Repair/fake-out Tire Pressure Monitor System
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Repair/fake-out Tire Pressure Monitor System
This instructable describes how a repair can be made for less than $15 (depending on what tools and parts you have on hand.
Thread Broken Stem
The tire stem of the TPM needs to be threaded. I thought at first that adding outside threads to the unthreaded part of the broken stem would allow me to screw on a new tire stem. I realized after I did this that this approach wouldn't work since the retainer nut needs to fit over the stem. This was a unnecessary sidetrack.
The approach that worked is to tap the inside of the stem and screw in a new threaded tire stem with matching threads.
I had a tap and die set that I bought at Harbor Freight for $8. The best matching tap size was 12/24. The ID of the broken TPM was 0.166".
I cut out the tire stem from an old bicycle tire inner tube. After stripping off the extra rubber, the OD of the unthreaded portion was 0.236". I used my grinder to reduce the diameter of the brass a little bit until the 12/24 die would snugly fit.
I used a little thread locker to make sure the brass part from the tube fit leak-free in the aluminum TPM.
At this point, the assembly could be re-installed in the Tundra wheel.
Fake Out Computer
I needed a way to put the repaired TPM under more than 26 psi air pressure.
I took a short section of 4" ABS pipe and glued a cap on one end and a threaded plug on the other. These parts cost me $15. Any similar closed container that you have on hand would work just fine.
I drilled a 0.4"" hole in the ABS cap and fitted the TPM. After pressuring the pipe to 30 PSI the dash board idiot light went out!! I can carry the tube next to the tire jack.
I'm a little worried that this looks like a pipe bomb if I'm ever stopped by the police. I'm thinking of putting a label on the pipe saying "Tire Pressure Monitor Tester". That should cover it.
All this could be avoided if Toyota made the engine computer open to owners without special electronics.
Major Change in 2018
2018> Times have changed and my "pipe bomb" fix stopped working. Probably the battery died.
There are now relatively cheap alternatives to my approach.
A method to disable the TPMS module has been posted in the Tundra forum - https://www.tundras.com/threads/disable-tpms.1056/...
Also, programmable sensors are available online from China for ~ $30. Not sure how easy it is to find someone willing to program your sensors for cheap. Fortunately, I save the module and the code caan be read from the back without reading it off the truck's computer. code from broken TPMS= PPA-GF33
I just bought tires at Costco. They said they were out of sensors for the Tundra (????).
I'll just leave my method for internet historians to ind.