TPMS Wrong Reading

[SteveMansur]

Changed tires today and the TPMS are showing incorrect readings. 1 wheel is too high (60kpa over) and the rest are slightly off as well (30kpa). Will the relearn procedure reset the sensors or is there another way to solve the issue?

 

[iamdub]

If you changed the tires, they may not have adjusted the air pressure to where it should be. It's common for tires to take higher pressure to seat the beads. Once the beads are set, then the air should be let out until the pressures are set according to the vehicle's specs. Check and adjust the pressures with a regular gauge then go for a drive. The sensors will update within a couple of miles, if even that far.

 

[swathdiver]

If you changed the tires, they may not have adjusted the air pressure to where it should be. It's common for tires to take higher pressure to seat the beads. Once the beads are set, then the air should be let out until the pressures are set according to the vehicle's specs. Check and adjust the pressures with a regular gauge then go for a drive. The sensors will update within a couple of miles, if even that far.

And over 25 MPH too! It's common for some tire shops to not care one whit about what the correct air pressure should be! We endeavor to get all of four on ours to within a half pound of each other and it rides so much nicer that way!

 

[SteveMansur]

And over 25 MPH too! It's common for some tire shops to not care one whit about what the correct air pressure should be! We endeavor to get all of four on ours to within a half pound of each other and it rides so much nicer that way!

Ive driven it for over 20 miles and they havent adjusted. I set my tires using an external gauge and the readings in the car are still off

 

[Bill 1960]

The relearn procedure only connects a specific wheel sensor ID to a corner of the vehicle. It does not change the pressure transmitted by the sensor.

 

[iamdub]

It's common for some tire shops to not care one whit about what the correct air pressure should be!

As a former certified tire/grease monkey, this disgusts me.

We endeavor to get all of four on ours to within a half pound of each other and it rides so much nicer that way!

Slacker! Make 'em match perfectly according to a digital gauge! lol
Also gotta match 'em when airing up or down to meet those numbers cuz some gauges are more accurate when increasing than decreasing pressure, or vice versa.

 

[iamdub]

Ive driven it for over 20 miles and they havent adjusted. I set my tires using an external gauge and the readings in the car are still off

Sounds like you do have a legitimate problem with the system. I don't know how you would pinpoint the fault on the module or the sensor in the wheel.

Maybe park next to someone with a similar generation of vehicle with a working TPMS system. Put one of their good wheels near one of yours that's reading way off. Perform the relearn procedure but substitute their wheel for yours. If that corner of yours then reads correctly, then you know you have a bad sensor. If they were working fine before you had the tires changed and this all started immediately after, then they must've damaged the sensors when changing the tires.

 

[swathdiver]

Ive driven it for over 20 miles and they havent adjusted. I set my tires using an external gauge and the readings in the car are still off

As Bill pointed out, driving the car only get the DIC to read the sensor data from each wheel, it does not adjust the air pressure. If the air pressure is off, it is off. Over the years I can recall one fellow who insisted his Remote Control Door Lock Receiver was broadcasting the wrong tire pressures to the DIC and replaced his.

Get a Tech-2 on it and see what's going on with the RCDLR and sensors before you give yourself a headache and potentially waste money.

@iamdub Chris, How can I trust just the digital gauge, does it read in tenths of a psi? When we set the air, we go by the DIC AND the Tech-2 and while it does not show half pound increments I know that it goes by them and that is how we're able to get them so close. I'd love to be able to get them all exactly the same for the DIC with less hassle so am all ears if that digital one is more precise than whole numbers. AND it would be great to have one of those dial and go ones instead of counting Mississippis!

 

[Fless]

As Bill pointed out, driving the car only get the DIC to read the sensor data from each wheel, it does not adjust the air pressure. If the air pressure is off, it is off. Over the years I can recall one fellow who insisted his Remote Control Door Lock Receiver was broadcasting the wrong tire pressures to the DIC and replaced his.

Get a Tech-2 on it and see what's going on with the RCDLR and sensors before you give yourself a headache and potentially waste money.

@iamdub Chris, How can I trust just the digital gauge, does it read in tenths of a psi? When we set the air, we go by the DIC AND the Tech-2 and while it does not show half pound increments I know that it goes by them and that is how we're able to get them so close. I'd love to be able to get them all exactly the same for the DIC with less hassle so am all ears if that digital one is more precise than whole numbers. AND it would be great to have one of those dial and go ones instead of counting Mississippis!

Get yourself one of the Accutire gauges -- they have all sorts of designs and read to the half pound. I prefer the classic one: https://www.accutiregauge.com/digit...ccutire-ms-4021b-standard-digital-tire-gauge/ but have bought three different kinds as gifts.

EDIT: I gave my buddy next door one of these for his Harley. It has a nice 90° head for tight clearances within rims. https://www.accutiregauge.com/motorcycle-gauges/accutire-ms-4710b-motorcycle-tire-pressure-gauge/

 

[iamdub]

@iamdub Chris, How can I trust just the digital gauge, does it read in tenths of a psi? When we set the air, we go by the DIC AND the Tech-2 and while it does not show half pound increments I know that it goes by them and that is how we're able to get them so close. I'd love to be able to get them all exactly the same for the DIC with less hassle so am all ears if that digital one is more precise than whole numbers. AND it would be great to have one of those dial and go ones instead of counting Mississippis!

I recently swapped back to my "race wheels" and inflated them to 34psi, using this: https://www.amazon.com/gp/product/B082CH43LB/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

It has a bleeder to adjust the pressure down, but it also can leak very slowly through the lock-on fitting. Not enough to even hear, though. I bled the pressure down to 34.xx and let it seep out the rest of the way. As soon as the screen read "34.0", I popped the fitting off. All four corners reported 34psi on the DIC, so at least they concur accurately enough to suit my OCD.