I would try a retrain on them before I did anything else. I used a magnet from
Lowe's for $4 and it worked fine. What is your weather like, has the temperature
Magnet method: With the key on, engine off, press both the lock and unlock
buttons on the key fob. A horn chirp within 10 seconds indicates the TPMS
receiver is in the programming mode. Place the magnet over the left front valve
stem until the horn chirps. This forces the LF pressure sensor to transmit its
code to the main module. Repeat the same procedure for the right front, right
rear and left rear sensors in this order. Verify all four pressure readings are
displayed on the driver information center.
or... the main item you need to re-calibrate (actually
it's "program the sensors" in the service manual lingo) the sensors is a
magnet to engage sensors during the training sequence. The GM tool is J
41760, but maybe a decent powered magnet with a horseshoe shape or hole in
it would suffice???
Make sure vehicle has been stationary for at least 2 minutes.
1 - Ignition on
2 - Press RESET to clear all IPC messages from DIC
3 - Press and release OPTIONS, scroll til IPC is blank
4 - Press and hold DIC RESET for 3 seconds
5 - Press OPTIONS again until TIRE TRAINING message is displayed
6 - Press RESET until IPC LEARN L FRONT TIRE to begin programming
7 - Install J 41760 over left front valve stem (I guess you could try a
hefty magnet now)
8 - The horn will sound indicating LF sensor is programmed
Notice - if after 15 seconds the horn doesn't sound, remove and reinstall
tool on stem. This may have to be done up to three times in some instances.
9 - IPC will direct you to LEARN R FRONT TIRE, R REAR TIRE, then L REAR
1. Programming mode will cancel if any of the following conditions are met:
- program mode exited through DIC
- ignition turned off
- all four sensors programmed
- TPM program mode for 2 minutes with no sensors learned
2. If cancelled with less than 4 codes stored, the receiver will only accept
the codes programmed up to that point.
There you have it, good luck.
For '97-00: sensor PN 10438853, $126.25 each; retaining nut PN 10268439, $1.88
each; and O-ring washer PN 10268438, $1.88 each. These are the same for all four
wheels. In 2001, GM went to an FM bandwidth sensor, with the following part
numbers: sensor with O-ring PN 2571358, $80; and retaining nut PN 25708165,
Did you get a drop in temperature down there? You can lose about a pound for
every 10 degrees it drops. If they were a little low in the first place it will
trigger the check TPMS codes. Another way to get them back on track is to let
out all of the air when the tires are warm and move it a bit to get the zero
readings and then put back the proper amount. How's your fob batteries? Part of
the link and may be needing some fresh ones.
I have a similar problem on a '99 and the message is Service Tire Pressure
Monitoring System Soon. The error codes say it is loss of communication
with the left front. I had the sensor replaced and get the same results.
What is this about the FOB battery being related to tire pressure
monitoring? Never heard of that before. I do know that the range of the
FOB is crappy and sometimes I need to be standing right next to the Left
side of the car.
Can both of these be cause by a flaky antenna on the unit that receives
these signals? I seem to remember that the FOB and the tire pressure system
share the same receiver antenna.
The FOB is a triggering signal for the setting of the training mode and can
influence an error. As for the antenna being the problem, sure, it's part of the
system but why only the left front? I think the controller is the same but the
antenna are separate and I no longer have the manual to check that. Is your
battery up to snuff in the FOB? Have you put on new tires? Do they have steel
wire side walls? New brake hoses that are steel braided? Has something changed
that could interrupt the signal from the sensor rather than the signal not being
sent? To really get picky does the new and or the old sensor have the same valve
core and cap as the other sensors, or have they been changed?
Thanks for answering.
Is your battery up to snuff in the FOB? I'll replace it, but when I try to
train the pressure sensors using the dash control, I can't get the LF to
train and since that is the first one, I can't get to the others.
Have you put on new tires? Yes, but they are the same type as the old and
the problem showed up about half way through the life of the other set.
Do they have steel wire side walls? No
New brake hoses that are steel braided? No
Has something changed that could interrupt the signal from the sensor rather
than the signal not being sent? No.
To really get picky does the new and or the old sensor have the same valve
core and cap as the other sensors, or have they been changed? Same valve
caps on all valve stems. I could move the left one to the right and the
right to the left and try to train. Can't say about the valve core, but
when the problem started, nothing had changed. After the problem first
showed up, I had my Chevy dealer check in to it and he said that testing
showed that the sensor needed replacing for about $275. I had him order it
but while waiting for it to come in, the error went away and staid for
several months now it is back and won't go away. I had the tire dealer
replace the sensor when he put new tires on but that didn't fix it. They
are the same people who put the last set of tires on and they know how to
train the sensors and like I said, I got through about 1/2 the life of the
other tires before the problem showed up.
I appreciate your suggestions.
Take a good look inside the wheel well and the sensors and cables and then
compare them to the right side. Something is maybe loose of bent just enough to
keep a clear signal from being transmitted. Could be just heavy dirt or road tar
that has disrupted the path. Then there is always the loose or corroded
connection that will drive you nuts trying to find where it is hiding.
It has been a long time since I read about the core and cap being an issue and
since then I've changed some sensors the have differing cores and it didn't seem
to affect the readings. Just a shot in the dark as to what it might be.
Although I believe it refered to training the vehicle to a new FOB,
there was a note several years ago to do training at a good distance
from other GM cars/trucks with similar security or body control modules.
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