Can't reset tire sensor

It can be costly to replace TPMS sensors.
My tire place would charge me $30/tire, and that is just the installation fee assuming I buy the replacement TPMS unit (from Amazon) and reset the codes by myself with Techstream.

TPMS Management with Techstream | PriusChat

 

I had a friend that bought a 2006 with 2 failed sensors, I used techstream and disabled all 4, no more lights

 

How long did that last? My experience is the warning light will come back on, although I never tried disabling all 4 tires.
How did you "disable"?

I can get the warning light to go out for weeks, but at some point (after a long enough drive) the computer will figure out you faked it out.

 

I registered 4 new codes.

0000001
0000002
0000003
0000004

All cleared.

I took a screen shot of the sensor codes before I changed them, just in case I have to put them back. So far after 3 weeks, no warnings. Just like my 05 without sensors

 

If that's true, that's cool as no one has yet figured how to disable the TPMS like that. But I am skeptical. I have tried similar to that approach and seen it to be temporary (several weeks) success.
If the person only does short drives, then it could take a while for the TPMS system to realize the spoof attempt.

 

Try it, it works perfectly. I just did it as an experiment after reading your 0000001 code, just did it 4 times

 

I will try but my Techstream sessions are not too frequent as I use a desktop.
Tell you what, when I finally lose another TPMS ( so far still have 3 of 4 good almost 11 years old) I will def try it then.

 

It's only been 3 weeks, I can update you if the lights return. But my friend does really short trips everyday, less than 10 miles 1 way daily

 

Does a warning light get either of you pulled off the road, fails inspection?

 

I'm not sure if it'll fail inspection. CA has smog inspections and this is not emissions related

 

In my experience, it can take 20 minutes of driving for the system to quit looking for a dead sensor and throw a light. Interesting observation - please keep us updated.

Inspection issue depends on your state. Here is a list from TireRack
Wheel Tech Information - State TPMS Regulations

 

That's very interesting re: state regulations!

Sure glad my state VA is on the correct side of that. I am thinking many states do not even have inspections, so to require TPMS to be working is a real hassle, for those subjected to states mandating working TPMS.

 

The other day someone assured me that I'm nuts, and that there is no sensor in the spare. Be that as it may, I dug out the spare, found it at 25 PSI, filled it to 60 PSI, and was suddenly able to reset. So either the conventional wisdom regarding a sensor in the spare is wrong, or I experienced The Mother of All Coincidences. Can't hurt to check, anyhow -- glad I didn't NEED my spare, only to find it deflated.

 

The ECU can handle it (it has a 5th data set, visible in Techstream), but a sensor usually is not installed in the compact spare they provide in our market. Glad that worked for you.

Always worth keeping that spare ready, in any case, should you need it!

 

@KJ Fitz , what does the valve stem on the spare look like, metal or black rubber? Metal would likely mean it has tpms sensor, and black rubber definitely not.

 

One of our PriusChat members (I think @RobH) added TPMS to the spare tire to make 5 tires covered, but it required that he manually reprogram the ECU to set it for 5 tires. other wise the system only takes 4 tires and will not let you insert the code for Tire5.

 

The TPMS ECU does in fact support 5 tires. About 7 years ago I was studying the messages that Techstream used to query/set TPMS status. There is a message (0x21 0x06) that queries the number of TPMS sensors that are registered. I discovered that Techstream reported 4 or 5 sensors, depending on the reply to the 21 06 query. I tried a leap of faith experiment of sending a message that set the current value to 5. It worked, and I was able to register my spare as a TPMS device. The program that did it was a one-off experiment that is lost to history. Note that the messages are for the K line, not CAN. It will be necessary to directly access the Techstream device driver to send these messages - CAN bus and the ELM don't have the ability. The protocol allows any value of 0 to 7 to be set, although only 5 has been tested. Note also that some Toyota vehicles have a switch that selects between two sets of TPMS devices. The Prius ECU is wired to report the switch in the Main position. Perhaps comparison of the Prius ECU with an ECU used in a two-set vehicle would reveal how to add a similar switch to the Prius.

The following are the messages I decoded. The values are in hexadecimal.

82 2A F0 21 06 ........ Query # sensors registered
84 F0 2A 61 06 x0 y0 .. x=main set, y=2nd set
....................... x:8= 4 sensors, x:A= 5 sensors (high 3 bits of Each byte)

84 2a f0 3b 06 x0 y0 .. Set # sensors that can be registered.
....................... x=main set, y=2nd set
....................... x:8= 4 sensors, x:A= 5 sensors (high 3 bits of Each byte)
82 f0 2a 7b 06 ........ Reply

82 2A F0 21 07 ........ Query # of sensors registered (during registration)
84 F0 2A 61 07 0x 00 .. high 3 bits of x is count

82 2A F0 21 09 ........ Select Switch position
84 F0 2A 61 09 x0 00 .. x:0=Main, x:8=2nd

 

After a long saga to figure out what was going on. I ordered the same MVCI cable on Amazon and tested it out. Guess what IT WORKS! I can read my TPMS sensors. Whohoo! So after paying $60 for a cable on eBay thinking it was the latest version 2.0.4 firmware. And going back and forth having installation problems. They sent me another cable and it worked for all my cars, but no TPMS readings. So for $60 I got a 90% working cable and customer support that made TS ver12 work. The Amazon cable is firmware 1.4.1. Finally I can replace my TPMS sensor. Does anyone know the orienation of the sensors? Is sensor 1 driver front, sensor 2 pass front, sensor 3 pass rear and sensor 4 driver rear? Thanks for all the help everyone.

 

Glad this cable is working as expected. The sensors are not in specific locations; is it clear that one is not reporting? You need to watch the numbers and drop each tire in turn by a few psi to figure out which working sensor is in which wheel/position. Then you will know where the one is that needs to be replaced.