Red Triangle keeps coming on intermittently

Try using special applications for your Techstream for computer/+a good scanner or a special Mini-VCI
There is an error in the hybrid system and your application does not see it.
Dr.Prius can try to find the error DTC

How long ago did you change the 12V battery?
What voltage does it hold before turning on the car in the morning?

 

Hello and welcome to PriusChat!

Generally the "master warning light" (Red Triangle of Death) is triggered by a fault in the hybrid drive system. Torque is a handy app, but it is very limited and can only "talk" to a couple of the 15 or so systems in a Gen2 Prius.

You need a more capable scantool to get codes and data from all systems. Here's a thread that reviews several scantool apps and devices.
(The Autel AP200 is a good choice for "basic" diagnostics)

https://priuschat.com/index.php?posts/3290690

Posted via the PriusChat mobile app.

 

I only know of two ways to get that triangle master warning without codes:

1) use a code reader that can't actually read all the codes out of a Prius- meaning there are codes, but your reader is blind to them.
2) low oil pressure.

Low oil pressure is not the same thing as low oil level. Low level cannot trigger any alarm in a Prius- though it can lead to low pressure, and low pressure will trigger the warning triangle alarm.

Levels are read by you when you pull the dipstick.

Pressure is read by a spring-loaded pressure switch- and there could possibly be a problem with the pressure, and it could just be a lousy switch.

 

get a free 12 volt load test at many auto parts stores

 

If I'm not mistaken, gen 4 did introduce an oil level sensor and an alarm for low oil level. Older Prius gens can only detect low pressure.

 

That sounds like a very discharged and/or bad battery. The MFD test isn't all that great because turning on the car to that extent will load the battery somewhat, which drops the voltage a little on a good battery, and potentially a lot on a bad battery. It should be more like 12.5V or higher on a good battery. The 14.1V when the car is running is coming from the inverter's 12V output, which is charging the 12V battery - it tells you the car thinks the 12V needs to be charged, and even that it needs to be charged a medium amount, but that's it.

Better to get a multimeter and measure the voltage at the jump point under the hood in the morning after leaving the hood unlatched (not open, just unlatched) over night. The point being that you don't want to unlock the doors or especially open the driver's door just to pull the hood release, as it wakes up the car's computers and the load changes the battery reading (temporarily). I usually use one of the unpainted bolts on the inverter for the ground test lead. Opening the unlatched hood doesn't trigger any activity. In theory some cars might have on open hood sensor that would trigger, but I don't think that option was installed in very many cars. It isn't in mine. A cheap multimeter is around $10 (at Harbor Freight) and a much better one can be had for around $50 (not at HF, although they sell some that cost that much). The leads on the cheap multimeters are often the first thing to go, which can lead to faulty readings.

You definitely need a better OBD2 reader, there should be a code to go with that triangle, and what you have cannot retrieve it.

How old is the inverter pump? They tend to go out at 60k miles (plus or minus a lot). If yours is working poorly or not at all the inverter will overheat and the triangle will light up. At least in the summer. In the winter you could certainly drive around in a suburban environment and never know that it is out, except maybe when driving on the highway. Anyway, with the car running take the lid off the coolant tank that sits next to the inverter (the skinny one with pink fluid, on the opposite side of the inverter from the fuse box) and see if the fluid is moving. NOT the radiator cap or radiator overflow tank - opening those on a warmed up car would be a really bad idea!

 

Not bad. The first voltage values are sufficient to start the hybrid system. The third value is the norm, the voltage comes from the hybrid converter and feeds the battery.
One of the pictures shows part of the problem. Caution: The transmission lock mechanism is abnormal
Check out the thread on this error. Caution: The transmission lock mechanism is abnormal | PriusChat
But in any case, you need a scanner and a program to detect the error code.

 

Both of those cars are old enough that I imagine any (hacked) Techstream you find floating around on the Internet will support them, and certainly the current (licensed) Techstream will. Mini-VCI cables are a crap shoot, you never know who made them or what version they might be. The original manufacturer no longer sells them, so all that is out there are clones, and maybe if you are extremely lucky, an original on Ebay. Mostly the clones work, although never for the brake bleed procedure. There is also the Tactrix OpenPort 2.0 device, where you can (and should, to keep them in business) buy a unit from the original manufacturer (for around $170)

Tactrix Openport 2.0

but there are also clone devices for around $30

Mini VCI vs Openport 2.0 for Toyota Techstream | OBDII365.com Official Blog

Apparently the Tactrix devices, real and clone, all have problems accessing the TPMS.

 

A serious plea: a real Tactrix Openport 2.0 is $169 at their web store, last I checked. Any "Tactrix Openport" you find online for a low price is counterfeit. Now ...

... if you want to buy a counterfeit dongle, please consider buying a counterfeit XHorse Mini VCI or maybe some other dongle where the real maker has already been washed away by counterfeits and the damage is already done.

Tactrix is that rare maker of affordable dongles that is still around, a California business that is actually behind the products they sell, and if we can avoid buying counterfeits of their dongle, we can keep it that way. I don't work for them, I just think it really is to our advantage to have a company still actively behind their product, at a cheaper price point than the Opus / DrewTech Mongoose.

 

All of that was true.

What is also true is that the Feds are long overdue in mandating a universal diagnostic port for all cars sold in the USA which is accessed through a simple USB port, with a read (most of it) and write (some of it) interface. Because cars that don't have emissions systems don't have to have any sort of standard diagnostic port (although most do) and you know that will be abused. For instance, this could be similar to the /proc or /sys file systems on linux. Especially since cars are turning into rolling computers anyway. Moreover, the little box that provides this interface for any vehicle would have to be easy to access (for instance, just under the dash, no disassembly other than a couple of screws/bolts and one connector to the car, one to the port), and limited in cost to $100 (inflation adjusted). All specifications would have to be public, so that others could make them. Hidden files would be prohibited. Allowance would be made for write locking certain security related files, otherwise, no write locking. All firmware upgrades for this interface device would have to be free and installable through the USB interface. A procedure to load firmware must exist that does not require the previous installation of software. (The device could be "unbricked" by the end user even if a firmware update went awry.) Lastly, the manufacturer would only be allowed to have a single type of such box for all models in any given model year, with the only exception being the use of such a device from another manufacturer, either just using their tech, or reselling their car under a different badge.

The idea of course is to remove all the rent seeking which is currently built into the automobile diagnostic market, which plays a significant part in increasing repair costs.

 

You've got nothing to lose by trying. The only thing I didn't like about what he did was that he took the power from the unfused side. If I was doing this, I would take the wire from the fused side.

If that does fix the problem, I would make a permanent bypass on the underside of the fuse box so that it doesn't look so hinky.

 

The 12V DC from the 23V battery/Inverter goes into the front fuse box on a big copper cable that terminates under the red cover at the jump point. From there it is distributed to one side of each fuse position. At the other side of the fuse position a circuit goes elsewhere in the car. When the fuse is inserted into that slot that circuit is active and protected - if too much current is drawn, because of a short or component failure or the like, the fuse will blow. This is to protect the car from damage, and conceivably, fire. In the video you cited the power is tapped from before the fuse. If that wire was to fray and touch a ground a very large current would flow through it. There is one last fuse at the battery, but it is 100A, so that wire would certainly get hot enough to burn off the insulation and possibly start a fire. It might even blow that 100A fuse, which is going to render the vehicle completely inoperable, and isn't going to be cheap to replace. What dolj is saying is that the wire should have been tapped in after the fuse. Then if the wire shorted to ground it would just blow that relatively small fuse, and it could only affect that one circuit. Wires often short to ground because pretty much all of the metal structural parts of the car are electrically connected and are at ground potential, and wires tend to rub on those parts of the car and occasionally the insulation wears off and the metal conductor shorts to them.