Newbie. Bought an '05 & promptly killed it.

While the ICE is no doubt a bit tired, the thing that taxes it going up the mountains is a worn out HV battery.

If you want to work on the Prius, you will need a good scan tool and something like VxDiag Nano for Toyota and a cheap laptop will give you the equivalent capability as a Toyota dealer.

Once you can read all the codes, it will be clear what ails it.

As far as R&R on the ICE, used engines are cheap and plentiful, so it cheaper and easier to just do an engine swap.

 

The goofy snowflake in the road is just an information icon to let you know it's cold outside and to be wary of frozen roads. It has nothing to do with anything else, so have no fear of it.

As mentioned before, you most likely have a weak HV battery/module going bad/etc. Although the engine has many miles, I seriously doubt that is the cause of any of your speed issues. If the rings were bad enough to cause you to slow down like you did, you'd have a smoke screen behind you and you'd have probably seized the engine from not having any oil left. It's the battery.

 

The fact that you don't mention the state of the hybrid battery usually means that's the problem. You are new to the car and lets be honest best of intentions but clueless. Nothing stresses the Prius Hybrid battery more than a big nice person mountain and will take out a 13 year old battery really really quick.

You are not alone. Countless posters come on here after buying a 10 year old Prius in your case a 13 year old prius for its gas mileage and get boned by the battery. Its the number #1 post here. Its the reason it was sold. By a very nice concerned man lol.

Do not replace anything. Take the hybrid battery out of the back of the car and like hundreds and hundreds of posters here read up on how to diagnose it and repair it. It makes no sense replacing anything if that battery is not working well. Because if you cant handle that technically and financially nothing else matters.

Without a good working hybrid battery the car is worthless.

 

There is nothing wrong with the electric motor. Motors don't wear out and lose power like engines do. They just quit.

It's likely the battery. Or some other part of the traction battery system. I wouldn't trust a single diagnosis of the battery pack. You don't know the skill level of the tech, or the issues to look for.

BTW, there are two Motor/Generators in a Prius. MG1 and MG2. They are connected to the ICE via a power split device (which is NOT a CVT). Once you understand how the ICE and MGs work together (and the ingenious simplicity of the system) you will laugh at the crude puzzles of components that power other automobiles.

Think of the dream vehicle that you have: No starter motor, no clutch, no alternator, no serpentine belts, no transmission (see power split device), brakes that last forever because the regenerative system slows the vehicle, electric scroll compressor air conditioning that does not need the ICE, etc.

Keep us posted on your progress.

 

IS THERE TRANS FLUID/DIPSTICK IN THESE?

No. The transaxle is sealed. Fluid just needs to be changed every now and then (it's a lifetime fluid per Toyota, but typically 60k/100k miles depending on personal preference.

Frankly, the loss of power felt like the ECU-induced "limp mode" that later-model cars slip into to prevent catastrophic overheating

It very well may have been a "limp mode". This will happen depending how bad the battery has degraded. Kind of the same theory about catastrophy.

In Reno, the indie shop's hybrid OBD showed ALL good cells with nearly-matching voltage (16.XXvdc if I'm remembering correctly).

Unfortunately, a static voltage check could mean jacksh*t for a hybrid pack unless a module is seriously gone. An early failing module may not show a voltage problem. I had a module in a customers pack that was arcing out the side and still showed the same voltage as the modules around it. At 16.x volts per block, he's may have been measuring block voltage while it's being charged by the hybrid system. That can cover up a lot of problems.

Before you undertake a significant procedure, we could really give you the best advice if you were able to post the actual DTC codes and any subcodes/freeze frame data from the car. Without real codes, we're just giving you 'most likely' scenarios based of our experience.

 

The revving is, once again, indicative of a weak/failing hybrid battery.

You are correct, the codes you're showing, which were probably obtained from the MFD (touch screen display) have nothing to do with real engine/HV system/etc DTCs.

Any questions you have about the battery construction can be answered by YouTube. There are literally HUNDREDS of videos available demonstrating the disassembly of a Prius HV battery

 

You will probably get around for a while with the lame HV battery, but it won't be any fun and sometime soon the car will stop and you'll have to have it towed. And you never know when or where it'll happen.

I recommend getting reliable diagnostic codes and sub codes with a reader made for the car to verify the problem. There are lots of threads here about that. If it's the battery, I don't think I'd buy a new one for a car that old. Nor would I get a refurbished one, even if I was going to sell it immediately. I couldn't live with myself if I did that to someone. They don't last long. A near-new used battery is probably the best compromise, but make sure it's not one that someone else refurbished. If you want new, the list price from Toyota is now only $1,600 plus installation if you want the full warranty. So a 2015 battery with original cells, should cost substantially less. @2k1Toaster offers a good alternative to the new Toyota, but I don't know what he has in inventory right now.

And hopefully, this will help with some of the acronyms we fling about.
PriusChat Glossary | PriusChat

 

Retail, over the counter price is closer to $2,000.
Some ships may get wholesale price near $1,600.

Don't forget that these are not fully assembled batteries. Please buy the proper tools to correctly tighten the nuts for HV connections.

 

Thanks Eric. I was going from memory from what I've read around here. But you actually buy them, so I appreciate the first hand info.

 

Yes, many use ICE for engine.

The transmission is in a transaxle, combined transmission and differential.
The buzz word for the combined transmission is Hybrid Synergy Drive, the engine and two Electric motors/generators are connected to a planetary gearset called the Power Split Device
M/G2 is directly geared to the wheels, when it moves, ithey moves. It is usually a motor driving the wheels. Durring braking it is a generator, charging the High Voltage battery. (There are odd conditions that make it a generator even when cruising)
M/G1 is the starter and most frequently, the generator. (the odd conditions above use it as a drive motor, a sort of overdrive)

You are always really in D, the shifter emulates the other gears.
R just rotates M/G2 backwaards.
N just depowers both M/Gs, try to avoid N as nothing charges in N
P inserts a pawl in the gears, stops the wheels from turning
B adds engine braking, for long steep downhills (more than a 600 foot vertical drop) Someone at Toyota was too honest to call it L but you use it like L. The harder you depress the brake pedal, the louder the engine will get, all is well. B keeps the brakes and battery cooler.

 

Oh snap that was really funny thanks for that...

 

There is no VXDIAG download or cable. VXDIAG is sold as a complete ready to use module that plugs right into the OBD port and usb's to your laptop. $99 on amazon. Comes with cd. Plug & play W7-10 or XP on a burner laptop.

Make sure its the blue one that says Toyota Techstream. I have one works great. I have the mini vvci too but that sometimes does not connect happily but the VX always does.

This one:

 

Vx-Diag is really the dongle that you're buying, though it comes with a CD with drivers and some software.

It is an SAE J2534 dongle, and Toyota Techstream in principle can work with any dongle built to that standard. A Tactrix Openport 2.0 will work fine, and you might already have one of those or have heard of it, since it originated in the Subaru / Mitsubishi tuner community.

The Drew Technologies Mongoose Pro is the one Toyota actually tests with and officially supports, but it's pricier.

I would comfortably try just about any diagnosis or troubleshooting with a VxDiag or an Openport, but I might be more cautious about any actual reflashing; I'm pretty confident you'd be able to start, but less confident about getting all the way through and not getting a brick.

Actually got my brake ECU reflashed recently, and I went ahead and paid the dealer to do it; less to worry about that way.

-Chap