GM / General Motors: Ping - shiden_kai

After adding air pressure in any tire, match them up, and then reset the
automatic gauge system.

---Bob Gross---

"Sting Ray" wrote
 
I 
same 
would 

It means that there is no one single tire that is 10 psi higher
or lower then the other three tires. So you can see that it's
not designed to be a real accurate sensor, just lets you know when
one tire is getting really low.

I'll paste in the sections from the manual, better to let GM explain
its own system.

Tire Pressure Monitor Description and Operation
The Tire Pressure Monitor (TPM) system alerts the driver when a large change
in tire pressure exists while the vehicle is being driven. The TPM system
uses the Electronic Brake Control Module (EBCM), Antilock Brake System (ABS)
wheel speed sensor inputs, class 2 serial data circuit, Systems monitor, or
the Driver Information Center (DIC) (if equipped) to perform the system
functions. The EBCM contains software to calculate relative tire pressure
differences. The software requires approximately 30 minutes of straight line
driving in three different speed ranges to complete the calibration process
to have full capability for detecting a tire pressure condition. The speed
ranges are as follows:

a.. 24-64 km/h (15-40 mph)
b.. 64-113 km/h (40-70 mph)
c.. 113-145 km/h (70-90 mph)
Each speed range has 2 modes of tire pressure detection.

a.. Monitor Mode 1
b.. Monitor Mode 2
The EBCM learns the tire pressure calibration for each speed range
independently. In Monitor Mode 1, the EBCM has only partially learned the
tire pressure calibration for the speed range and has limited detection
capability for a tire pressure conditions. In Monitor Mode 2, the EBCM has
fully learned the tire pressure calibration for the speed range and has full
detection capability for a tire pressure condition. Once the TPM system has
fully learned the tire pressure calibration the EBCM monitors the ABS wheel
speed sensor inputs, which will all be the same as the learned calibration
if the tire pressures stay the same. If the pressure increases or decreases
in one tire so to will that tires circumference and radius, which causes
that wheel speed sensor input to change. The EBCM recognizes this change in
wheel speed as a tire pressure condition. If the pressure in one tire
becomes at least 69 kPa (10 psi) higher or lower than the other three the
EBCM turns on the TIRE PRESS indicator on the systems monitor. On vehicles
equipped with a DIC the EBCM commands the DIC to display the CHECK TIRE
PRESSURE warning message via a class 2 serial data circuit. The DIC message
nor the Systems Monitor indicator appears if more than one tire pressure is
high or low, or if the system is not properly calibrated. The system does
not alert the driver to which tire pressure is high or low. If the tire
pressures are at the specified psi the TIRE PRESSURE NORMAL message is
displayed when selected on the DIC. To clear the TIRE PRESS indicator, or
the CHECK TIRE PRESSURE message, refer to Tire Pressure Monitor Reset
Procedure .



Tire Pressure Monitor Reset Procedure

Important
There are 3 ways to reset the Tire Pressure Monitor (TPM) system. After
resetting, the TPM system requires up to 30 minutes of straight line driving
in each of the 3 speed ranges to complete the calibration process, for more
information, refer to Tire Pressure Monitor Description and Operation . If
the TPM system does not reset using the Systems Monitor procedure, refer to
Low Tire Pressure Indicator Does Not Reset . If the TPM system does not
reset using the Driver Information Center (DIC) procedure refer to Driver
Information Center (DIC) Switch(es) Inoperative in Instrument Panel, Gages,
and console. If DTC C1245 remains current, refer to Diagnostic System
Check - Tire Pressure Monitoring .


Using the Systems Monitor
1.. Set all tire pressures to the recommended kPa/psi. Refer to Tire
Inflation Pressure Specifications in Maintenance and Lubrication, or to Tire
Placard in General Information.
2.. Turn ON the ignition, with the engine OFF.
3.. Press and hold the TIRE PRESS RESET button until the TIRE PRESS
indicator begins to flash.
4.. Release the TIRE PRESS RESET button and the TIRE PRESS indicator will
turn off.
5.. Use the scan tool in order to clear the TPM DTC.
Using the DIC, if equipped
1.. Set all tire pressures to the recommended kPa/psi. Refer to Tire
Inflation Pressure Specifications in Maintenance and Lubrication, or to Tire
Placard in General Information.
2.. Turn ON the ignition, with the engine OFF.
3.. Press the MODE button until TIRE PRESSURE is displayed.
4.. Press and hold the RESET button until TIRE PRESSURE RESET is
displayed.
5.. Release the RESET button, TIRE PRESSURE NORMAL is displayed.
6.. Use the scan tool in order to clear the TPM DTC.

Hope that helps.

Ian

I suspect the tires are all low on pressure because of the temperature
change in this part of the country. Tomorrow I'll check 'em and top them
up, if necessary. Thanks a million Ian!
"shiden_kai" <com> wrote in message
newsb_lb.114$.. 
When 
pressure 
change 
(ABS) 
or 
line 
process 
full 
has 
wheel 
decreases 
in 
message 
is 
driving 
more 
to 
Gages, 
Tire 
will 
Tire 

"Robertwgross" <com> wrote in message
news:news.cs.com... 

Thanks Bob! Ian just advised me how to reset the system if necessary.

Ian, I just had a call from my son who informs me that his '98 Grand Am died
today. He was on the highway when he says he heard a high pitched whining
noise just before "all the dash lights came on", apparently including the
Service Engine Soon light. There was no smoke or clunking sounds. He said it
seemed to lose power, but he managed to take an exit ramp into a small town
and parked it at a Canadian Tire lot before shutting it off. Unfortunately
there is no GM dealer anywhere near where the car is, so he went into
Canadian Tire and asked them to check it out. He said that they came out and
started it up but it wouldn't shift into any gear until they raised the hood
and did something. Also, the warning lights were all still on. It was late
in the day and they are going to check it out tomorrow. The car has the 3.1
V6 in it and has over 200,000 kilometres on it, so I wouldn't be surprised
if it's computer related. Any ideas what we may be looking at here problem
wise and cost? Thanks for your usual thoughtfulness.

"Sting Ray" wrote
 
3.1 

First thing that comes to mind is an alternator problem.
Pretty common failure on GM vehicles in general.

Let us know what the diagnosis is. If it turns out
to be the alternator, diagnosis and labor should
be right around the 1.0-1.5 hrs range. Price of the
alt is hard to know. I don't know what CT uses
for their parts.

Ian

"shiden_kai" <com> wrote in message
newsFHnb.67984$.. 
surprised 
problem 
Thanks Ian! I'll give you the diagnosis tomorrow.

> snip

Ian, it's interesting how the light of day changes the diagnostic symptoms.
My son now tells me that there were only 3 lights illuminated on the dash -
the "service engine soon" light, the "brake warning" light and the
"emergency brake warning light" (? I didn't know there was such a thing!)
Also, he told me that CTC started the engine with no problem, but had to do
something under the hood to get it into gear. He also said that the engine
seemed to be running okay and he surmised that the "drop in power" that he
thought he noticed on the highway may have actually been the transmission
up-or-down shifting.

CTC called him this morning and said that they thought the problem was the
ABS sensor, so he gave them the go-ahead to replace it. Then they called
back and said that it still wouldn't shift into any gear. Now they think the
problem is the shift linkage. They had to order in a new shift linkage which
they said will be in tomorrow. I assume that they had to order it through a
GM dealership. This saga and increasing repair costs will continue tomorrow.
I wish he had been able to get it into a GM shop where I suspect they would
be more familiar with the symptoms!