Tire Pressure Monitoring (TPM) - Description

DESCRIPTION

The Tire Pressure Monitoring (TPM) system monitors air pressure in the four road tires (excludes spare). Pressure in the spare tire is not monitored.

There are two tire pressure monitoring systems available, a base system and a premium system. The base system does not specify how many tires are low or where they are located. The premium system does so.

The Base TPM system consists of tire pressure monitoring sensors attached to each road wheel through the valve stem mounting hole, a central receiver module (WCM) and an indicator lamp.

The Premium TPM system consists of tire pressure monitoring sensors attached to each road wheel through the valve stem mounting hole, a wireless control module (WCM) three wheel sensor transponders located in three of the four wheel wells, an electronic display, and an indicator lamp.

The receiver circuit for the TPM system is integrated into the WCM for non-remote start vehicles. For factory installed remote start vehicles, the remote start antenna is external to the WCM. The WCM can also include the Remote Keyless Entry (RKE) receiver, Remote Start (if equipped), and the Sentry Key Immobilizer (SKIM) receiver. All four receivers share a number of common components. The WCM decodes the RF signals transmitted by each of the vehicle's tire pressure sensors. The decoded information is used to determine if "warning" or "fault" conditions exist within the TPM system.

Upon detection of a warning or fault condition, the WCM will send a request to the module that controls the indicator lamp (and the text display if equipped with the Premium system) via the vehicle bus system to illuminate or flash the indicator lamp. Also, upon detection of a warning or fault condition, the electronic display will send a request to sound the "chime".

The WCM will store all warning and fault conditions, placard pressure values and low-pressure threshold values (lamp ON and OFF) in memory that can be accessed through diagnostic communication. If new sensors are introduced to the vehicle, the data stored for the sensor being replaced will be deleted.

The WCM will store all wheel sensor ID's and locations and faults in memory that can be accessed through diagnostic communication. All other data values transmitted from each active wheel sensor (not the spare tire) shall be stored in the WCM memory.

The WCM automatically learns and stores the sensor IDs while driving "within 10 minutes continuously above 15 mph (24 km/h)" after a sensor has been replaced. The learning sequence will initiate when the vehicle has been stopped for more than 20 minutes.

NOTE: A new sensor ID can also be programmed directly into the WCM by using a RKE-TPM Analyzer in conjunction with a Scan Tool. Once the new sensor ID has been programmed, the RKE-TPM Analyzer can be used to update the TPMS by activating the sensor.