djbrow3
7/25/2007 7:20:19 AM
I recently changed out the tires on my '06 H3. I went from the original 265/75/16 to 285/75/16. The fit wasn't a problem. Now about 4 days later, the low tire pressure warning light has come on and stays on. I checked and there is one major difference between these tires and stock. Stock required 45psi, these new tires say 65psi. I checked all 4 tires and they are at 65 still, so I know it isn't a leak.
Is there something in the computer that needs to be changed for these new tires? I had also thought maybe when the change was done they broke one of the sensors? But if that was the case, why would it take 4 days before the light came on?
I actually have an appointment with the service dept. for oil change and such, but figured I'd see if anyone else here who has changed out tires had a similiar issue.
Dennis
7/25/2007 7:24:56 AM
There is a calibration procedure I think in the Owner's manual....And 40 PSI is enough.
djbrow3
7/25/2007 7:27:12 AM
Thanks, Dennis. When I get home tonight I'll RTFM and see if I can set calibration for the new tires.
mfish
7/25/2007 8:35:41 AM
Dude...your gonna blow a tire with that much pressure
. I hope your not getting the pressure off the side of the tire. I wouldnt go over 40. I have the stock 33's and I keep em around 37psi, 35 psi is what the door sticker says.
Dennis
7/25/2007 8:41:07 AM
No Matt...the 285's can handle 50 MAX...so 40PSI is ideal.
mfish
7/25/2007 8:51:40 AM
my point was that I wouldnt go over 40 psi for good tire wear, not that the tires couldn't handle it. The recommended pressure for the vehicle using those tires is in the door jam ( mine says 35 psi ). Most people ( not saying you do ) make the mistake of getting the recommended pressure off the tires, which as you said only lists the max.
Dennis
7/25/2007 8:54:40 AM
Don't know where he got the 65 psi though..
importkiller
7/25/2007 9:22:34 AM
EVEry tire is different as far as what it wants in air pressure for good tire wear...I don't mean every kind of tire I mean EVERY tire....have 4 tires you will normally have 4 different psi readings for perfect wear. The only way to really find what each tire wants is to make a line with chalk or a wax pencil from inner part of tire to outer part of tire on the top of the treads...then go for a drive around the block. When you get back note the line, if the entire line is gone then you are at perfect pressure as the entire footprint is making contact. If the outside edges are left and the center is worn then you are overinflated, center left and outside edges worn means you are underinflated. Every tire on your ride will need a different pressure and this process will need to be repeated several times a tire making different pressure changes...make note on paper what each tire needs so that future checks will be easy.
djbrow3
7/25/2007 9:40:11 AM
I did get the 65 psi from the side of the tire. Which is also what the tire jockeys inflated them to upon installation. When I get home tonight I'll lower them to between 45 and 50 psi based on comments here. I wasn't sure what was ideal for the 285's.
Dennis
7/25/2007 10:09:40 AM
What brand of tire do you have..I was referring to the Bridgestone duelers that came with mine..
No.. one pressure for all of them, do not vary 1 pound between them or this will set off the TPM again....That's how the sytem works..it compares diferences in tires pressures....This includes the SPARE.
importkiller
7/25/2007 10:31:13 AM
The spare has a sensor in it but it is not read, only the four corners are read. I am almost positive that the four corners are not compared to each other but instead are monitored individually.
jpac4lyf
7/25/2007 10:32:19 AM
my '07 h3 is at the dealer. I have the bridgestone adventure 33's... they mentioned they'll check all 5 sensors and may replace sensors entirely OR put on stock tires. What does this mean and how is it different than ones I have on currently?
Dennis
7/25/2007 10:45:26 AM
The way is see it, they are being compared..I'm too lazy right now to go look for it..But somewhere I read that to keep the each tire within 1.5 PSI of each other. so...that's my deduction on it it at least..You maybe right about the spare, but if you replace it with one of the road tires as during a rotation, you don't want to throw the odd ball pressure in the mix...
mfish
7/25/2007 10:57:18 AM
I think importkiller is correct on this one.
quote:
ORIGINAL: importkiller
The spare has a sensor in it but it is not read, only the four corners are read. I am almost positive that the four corners are not compared to each other but instead are monitored individually.
Dennis
7/25/2007 11:05:42 AM
Damn it..you're gonna make me go look now ain't ya.....
Dennis
7/25/2007 11:12:20 AM
Okay here is the whole ball of wax...Iwas sorta wrong about them being compared..but not completely..
Tire Pressure Monitoring System Information There is a separate sensor/transmitter in each wheel. The TPM system shares the receiver with the keyless entry system. Data from the receiver is displayed on the instrument panel, using the driver information center (DIC).
Sensors The sensor, with built-in valve stem, is inserted from the inside of the wheel, through a hole in the rim. It is retained by a nut (4 N.m, 35 lb. in.) and is sealed by a grommet. A lithium battery with a design life of 10 years powers the sensor.
Each sensor is coded differently. This permits the receiver to determine exactly which tire is over or under-inflated.
Operation The sensors operate only above 20 mph (32 kph) and transmit once per hour when parked, to preserve battery power.
If the pressure in a tire rises or falls outside the calibration limits, the condition is displayed by the DIC. The low limit is 24 psi (168 kPa) and the upper limit is 39 psi (272 kPa).
Service The sensors are lightweight, only about an ounce (28 g), and this small weight is easily accounted for during normal tire balancing.
The sensors are mounted within the well of the rim. It’s important to be careful when using a tire-mounting machine. The sensor could be damaged in two ways: either by (1) direct contact with the machinery or (2) by the bead of the tire as it is forced over the rim.
Use care when using tire machine.
Consult tire changer manufacturer’s support material for proper mounting procedures.
Sensor ruined by tire mounting equipment
The valve stem cap is made of aluminum and the valve core is nickel-plated to resist corrosion. The end of the stem serves as the sensor’s antenna.
TIP: Do not replace either the cap or the valve with standard parts. This will interfere with the sensor’s ability to transmit.
TIP: The TPM sensor is more precise than consumer-grade tire pressure gauges. It may be necessary to explain this if the customer routinely mis-inflates tires using a gas station gauge.
Receiver Programming The receiver is programmed at the factory to recognize which sensor is at each wheel location. If tires are rotated or a sensor is replaced, the receiver must be reprogrammed, following SI procedures.
If the receiver is not reprogrammed, the system will continue to report the correct pressures, but will assign them to the wrong locations on the vehicle.
TIP: There are two reprogramming methods. You must use the J-41760 magnet when a new sensor is installed. During tire rotation, you can use either the magnet or your Tech 2.
J-41760 Magnet
Magnet Method You will have only one minute between horn chirps, and five minutes overall, to complete the procedure once you start.
With ignition on, engine not running, press both lock and unlock buttons on the key fob. A horn chirp within 10 seconds indicates that the receiver is in programming mode.
At each wheel, hold the J-41760 magnet over the valve stem until the horn chirps, to force the sensor to transmit its code. You must follow this order: LF, RF, RR and LR. The horn chirps twice to indicate completion.
Scroll through the DIC readout to verify all four pressures are displayed.
Tech 2 Method With the TPM Reprogramming procedure on your Tech 2, you can command each sensor to its new l
