DISAPPOINTMENT

How do you start your Prius Prime from iPhone inside the house? Some folks can see tire pressure from the Toyota app on their phones.

 

Have you checked your Toyota App to see if it displays the TPMS data? I don't have Toyota App installed on my phone. In fact, I "opt-out" from the connected service, so I can't check it. But see the thread below for Gen4. The same thing applies to PP. Some trims do have the ability to display the TPMS data. Please note that even if it does display TPMS data unless you have adjusted the TPMS sensor registration, the diagram showing the location of the tire does not often correspond to the sensor data displayed. Every time you or the dealer rotate the tire and wheel, the location changes, but the car's ECU does not follow the location.

Did they remove ability to see tire pressure from app?

If the app does not work, then the easiest and cheapest way to see the individual tire pressure is to use a separate stand-alone external TPMS. They are cheap, about $30-50 for a kit. It works. I had it on my PP for a while. The problem is that external sensors are prone to damage due to road hazards and salt corrosion. They didn't last very long for me. Once one sensor is out of order, then you have to replace the entire kit. There is no way to re-program just a sensor for most of those cheap kits.


You can also use the OBDII dongle and APP. Tire Assistant for Android phones will work with almost any OBD ELM327 Bluetooth dongle, even on cheap $10 ones from Amazon. I think the Torque App or Carista also has the ability to pull the TPMS PID. However, most OBDII apps will not see the live TPMS data while driving. The car must be parked for it to work for safety reasons. This restriction also applies to TechStream connected via OBDII. The only one I know that keeps a display of the TPMS data during the drive is one by Scan Gauge II. The thing is that PID is not standard, so you have to do some X-gauge programming to make the unit display 4 TPMS data values on the unit, and the unit must be connected to the OBD2 port all the time.


Moor useful tools would be to have a TPMS handtool like Autel MaxiTPMS tool as shown below. I have a TS508. It is a bit expensive, but it has the ability to trigger, read, program, and re-register the TPMS sensors for almost any vehicle. A similar but cheaper TS408 would also work for just reading TPMS sensor data, but it lacks an OBD2 interface and thus does not work for Toyota and many other Japanese cars that require an OBD2 connection during the TPMS sensor re-learning process. If you have two sets of wheels for summer and winter with separate (uncloned) sets of TPMS sensors, then TS508 will pay itself back in a few years by not needing to go to a dealer or tire shop to register the TPMS sensors. I have three Japanese cars that require an OBD2 connection for registering TPMS sensors. With two tire changes in spring and fall, the cost would be at least $100 a vehicle every year if I took them to a shop to swap the wheels and register the TPMS sensors. So, I know the unit has paid itself even though it was over $200 initial cost. BTW, the TPMS tool like TS508 also does not work while the car is in motion. So, you can not get the live feed of TPMS data while driving.

 

That's the one we use at work. Pretty slow for reading pressures, but just the ticket for finding the one with a dead battery.

Edit to add:
It was easy to find my low tire this morning. It was the one making the odd noise due to a screw clicking on the pavement at highway speed.

 

"I can start the car with my IPhone inside the house"

i have been able to do this since my 2004, can't you?

 

I use those pressure color indicators that screw onto the valve stem. They're not really that accurate; but they work.

 

Yep, your good for a year. I decided to not pay the annual/month fee - didn't have any use for it and the software was buggy...

 

Isn't that one of the Prime trim level idiosyncrasies where only the base (LE) model had APP features not available on the upper trim models?

 

Neat trick, for a phone that wasn't introduced until summer 2007.

Maybe you were leaving some other phone in your house as you went to start the car?

 

Just remember that the tire location and psi showing on the screen may not match. As I said, ECU cannot tell the location of the sensors. It only knows the ID, battery level, temp, and Psi.

You can check which sensor corresponds to which tire on the diagram by deflating one at a time and checking which one has lower Psi. But every time you rotate tires or buy new tires, the location will change and you must repeat. OR ask the dealer to re-learn the TPMS sensor into the ECU slot in order that will match the display (not hard, but requires a special TMPS tool or Techstrem).

 

well, it was tongue in cheek, but you can start any car with a phone inside the house...

 

Thanks you! I wished I had gotten one of these earlier. I'm going to get one now!

 

Just curious, what are you going to get? External TPMS, OBDII dongle with an app, or TPMS tool?

 

The l MaxiTPMS tool, TS508. I wonder if the ones on eBay are legit.

I lost a good tire this last summer because every winter we drive around with the TPMS light on because I don't have a way of changing the sensor ID's. So we got used to the light, but with the summer tires one got a nail and I didn't notice the yellow light like I should have, and well, ran the tire flat and now I have a different tire than the other 3, which isn't ideal. I don't want that to happen again.

 

Can't say all are legit, but I got mine from eBay and it works.

Yeah, I had my winter set of wheels without TPMS sensors for a while. It was cheaper to buy tires and wheels as all set without TPMS sensors from an online shop. They included the installation of the tires and balancing in the price, so I did not install the TPMS sensors when I got them. I used the external TPMS sensors as shown in my comment above, but that did not last long. Last winter, I bit the bullet and paid a shop to install cloned TPMS sensors in all 4 tires. I wanted to wait until I had to purchase a new set of winter tires. They were 5 years old tires but still with plenty of treads left on them. The TS508 kit I purchased came with 8 programmable Autel MaxiOne TPMS sensors, so I did not have to buy a new set of sensors. I just had to pay the shop for dismounting the tires and installing the sensors and remounting/balancing all of which ended up costing close to $100 which is the same cost as for new tire installation. Unless you already have TPMS sensors in your winter tires, you will have to pay for the sensors and installation, even if you buy a TS508.

You can use TS508 to program their MaxiOne TPMS sensors. Once you clone the sensor IDs from summer tires, then you don't have to do the re-learn procedure when you swap the winter wheels. The same IDs are already registered in the ECU. This made the winter tire changeover even easier.

Read more on how to use TS508 in this thread:
How to Use the TS508 to Relearn TPMS Sensors?

 

They also leak, and if they're plastic they are prone to deteriorate in UV light, crack and THEN leak.
BTDT.

Make sure you know how to deal with a flat tire, and if you're one of those unfortunate 'future victims' that have a 'doughnut' instead of a proper full sized spare tire then you may want to consider AAA and verify that you have a backup plan in areas where there is not a very good cellular signal.

 

I must've been very lucky. Sheared a few heads, off of them on the right side of the car - too close to the curb; but haven't had one leak on me. I thought one of them was leaking once, but eventually found the nail in the tire. The nail head was gone, just the stem of the nail. It didn't help that the city just repaved the roads in my area; so it was pretty well hidden.

 

Unfortunately, the latest version of the Toyota app does not display the tire pressures for the Prius Prime, and my subscription for the Toyota Connected Services is active.

However, I was pleased that it now displays the battery percentage. There is something peculiar about it though. The shown percentage is quite a bit higher than the EV SOC shown on MFD. @Salamander_King, do you think that the app is showing the SOC for the whole battery, including the hybrid reserve?

 

I don't have Connected Service on my PP thus I can't use the Toyota App. So, I can't check it on mine. But... if your App is showing 51% and it is way off from the MFD SoC, then it is not likely because it is showing the absolute SOC of the traction battery.

The reason is as follows. The MID SoC level and the absolute SoC level (reported by Hybrid Assistant) are perfectly linear relationships between MID 0-100% corresponding to HA 14-84%. Using the colinear points to generate a graph, this linear function can be written as
y=(100/70)x-20.

So, for the Absolute SoC (x)=51 in =(100/70)*(x)-20 function,
the MID SoC =1.42857*51-20=52.86

Basically, it means the MID and Absolute SOC at half point are very close. If anything, at absolute SoC 51%, the MID SoC should show a higher number not lower.

You can just check to see what SoC the app shows when the MID is displaying 100% (fully charged) and when it reaches fresh -- (0% or EV range freshly depleted). If that number is not close to 84% and 14% respectively, then it is not showing the absolute SoC, and I have no idea what that number represents.