: the Repair Manual, the thing most people are after when going to techinfo. It is very complete and hyperlinked. Bear in mind, it covers how to diagnose/troubleshoot, remove, disassemble, assemble, and install everything, but it doesn't contain much review of what the things are for or how they work; it assumes you know that's in the New Car Features manual. EWD: the Electrical Wiring Diagram. This is a really cool showcase of what you could do with a wiring diagram online instead of on dead trees. For example, hover over connectors in the 'location and routing' section and see what they connect to, or click on any wire on any diagram page, the components at both ends start to blink, click the info button, and see the connector shapes, pinouts, part numbers, links to the location and routing page telling you physically where they are in the car, and to other system diagrams they are mentioned in. In addition to those tabs, there is one for service campaigns/TSBs, one for collision repair (all about the kinds of repairs that involve cutting/welding/brazing; anything you can repair with screwdrivers and wrenches is already covered in the Repair Manual), and a Quick Guides tab (deeper technical tutorials on lots of specific topics). There is also a Technical Training section where you find various online books organized by Toyota's training course numbers, say, all about their braking systems, or evaporative emissions, or whatever. -Chap Edit: I should mention the thing that took me longest to figure out about how TIS is organized. The part where you enter your model and year, etc., and other categories/keywords if you want, really is a search. When you enter that info, then go to any of the tabs (repair manual, say), what you see is a flat list of manual sections that matched the search ... not a nice table of contents for the manual. The trick is, just pick any of those sections, doesn't matter which. You'll end up in a new window showing the repair manual at that section, but it'll have the whole manual's table of contents on the left, in order, properly organized as a tree. That's the way I prefer to browse, so once I get there I pretty much use that, and don't go back to the 'search' window much.
Ok will give that a try piece meal so to speak. I've got lots of disk space to can download like crazy and read at leisure. Thanks and if you have any tidbits on CAN Bus deciphering/understanding please let me know. I'm a geek at heart so throw it at me but do please explain acronyms as I get lost in those since I don't work in this field and my own field has lots of acronyms Marc
After replacing the HV ECU, you will need to sync with the immobilizer. To do this turn the key to On, came back more than 30 minutes later, and it will be synced. However, this also resets what is considered "Full" to the fuel guage. So, it should only be done with a Full tank, or you'll have to repeat it once you fill up again. This procedure is documented in the Repair Manual (RM778U) on Page BE-104 Step 2b.
