Tire pressure

I wouldn't trust the dealer on this. That's not what my car looks like. They probably have the tires slightly under-inflated for comfort (soft ride), but this lowers tire life and your MPGs considerably. Also causes the tires to heat up on long rides, that's the root cause for the blow-outs on the Ford Escape/Goodyear problem several years ago.

It's not that hard to check it yourself, just need a tire pressure gauge that you can get at Target or a gas station or anywhere for probably $5, and in 30 seconds you can know for yourself what the pressure is.

 

Hello Prius42,

Just a quick note on the info you posted about the Data Stream available through the OBD connector, all of those parameters are viewable from the TPWS ECU. Unfortunately, I am unaware of any aftermarket systems for recovering this data.
At the dealership, we use the Toyota TechStream, which is a PC based scantool. It is essentially a Panasonic Toughbook mounted on a "backpack" framework made by SnapOn which houses the Vehicle Interface Module and provides recharging for the PC and has the interface cable which connects to the OBD II connector under the dash. This system connects wirelessly to the dealership's internet access and allows for immediate access to TIS (Toyota Information Systems - for TSBs, repair manuals, wiring manuals, etc.) and access to Toyota Technical Assistance.
We also now have TechStream Lite, which is basically the software downloaded onto a technician's personal laptop and the Mongoose cable which connects the laptop to the OBD II via a USB port. It then provides pretty much full capabilities of a TechStream, but must connect to the dealership internet at regular intervals in order to remain functioning. Both of these can access all the parameters you listed, but are obviously based on a device the size of a laptop.

If there are other devices which can interface with all the ECUs in Prius, I am unaware of them, although I have not researched availability of other devices, since the TechStream Lite serves my needs.

 

The TechStream software looks pretty complete but the $1400 initial cost and the $1100/year subscription is a bit much for casual use.

https://techinfo.toyota.com/techInf...hinfo/html/prelogin/docs/tsliteflyertinfo.pdf

The 3rd party DynoScan software from Auterra seems to capture most of the same functionality and I found a few others. I'm sure they aren't as complete as the TechStream stuff, but they are cheaper. Either way, though, it isn't a real solution for casual reading of the TPMS system. I'm still hoping for something more like the scangauge, but until then I'll probably take your advice and use a pressure gauge pressed on the Schrader valve... Seems a pity...

 

$1400? Ummmmmm.... Actually, the initial cost for a full TechStream (Toughbook with Snapon Backpack and charging station) was $6500. I had originally planned to purchase one myself, (I have a slight insanity about spending money on tools) until I found out about the $1000 - $1100 per year to keep the system updated and active. The TechStream Lite, however is actually affordable for techs, costing us $450 for the Mongoose cable. The software is then downloaded from TIS, leaving the tech responsible only for his/her own laptop AND having the dealership IT person connect it to the dealership intranet. The TS Lite MUST ping the official dealership website successfully at various intervals in order for it to continue to function, thereby preventing use by outside shops. BTW the Mongoose cable is the ONLY cable which can work with TS Lite.

 

Whoops! Just looked at the flyer you linked to! I guess they now have S Lite avail to outside as well... Still pretty pricey! I'm glad they don't charge the techs fro access to TIS even for our TS Lites. One of the few perks of being a MDT is having home access to TIS.

 

Buying tools is actually an insanity I understand! Someday I might work myself up to the techstream lite package but it will have to become a prime hobby to do that. I do think it is a nice benefit that you have home access to the full toyota diagnostic software. Since you have it, do you see the tpms readouts? Can you screendump an example showing the tire pressure and temperatures for all four tires? There probably isn't yet a viable solution for a simple scangauge like readout, but at least you will have shown that the information is, in principle, available. Thanks!

 

I am out of work for a few more weeks, recovering from rotator cuff surgery, but as soon as I get back to the shop, I will see if I can figure out how to do a screen capture and post it. Simple solution, I can simply do a print of the live data list and then scan it in. The screen capture is easy to do, but comes up in a format designed for TIS so that the data can be sent to tech assist if necessary.

 

BTW the latest version of TechStream software has the TPWS sensor pressures listed on the Health Check screen. Health check is a one click screen that pulls up the status and diagnostic trouble codes for all ECUs supported on that particular vehicle.

 

Excellent! I'm looking forward to it. Thanks!