2005 Buick LeSabre "Check Tire pressure" light is on, all pressures equal and normal

The light has been coming on for the last couple of weeks. I can reset the light by pushing the dash button. On a 700 mile trip last weekend, I probably reset it half a dozen times. The tires are all at 30 PSIg. Two tire gauges agree. I don’t know how the system works. I don’t think there is a sensor in each wheel like some later cars have. I suspect it works off of ABS sensors and wheel revolutions. The ABS light is not on, nor has it been.

The right rear tire has been replaced with one of the same size, but a different brand. This issue started a month after that. Can that tire have a different revolution length per rotation and cause this issue?

Correct On The First Paragraph. You Have Figured It Out.
I Think You’re Onto Something With The Second Paragraph.

CSA

Years ago, I put two new tires on my wife’s 86 Dodge Colt. Same size, different brand. At speeds of 35-40 mph, the car started shaking badly. Once I was home, I could seen the difference in size between the tire brands. Four matching tires solved the problem.

After that, if I had to replace a tire, I always got the same brand.

Ed B.

You’re correct that the vehicle has an indirect TPM system.

Try taking some brake parts cleaner and blast the brake dust off the wheel speed sensors.

Tester

in a word: yes. even the same brand and model tire could cause this if you have 3 worn tires and one new, due to the difference in circumferance and revolutions per mile.

Are You Resetting By Pressing And Holding The Reset Button Until The Light Begins Flashing And Then Releasing It, Putting Out The Light ? I Think That’s The Only Way, But I’m Just Making Sure.

CSA

Well, that explains that. Unfortunately when you’re on the road, sometimes you have to buy whatever tire is available. The new one definitely has much deeper tread than the other three.

Thanks for your help.

I don’t think you need a perfect match with the tires. If the reset proceedure is done correctly the computer with learn your tire diameters.

Turn the ignition switch to RUN.
Press the GAGE INFO button on the DIC until “TIRE PRESSURE” appears on the display.
Press and hold the DIC RESET button for about five seconds. After five seconds, the display will show “TIRE PRESSURE RESET”. If “TIRE PRESSURE RESET” does not appear in the display after about five seconds repeat the procedure. If it does not work after two tries, see Testing and Inspection.
After you release the DIC RESET button, “TIRE PRESSURE NORMAL” will appear in the display. The system completes the calibration process during driving. Calibration time can take 45 to 90 minutes, depending on your driving habits. After the system has been calibrated, the system will alert the driver that a tire is low, up to a maximum speed of 65 mph (105 km/h).

@Nevada_545 I’ve just been pushing the reset button momentarily as soon as it beeps and I see the message. As soon as I push the button, the message goes out. I take it I need to do this proceedure as you stated. I’ll try that as soon as I see the light again.

I Concur With Nevada_545.
CSA

Our automobile life will now be described as BST and AST.