Does anybody know, are the tire pressure sensors the same for all size rims?
Is the pressure different in the 16", 17" & 18"s? Is the correct pressure set in the cars computer ? I want to change out my stock 16" wheels/hub caps to 17"s. Just tring to figure out if I need different sensors. Thanks

 

The OEM pressure sensors will work with most rims, they do recommend changing the seal when switching rims. Your owners manual will explain how to reprogram the DIC (you can also search this site) if there is a difference in tire pressure. Being in your locale, you may want to have each a set of winter/summer wheels/tires. These work with my 07 panel ( http://cgi.ebay.com/ebaymotors/Chevy...2128QQtcZphoto ).

 

Sensors are set by computer (reset throught DIC or RDS radio depending on GM vehicle). They can be used for most tire/wheel sizes. Once set, they report low tire pressure once the pressure drops a specified number of pounds. They're not actually watching the specific pressure, just change in pressure from a set point.

 

Tim, don't think that is correct. My 08 reads specific pressures for each tire. The system you are describing uses tire rotation speeds from anti lock systems to sense a change in tire diameter and thus low pressure. My HHR uses a different system. Other GM products may use the tire diameter system but not the HHR.

AL, first thing I changed was the 16s to 17 from Tire Rack and they installed the sensors there. They work fine. Just do the two-step program from the owners manual required anytime you rotate tires and you are good to go.

 

These things are transmitters, aren't they? How do new ones get programmed? dealer? how much? every swap? is this a gotchya every time you rotate the tires too?

 

1)Yes.
2)By dealer or use method in owners manual, which is to reduce the air starting with left front.
3)Free at good dealers.
4)Yes.
5)Yes must be done after every tire rotation.

 

For those who are interested here is exactly how they work, straight from the GM service repair manual:

Tire Pressure Monitor Description and Operation
The tire pressure monitor (TPM) system warns the driver when a significant loss, or gain of tire pressure occurs in any of the 4 tires and allows the driver to display the individual tire pressures and their locations on the driver information center (DIC).

The system uses the body control module (BCM), driver information center (DIC), instrument panel cluster (IPC), remote control door lock receiver (RCDLR), a radio frequency (RF) transmitting pressure sensor in each wheel/tire assembly, and the serial data circuit to perform the system functions. Each sensor has an internal power supply with a 10 year service life.

When the vehicle is stationary, the sensors internal accelerometer is inactive, which puts the sensors into a stationary state. In this state the sensors sample tire pressure once every 30 seconds and do not transmit at all if the tire pressure does not change. As vehicle speed increases, centrifugal force activates the sensors internal accelerometer causing the sensors to go into rolling mode. In this mode, the sensors sample tire pressure once every 30 seconds and transmit in rolling mode once every 60 seconds. The RCDLR receives and translates the data contained in each sensors RF transmission into sensor presence, sensor mode, and tire pressure. The RCDLR sends the tire pressure and tire location data to the DIC via the serial data circuit where they are displayed.

The sensors continuously compare their last pressure sample to their current pressure sample and will transmit in re-measure mode if a 8.3 kPa (1.2 psi) change in tire pressure has been detected in either a stationary or rolling state. When the TPM system detects a significant loss, or gain of tire pressure, the tire pressure monitor indicator icon is illuminated on the IPC and if equipped, a check tire pressure type message is displayed on the DIC. Both the indicator icon and DIC message can be cleared by adjusting the tire pressures to the recommended kPa/psi and driving the vehicle above 40 km/h (25 mph) for at least 2 minutes.

If power is disconnected from the RCDLR or if the vehicle battery is disconnected each TPM sensor ID is retained but all of the tire pressure information is lost. Under these circumstances the RCDLR cannot assume that the tire pressures were maintained over an unknown period of time. If equipped, the DIC will display all dashes and the scan tool will indicate a default tire pressure value of 1020 kPa (148 psi) for each tire. Driving the vehicle above 40 km/h (25 mph) for at least 2 minutes will activate the sensors causing the DIC to display the current tire pressures. The J-46079 TPM special tool or the pressure increase/decrease method may also be used to activate the sensors as well.

The RCDLR has the ability to detect malfunctions within the TPM system. In the event a DTC is set, the tire pressure monitor indicator icon on the IPC will flash for 1 minute and then remain illuminated after the ignition is turned ON and the IPC bulb check has been completed. Any malfunction detected will cause the DIC to display a service tire monitor system type message. For more information on other functions of the RCDLR, refer to Keyless Entry System Description and Operation .

 

I stand corrected. When tire monitor systems first came out, I was working for Hennessey Industries. We manufactured Coats tire changers and wheel balancers, Ammco brake lathes, lifts and alignment systems, and Bada wheel balancing weights and tools. I learned how to operate all this equipment while there. We were one of the first to work with tire pressure monitoring systems as the first ones strapped to the wheel, inside the tire, and had a profound impact on tire changing, wheel balancing and general tire/wheel maintenance. These systems monitored actual pressure and were expensive and difficult to mount and calibrate. The subsequent systems that were adopted by the automotive manufacturers were much improved, and most worked by simply being told that this is the desired pressure, and if pressure deviates by a certain amount, issue a warning. Obviously, these systems have improved drastically over the years and are far removed from the systems I worked with in the '90s.

 

Anyone else had to have TPM/Remote/Security computer replaced? I just purchased '08 on March 20, traded my '06 and part of the deal was to replace the cheap abs plastic fake spoke hubcaps with my original polished aluminum wheels from the '06, no problem or so I thought. When they completed the switch out the TPM sensor was malfunctioning, they told me they had to get a machine to recalibrate it, which they did not have and bring the car back next day. Car is brought back they still can't fix it, tell me the computer is broke, supposedly it controls several other funcitons and they refuse to release the car due to safety concerns while they wait on the part. No one has the part availible and after 6 days of holding my car hostage I finally convince management to swap a computer from another car on the lot and get mine back. Hard to beleive with a new car that no one had the part available anywhere, come to find out the service guy that worked on it said the part was discontinued, while GM was remanufaturing a replacement due to some faults, but the service advisor quiclly corrected him and said that was not the case, and had nothing to do with no part available so who knows what the problem really is. I hope thats the end of it, but so far it seems more bother than it worth.

 

Al, if and when you get your new sensors, stop by and see me I will program and relearn them for free for you. You know where to find me. After all you bought your HHR at my dealer.

Night31 (aka Will)