Tools for diagnosing Generation 2 ?

Don't let Autozone clear the error codes. Read them, yes. But don't clear them in case you end up going to Toyota service for a proper and $$ diagnostic. My first guess would be to check the 12V battery.

 

Mini VCI is the best diagnostic SW. Buy a Windows XP or Windows 7, 32 bit OS laptop to support it.

 

Yep, $20 or so for the Mini VCI and $75 or so for a decent old laptop on Craiglist got my garage set up for the Gen 2. Bite the bullet and get one MS product. Or ask around, as lots of folks have these as doorstops.

Mini VCI is not extremely robust, and has no documentation, but when it works and you can figure out the menus, it's very powerful.

How old is the 12V, and what's the voltage at the battery or jump terminal after resting overnight? Then check in IG-ON, then Ready. If much under 12.2 V, the battery is getting old. If under 12, that's probably your problem--hope so.

Ditto the above for a quick check at Autozone. They normally don't clear codes, and don't let them. If you get a replace hybrid battery code, contact Toyota for a goodwill contribution. You're very close to the warranty expiration and some have had some luck with this. You sound like a busy guy and replacing modules may eat up more of your time than you like over the next couple of years.

 

Somehow, a lot of the early-2000s Prius FUD lingers on in the ubiquitous assumption that "the worst" is going to have something to do with the battery. Out of various possible expensive Prius component failures, the battery is one of the easier to deal with. Meanwhile, the lights on your dash (your only information so far) stand in for literally hundreds of trouble codes for different problems ranging from serious to trivial. Just relax and get the codes read.

They'll have to be read by a Prius-aware tool (such as Techstream) to get the hybrid-warning-light ones. Generic tools should pick up the engine codes, and might pick up the brake codes. There's also a toolless way to get the brake codes, but a scantool is easier.

-Chap

 

I agree the Mini Vci is a good tool to have and the price is OK considering it runs on pirated software.

A quick test you could perform ( all the tools are on hand ), is on the Inverter Coolant Pump also known by Toyota as the 'Hybrid Electric Water Pump' to see if it has died of natural causes. The part box says " G9020-47031" "PUMP ASSY, WATER W/M" for a part dated 02/0217
Let the car cool down a bit, remove grille top cover, make 'Ready', wait for the ICE to shut down and check for turbulence in the air separator/tank.
Locate the Pump and reach down and touch it, if you can there should be a small amount of vibration felt and hear a hum in the drivers seat when the ICE is off.

There was a recall in 2013 to change out the pumps in Gen2 2004-2007 and could have been extended to go all the way to 2009 as they all were identified as failing early. The dealer may do this for free if you have not done so during the recall but will not a second time.

You may want to do a search.

 

this was my answer to another post, but use it if it works for you

sounds like Batt but another issue that lights up the lights is Brake Actuator which is extended on coverage. Can't recall if 2004 has the actuator issue.
https://priuschat.com/posts/2353425/

You can always try to ask Toyota USA for Goodwill warranty assist on Battery, chances iffy but we've been surprised before and NJ is CARB so sometime CARB states get more favor.
https://priuschat.com/posts/2507664/

 

You may want to confirm that the 'Inverter pump' is working now by looking for eddies in the separator/tank as the replacement Inverter. Replaced pumps have been reported to fail with the owners having to pay for replacement of the recall replacement.
If there is no eddies in tank the fuse could be blown. The fuse can be blown by the pump failing to a shorted condition.

 

The 12 needs to be replaced and that may solve all your problems. 11.8 V on an AGM battery is essentially discharged. The 14 V in Ready means the charging circuit is working just fine.

Current codes will reset when the offending parameter is fixed. Some codes require a "drive cycle" to be completed, and I'm not sure what that is on the Prius. Some cars are pretty involved, and may take a few trips at different speeds.

 

It's good news Autozone didn't find codes. They usually can get the big ones like hybrid failures. What you may have is probably a load of low voltage concerns on various ECUs.

 

If you register on the Toyota owners Web site, you can see what, if any, recalls have been performed, including the inverter.

Personally, I would check the 12-volt after the car has sat for 8-12 hours, Use a multimeter at the jump points under the hood.

 

Disconnecting the 12v battery resets many of the codes (not all). Real failures will then return as you drive. Try another reset after you charge the 12v and see if the codes return again.

JeffD

 

I'm sorry you had to go through that; you've posted (another!) example of the real costs, both in money and lost time, of this persistent PriusChat notion that any codes no one has bothered to read or diagnose probably mean you need a new 12 volt. (The voltages you posted earlier were perfectly fine, considering what the MFD sees is a good fraction of a volt lower than right at the battery, and it's expected to drop under load.) So you spend the money on a battery, and take the time to put it in, and feel the temporary relief at the lights being off (since changing the battery wiped memories), and only when they come back on can you get back to solving the problems.

Anyway, it's just time to get back to real diagnosis and get the codes read. This thread has already mentioned two of the possible causes for those lights to come on. That only leaves about 698 more, which the codes will immediately whittle down for you to a small likely set.

Techstream is the best way to be sure of getting the codes from all of the ECUs capable of reporting them. If you're waiting on a Mini VCI and looking for something to do, you should be able to get the blink code versions from the brake ECU just using a wire (see many other threads for details). (Sometimes, the code in the brake ECU will just be the C1259 saying another ECU informed the brake ECU of a problem; in that case, it doesn't tell you much until you hear from that other ECU.)

-Chap

 

Personally, it sure sounded like 12-volt problem. But I would never replace without checking the actual voltage after a several hour resting period. And, I would not rely on the MFD. Only real way to do it is on the actual battery or at the jump point under the hood....

Having said that, his battery was five years old....

 

Considering the car is still driving, sounds like very early stage of hybrid battery failure. The car I have right now went through very similar symptoms last month with the previous owner. It will be drivable, but will get worse and worse as the days go by. Mine is a 2007 Touring with 140k miles. I installed Gen 3 modules (all tested >6000mah) in the 2007 case and right now I'm still on my first tank of gas. 285 miles and still have 4 dots on gauge. Averaging 49.3 on the MFD. 23 miles each way to work, 5 day a week. 3 minutes of 25 mph zones, 10 minutes of 40-45 zones to get to highway, about 14 minutes of 55-65 mph highway and then about 2 minutes of 35 mph zones. Of course, I'm just like everyone else and go "hammer down" mode on the highway

Looked at my data sheet and needed to make some corrections. Guess my memory isn't what it used to be. The original battery modules are being tested right now. Initial voltage checks showed one cell around 6.3v, one at 6.1v, one at 7.0v and the remainder at ~7.55 to 7.76v So far all modules have cycled and tested >6000mah, except the one that was 6.3v. It was cycled 5 times and capacity maxed out at 2013mah. Although the 6.1 and 7.0 modules recovered to 6300+ and 6000+ mah, I suspect they have some significant self discharge rates and will be monitored long term for further testing.

Maybe you'll be lucky and have a similar problem. Easy to fix. If it is the battery, and you're bored and want to come to Columbia, I'd be happy to help you out.