Stupid tire pressure sensor light!

Does the spare tire have a TPMS sensor, and is it filled with air???
All 4 tires have the same pressure???
Did a TPMS sensor on the snow tires go bad?
Do you even have TPMS sensors on the snow tires???
You said you pushed the set switch and no luck...
I am just throwing out thoughts here.....
Lets see what else????

Anybody else, jump right on in here...

 

As the Magliozzi brothers from Car Talk have joked in the past you can get a cheap warning light removal kit at any hardware store like Lowes.

All joking aside - if this happened just when you had your tires switched over to snows could one of the sensors have been damaged - from what I understand they are somewhat fragile.

 

Assuming that you have correctly done the reset procedure, it means that the tire shop damaged one of your sensors.

Tom

 

I've had this problem since I purchased my Prius in April. They keep telling me the tire pressure is low, or too high, or 'not quite right' - but the light blinks for sixty seconds, then stays solid. It sometimes goes out by itself, but then comes on again; its all intermittent. I've taken it to two Toyota dealerships who refuse to consider it anything beyond 'driver error'.

 

Did they check the pairing with the TPMS sensors?

Tom

 

Did they put the snow tires on the same wheels as your original ones? Is it a separate set of wheels & tires w/ their own TPMS in them or no TPMS on them?

The light blinking for 60 seconds and staying solid on is a sign of a "malfunction" with the TPMS. Granted, malfunction can mean a variety of different things. Need a little more detail in regards to putting the winter tires on.

 

have they hooked it up to techstream at the dealer? If that light blinks then stays solid, it should be logging a DTC within the TPMS ECU. Even if the light goes out, it should log a "history" DTC until it is cleared using techstream. If you take it there next time the light comes on, tell them you want the printout of what techstream says is/was the problem. You could just have a battery slowly going bad in the TPMS in a wheel and that's causing it to not receive the signal consistently, but that's purely speculation on my part.

 

No, the first dealership I took it to (Burnsville Toyota - Burnsville, MN) said that it's a tire pressure problem, too high if I remember right, they deflated the tire to the 'correct' pressure and sent me on my way - I had to talk them out of charging me as they said my car I purchased wasn't NEW therefor wasn't covered under warranty (it was purchased, but returned by the person 24 hours after purchase - never titled). The dealership I purchased the vehicle from (Walser Toyota - Bloomington, MN) said it was a common problem with using ordinary air, and tried to upsell me on filling the tires with nitrogen.

Neither time was using the techstream tool offered, and the last time I had the vehicle serviced - they refused, mentioning it was a 'tire pressure problem' and that there was no problem with the vehicle as sold.

 

Holy smokes. WOW, that dealership scares me!

1 - I don't believe the TPMS will trigger the light if the pressure is too high, only if it reaches too low.
2 - If it wasn't titled by the first person, that's a NEW car (at least here, that's true). Not to mention, it's still covered under the 3/36 manufacture warranty, even if you were the 2nd owner of the car.
3 - Next time, tell them you want to know what the manual pressure reading (using a pressure tool) says and what the TPMS are registering. Maybe you've got a fault sensor registering an incorrect pressure, by chance.
4 - Find a new dealer! Ok, this should be item 1, really.

I'd write a letter to the manager at the dealership or at least try to talk to him/her on the phone. Tell them your issue, that you've been there more than once and the problem continues to arise. If that doesn't work, contact the regional toyota people. Keep moving up the chain to Toyota Care if you have to.

 

The TPMS system in the car is set up for 4 sensors in the wheels. When you change over to winter tires, you have 4 options.

1. Mount the winter tires on the original wheels, keeping the same TPMS sensors.

2. Move the TPMS sensors from the old wheels to the new wheels.

3. Use different wheels, tires, and TPMS sensors.

4. Use different wheels and tires without TPMS sensors.

Choice 4 will result in the TPMS warning light being ON whenever you are out of range from the original sensors. If you store the original tires (with sensors) near where the car is parked, then they will be detected and the light will go out. A few miles down the road, the system will give up on waiting for a signal from those sensors and turn on the warning.

Choice 3 requires that the sensors in the winter tires be registered with the car. This can only be done with the Techstream scantool, or with some high end TPMS service tools that not all tire dealers have available. Pressing the RESET switch in a Toyota does not cause the car to register a different set of sensors. All the RESET switch does is to establish the tire pressure warning level at about 75% of the current pressure in each tire. If the TPMS system in the car is not updated with a service tool, then it will behave the same as choice 4.

Choices 1 & 2 save the cost of a 2nd set of wheels, but those savings will be quickly eaten away by all the mounting/demounting costs.

The TPMS sensors can be damaged when a tire is mounted/dismounted. The people who mount/dismount tires should be experienced enough by now that it shouldn't happen, but the sensors are still fragile enough that it could happen.

The only way to diagnose a TPMS warning light problem is to attach a Techstream (or similar) scantool to the diagnostic port in the car and read out the status of the system. The scantool can identify which tire(s) has the problem, and what that problem is. When everything is properly set up on the car, the warning light signals that at least one of the tires is at or below the warning level pressure. If the sensors are not properly registered, the light will also signal that the registered sensors have not been found.

Mechanics who work with other vehicles may confuse the Prius procedures with those in other vehicles. Some Toyota/Lexus vehicles have a sensor in the spare tire (the Prius does not). Some Lexus vehicles have a switch in the glove box for selecting between two sets of sensors. The TPMS system on some non-Toyota vehicles can learn a new set of sensors without having to plug in a scantool.

It is important to record the serial numbers of all of the TPMS sensors. The only official Toyota way to read the serial numbers off a sensor is visually, as in demount the tire and look. There are tire dealer tools that can electronically read those numbers, but your Toyota dealer may not have that tool.

I recommend that people who have separate summer/winter wheels get a written record of the TPMS sensor serial numbers. The numbers are required to register a different set of sensors.

 

Another way to deal with scenario 3 is to get your own TPMS setting tool - like this one: ATEQ TPMS Quicket Device | Revolution Supply Co. .

It can read your current TPMS sensors from the ECU, and with a PC application can learn a second set of 4 sensors and load them to the ECU when you switch wheels/tires. I have one and just did the summer/winter switchover and my new sensors were programmed very easily. It costs less than having the dealer do the reprogramming assuming you use it twice a year and plan to keep the car for more than 1 year.

 

I have had a conversation with the service manager at my purchase dealership - he mentioned that I should bee-line it over to them when the light comes on, never shut the car down - that way, they can check the onboard log to see what's going on. I've tried that, and the technician shut the car down, restarted, the light went away - so they wrote it up as fixed. So they won't field the complaint. As for Burnsville Toyota, I will never set foot into the place ever again - that problem fixed.

Would something that reads OBDII codes from the interface, logging them in relation to time, place, and operation conditions (ie - Torque for the Android phone) help my case?

 

You need to find a real dealership. This is not rocket science; they should be able to easily help you with this.

Tom

 

I hope that you don't forget to report this service manager to Toyota.......he's bad for Toyota.....he's bad for you. !!!!!!!!!

 

With my 08, I had two problems in the first 8000 miles- both turned out to be nails and slow leaks. The next two times by 18000 miles- no problem was found. The last 18000 miles- no TPS light. I think what helped was that I checked the pressure following my 5K visits to the dealer. When the light comes on at 32 psi, and the dealer leaves them at 33 psi... well problem solved for me.

 

Even if they shut if off and the light goes away, something triggered that light. If it isn't the pressure being low in a tire, it will still log a DTC. Shame on the service manager for not knowing this or actually hooking it up to try to find out if it had one. When I had my summer tires on and the TPMS not programmed, it threw a code. After I got them updated with my own TechStream cable and software, it logged the code as "history", so I don't think the light going off managed to clear the code. IT should still be logged as a historical code in the ECU.

I don't think the OBD scanners can read the TPMS ECU. But, I'm not too up on what they can/can't do with the Prius. I'm guessing they only read the engine ECU and maybe a couple others.

 

From one event you learned that your Toyota service manager is incompetent or lazy and the garage that did you tires is incompetent. It was a worthwhile educational event.

I trust you also learned that you need to check the work done by shops after they are done.