I just put new tires on my 04 SR5 and sure enough, now a tire sensor warning light is on about 4 weeks later! I don't know which one is bad yet but here's my question.
The tire shop says to replace them all, which I've only done once in 288k. They say one you replace one or once one goes bad, they'll all usually start to fail. I don't know if this is true or just an upcharge strategy.
I thought I'd have just one replaced and see how it goes, because I don't think you save anything by doing it all at once. Is there any truth to this or should I just replace them as needed.
Thanks, all.

I would replace all of them or you'll be chasing sensors for the next year. I bought a reader on Amazon and 5 Denso sensors, paid a tire installer to put them in my tires and used the reader to write to the ECU. Most dealers will install the brand they sell and don't have the software to activate the Denso sensors, but there's less cost involved; cheapest route. Toyota dealerships want a fortune to replace them. The reader cost me $200 and now I can walk around and read each tire's battery status, pressure and temperature. Sensors were about $33 each. I think the tire dealer charged me $25/tire to replace the sensor and balance the tire again.

If you want to find the bad one, make sure all tires are at the correct PSI (32) then start with one of them and lower the pressure about 5 lbs. or so. If that's the bad sensor it will continue to flash the TPMS light. If it's a good sensor the TPMS light will become solid so air it up and go to the next one.

Last time I replaced tires I also replaced sensors in my wife's 2008 Accord. I used the brand my tire shop was offering. None of the Honda sensors had yet failed, but age was getting up, and I figured preventive maint. was worth it.

The batteries in our factory tpms sensors obviously have a lifespan. There does not seem to be any manufacturing code or date on these products.
If anyone has figured out how to measure electrical charge or active life left for our factory tpms sensors- please share.

My 2017 SR5 has the factory sensors which output pressure to my Scanguage2. It is nice to see all 4 tire pressures at a glance, especially if driving where a tire failure could cause loss of control. Like driving S. Utah at 85-90 mph on a 2 lane highway with a steep shoulder and 18 wheel big trucks also driving 85-90 (faster on downhills). Or driving LA freeways at 70+ with vehicles scarcely 2 car lengths separated and always a vehicle on both sides.

Any Toyota service center can read the sensors. There are model numbers printed on the sensors but it's also coded into them, which the scanner can read. There are other handhelds capable of reading them. I bought an Autel Maxi TPMS TS501 in 2022 for $200 and it is capable of reading them and probably the ones in your Honda as well.

I had a L/F tire blow out on a 25 year old Camry V6, 4-lane Interstate, rush hour at 75 mph. Got off at the exit I was about to pass; no problem steering

I had a trailer tire disintegrate on my 17' Ranger bass boat at 75 mph on an Interstate and the trailer was bouncing all over the place. I had no trouble pulling my 4Runner into the emergency lane.

I pull a 23' Airstream travel trailer with my 4Runner, running 65-70 mph. I've never had a handling problem with it.

Toyota makes a heck of a vehicle. I have no worries about handling with any of them.

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A blowout on the bass boat at 75mph. LMAO

I have same problem with an original tire sensor that finally went bad. Going to get the reader ArthurKotb mentioned and replace just that one if I can. Seems like everyone goes aftermarket once these fail.

Thanks everyone for your imput. Here's my question. The Denso's that are sold on Rock Auto say they don't need to be programmed or cloned. Since my tire monitoring system has one light for all the tires, do I still need to input the number of the sensor into the system, or is it ready to go?
Can the tire dealer do that with the Denso if the numbers need to be entered so you can tell which tire position is which number sensor?
Thanks again.

Looks like you have an '04 like I do. I didn't have to do anything to the new sensors to activate them, although on Amazon it says you do. I had the tire dealer just install them then used my scanner to write the IDs to the ECU, replacing the old ones. My experience with tire stores is that they don't have the Techstream software to do this. The Autel MaxiTPMS tool can do this.

The IDs are scanned by the tool and uploaded to the ECU. If you don't use a scanner the TPMS system just looks for the old sensors because that's whats still in the ECU.

It was no picnic changing it. The steel belt had wrapped itself into the caliper. Trailer was bouncing all over the place.

I've had good luck with support on the Autel. They have an email address but they just reply with "call us". The US team couldn't help but they opened a ticket with the support team in China and I got a reply that evening. Now I can check the tire pressure, temp, battery status etc. just by walking around the vehicle. I've been very pleased with it.

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Okay, not trying to sound like a moron, but let me see if I understand this. I could install the denso sensor and even without the obd scanner, it would still report low pressure. But if I used the scanner, I could input which sensor it to which wheel which will allow me to locate the bad sensor in the future?
Thx.

The new sensor doesn't have to be programed....but the new sensor's "ID" has to be entered into the ECU with a scanner/special tool so it can be detected by the ECU, otherwise the ECU will not know/recognized the new sensor so it will be just like the old sensor which has a dead battery and no longer detected by the ECU.

AuSeeker has it right, but to add a bit to his answer...

The TPMS installed in the 04 4Runners will not tell you anything about an individual sensor. The light comes on if 1 or more tires is low. The light will flash if 1 or more sensors has failed (low battery or sensor is no longer reporting).

The TPMS system works with the ECU so each sensor's ID needs to be uploaded to the ECU. You can replace a single sensor but, at least with my scanner, all of the sensor IDs get written to the ECU when you write the new sensor.

The Autel scanner I have reads / writes the sensor info from/to the ECU. The program has you start at the F/L tire, take a reading then move to the F/R as you go around the car, then finally the spare. When this is complete you have a status of each sensor, so you will see any that are bad. If they are new sensors you connect the included cable to the scanner and OBD port, then start the process to write these new sensor IDs to the ECU.

So yes, you could use this Autel scanner to find the bad sensor or low tire. You could also just air up all the tires to 32 psi then (ignition on but engine not running) lower the tire pressure in each tire one at a time. If the light continues to flash, that sensor is bad but if the light is solid then it means low pressure. Air up that tire and test the next one. It's slower but cheaper.

I know this can be confusing. There are several YouTube videos on the Autel I have. Just search for autel scanner maxitpms ts501

4th gen 4runner Service Manual

• Tire Pressure Warning System: Parts Location
• Tire Pressure Warning System: System Diagram, System Description
• Tire Pressure Warning System: Registration, Test Mode Procedure
• Tire Pressure Warning System: Problem Symptoms Table, Terminals of ECU
• Tire Pressure Warning System: Diagnosis System
• Tire Pressure Warning System: DTC Check / Clear
• Tire Pressure Warning System: Data List / Active Test, Diagnostic Trouble Code Chart

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	03700.pdf (111.5 KB, 33 views)
	037000.pdf (88.5 KB, 38 views)
	037002.pdf (363.0 KB, 43 views)
	037003.pdf (44.4 KB, 36 views)
	037004.pdf (150.2 KB, 37 views)
	037005.pdf (185.9 KB, 37 views)
	037006.pdf (37.9 KB, 33 views)

and

• Tire Pressure Warning System: C2191/91, Tire Pressure Warning Light Circuit, ECU Power Source Circuit
• Tire Pressure Warning System: TC and CG Terminal Circuit
• Tire Pressure Warning Receiver (w/ Antenna): Components
• Tire Pressure Warning Receiver (w/ Antenna): Removal, Installation
• Tire Pressure Warning Valve and Transmitter: Components, Removal, Installation, Disposal
• Tire Pressure Warning ECU: Components
• Tire Pressure Warning ECU: Removal, Installation

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	0370013.pdf (195.2 KB, 41 views)
	0370014.pdf (62.3 KB, 35 views)
	03700310.pdf (250.2 KB, 32 views)
	0370015.pdf (23.4 KB, 26 views)
	03700410.pdf (252.8 KB, 33 views)
	03700510.pdf (143.1 KB, 39 views)
	0370016.pdf (19.6 KB, 36 views)

Just Bypass the system all together. Toyota 4Runner Tire Pressure Monitoring System (TPMS) Disable Mod

Thank you everyone. That was very helpful.