Confirmation of TPMS light status

Hi,
I had one TPMS sensor on my '06 Tundra replaced because of a broken stem and the tire couldn't hold air, and then drove for 2 months with a BLINKING TPMS light on my dash until I had the other 3 sensors replaced on the running tires. Tire guy informs me that the spare sensor is dead also. I fully expected to continue to see a flashing light, but now it's SOLID. I checked all the tires and the pressure is fine. The tire guy is trying to tell me this solid indicator is because of the dead sensor in the spare, but I'm fairly certain he is wrong, and that it should be blinking instead. I'd prefer it blinking; the solid "false positive" light is really annoying. Any ideas besides taking it to Toyota, which I'd prefer not to do? Thanks!

 

The only way to really know what's going on is to attach a code reader/app that lets you tap into the ECU for the TPMS to see what codes are set, and why it's bitching. Your mechanic should have such a tool. I bought my own tool to do it.

As with most things electronic on these trucks, you want to stick with OEM brand (Toyota/Denso/Aisin). I'm assuming the tire shop probably used generic/3rd party sensors. That may be at the root of the problem.

But really, the next step for you would be to check what TPMS code is set - which again - is not something your average $30 code reader can do.

 

I replaced all sensors on mine with Denso. The truck does in fact have - sensor in the spare tire.

5 sensors total

 

Just confirming - mine was same also - sensor in the spare. I used the www.densoautoparts.com website to look up the replacement sensors. Note, they usually have at least 2 part numbers: 1 for steel wheels, 1 for alloy wheels.

 

I went with these -

$38 Denso 550-0103 TPMS 315-MHZ Sensor for Toyota/Lexus with Factory Alloy Wheel Options. (THIS SENSOR MUST BE PROGRAMMED BEFORE USE), Black

Denso 550-0103 TPMS.

I took mine to a tire shop and were able to see what sensor wasn’t communicating with their little machine.

Just have them check your spare tire. Try a different shop or a more commercial shop for that service. Same machine is used to program them all.

 

It's worth mentioning, some wireless OBDII dongles, when paired with smartphone software, **CAN** dig in on TPMS problems.

Here's how I resolved mine: https://www.tundras.com/threads/obd-thread-pids-apps-dashboards.60459/page-10#post-3132384

Here's more info on the product I bought - they do have a cheaper product; I opted for the MX+ because of the unlimited support and add-ons, which has helped pay for itself: https://www.tundras.com/threads/1st-gen-lunch-table-general-discussion.60450/page-1640#post-3264002

 

But can anyone confirm that with a dead sensor in the spare, that the light on the dash should be blinking, as opposed to steady?

 

It's my understanding, generically speaking, across multiple manufacturers:

Solid light = Low tire pressure
Flashing light = Failure to communicate​

You have three basic components to the TPMS system:

• TPMS ECU (actual brains of the operation)
• TPMS receiver (mounted in roof between dome light and 3rd brake light, hardwired to ECU, catches wireless signal from sensors and sends to ECU)
• TPMS sensors (in each wheel, broadcasts tire pressure signals indiscriminately from tire)

"Failure to communicate" can be any number of things. TPMS receiver died. Wiring fault between receiver and ECU. One or more TPMS sensors aren't transmitting (battery dead or physical damage).

All 5 of my tires have sensors from the factory. You can tell when you look at the valve stem whether or not it's a standard black valve stem or if it has a TPMS sensor, they're silver/alloy colored.

When I open my TPMS network to debug, I see five tires programmed in. If you're on your original TPMS sensors, yes, it's quite possible that (A) like the other sensors, your spare tire's sensor is dead and (B) that sensor failure is causing the dash light to flash.

In my case, I have more than 1 sensor failed. I had options:

1. Ignore the flashing light
2. Use a tool like Techstream to erase the failed sensor from the ECU so it no longer expects input from that sensor (no sensor to monitor = "no problem")
3. Use a tool like OBDLink to erase the error code for that sensor out
4. Replace the bad sensor(s)

I personally opted for #3, knowing my truck is 17 years old and on its original sensors, and I'd be updating my wheels & tires soon, at which time I'll be doing #4 anyway.

You have now pretty much exhausted my knowledge of TPMS. But if you still have questions, fire away, maybe someone else can pitch in.

 

Since his is ON, it should indicate low
pressure, as you mentioned with your “genetically” comment and matches what @jerryallday said.

from 2006 Owners Manual…



I suppose it’s easy for me to say, since I don’t have TPMS but personally I’d check air pressure in spare and go from there