Low Tire Pressure Warning ???
Thread Starter
Racer
Joined: Sep 1999
Posts: 465
Likes: 24
From: South Jersey
Low Tire Pressure Warning ???
HELP!! For the past couple of mornings I've gotten low tire pressure warnings. The DIC says 25 psi on all 4 tires, but when I checked them last night with my Brookstone gauge they all read 34 psi. :confused: Is it possible that all four sensors are off by 9 psi?? Should I add air until the DIC reads 28 or 30??
Melting Slicks
Joined: Jul 2001
Posts: 3,284
Likes: 3
From: Southwest Florida
Re: Low Tire Pressure Warning ??? (jefffxdwg)
I'm pasting this from one of my other posts below on the same subject:
If the DIC seems off with respect to tire pressure, you might want to check with a second (or third) gauge. If they (the tire pressure sensors) are *all* reading low/high compared to whatever you are using to check them, it is likely that the DIC is correct and your gauge is wrong. The tire pressure sensors are 4 independent units so it is unlikely that they'd all be off by the same amount. If it *is* determined that they are off, check your barometric pressure sensor. The PCM has to account for barometric pressure as part of it's calculation when displaying the tire pressure because tire pressure is the difference between the pressure inside the tire and that on the outside. About the only way all 4 sensors could be off one way or the other is a bad baro sensor.
Mike
If the DIC seems off with respect to tire pressure, you might want to check with a second (or third) gauge. If they (the tire pressure sensors) are *all* reading low/high compared to whatever you are using to check them, it is likely that the DIC is correct and your gauge is wrong. The tire pressure sensors are 4 independent units so it is unlikely that they'd all be off by the same amount. If it *is* determined that they are off, check your barometric pressure sensor. The PCM has to account for barometric pressure as part of it's calculation when displaying the tire pressure because tire pressure is the difference between the pressure inside the tire and that on the outside. About the only way all 4 sensors could be off one way or the other is a bad baro sensor.
Mike
Drifting
Joined: Jun 2000
Posts: 1,338
Likes: 0
From: Fontana CA
Re: Low Tire Pressure Warning ??? (ATM)
if the numbers on the DIC do not change after driving a while or when you add air to the tires then you probably need to retrain the computer to recieve the tire pressure sensors' signals. In my experience, when the computer stops recieving a signal it displays the last received value on the DIC.
Do a search for the relearn procedure or check section 3 of the factory service manual. The procedure is similar to the key fob training procedure.
Do a search for the relearn procedure or check section 3 of the factory service manual. The procedure is similar to the key fob training procedure.
Instructor
Joined: May 2000
Posts: 136
Likes: 0
From: Saratoga, California
Re: Low Tire Pressure Warning ??? (SoCal C5)
[QUOTE] when the computer stops recieving a signal it displays the last received value on the DIC.[/QOUTE]
True, but once you cycle the key OFF and back ON, those values are lost...
and won't come back until the sensors turn themselves on by rotating.
I like the baro sensor theory....
True, but once you cycle the key OFF and back ON, those values are lost...
and won't come back until the sensors turn themselves on by rotating.
I like the baro sensor theory....
Team Owner
Joined: Sep 2000
Posts: 25,015
Likes: 2,709
From: Far NW 'burbs of Chicago
St. Jude Donor '13
Re: Low Tire Pressure Warning ??? (Walt Boeninger)
Walt- There may be a variation on different years of the car, my '01 continued to display the old numbers for 3 ignition cycles and about 100 miles of driving when I switched wheels and forgot to re-train.
"Never turn your back on an electron!"
"Never turn your back on an electron!"
Team Owner
Joined: Mar 2001
Posts: 21,325
Likes: 3,841
From: small town in S.E Pa. PA
St. Jude Donor '03-'04
Re: Low Tire Pressure Warning ??? (ATM)
ATM: I see you are in NJ IN In Philly... the last few morings it has been in the 40's... and yes you can get a low reading in the cool morning .. if yo checked them later in the day of after they warmed up your going to get a high reading.. but there should not be 9 degrees difference in this weather.. I would trust your sensors more than your gauge.... if they show 25 psi you are going to get a low tire pressure reading.. in this weather they should be around 28 psi cold... and when hot they should be 30/ 32psi
