Chevrolet Equinox Service Manual: Tire Pressure Monitor Description and Operation TPMS

Tire Pressure Monitoring Block Diagram

A5Driver Information CenterP16Instrument ClusterK9Body Control ModuleK77Remote Control Door Lock ReceiverT10Keyless Entry AntennaB2LFTire Pressure Sensor - Left FrontB2LRTire Pressure Sensor - Left RearB2RFTire Pressure Sensor - Right FrontB2RRTire Pressure Sensor - Right RearSerial Data

Hard-Wired

Wireless

P16-Instrument Cluster

P9-Driver Information Center Display

K9-Body Control Module

K77-Remote Control Door Lock Receiver

T10-Keyless Entry Antenna

B2LF-Tire Pressure Sensor – Left Front

B2LR-Tire Pressure Sensor – Left Rear

B2RF-Tire Pressure Sensor – Right Front

B2RR-Tire Pressure Sensor – Right Rear

Special ToolsEL-46079/J-46079 Tire Pressure Monitor Diagnostic ToolEL-50448 Tire Pressure Monitor Sensor Activation Tool

For equivalent regional tools, refer toSpecial Tools.

The tire pressure monitor system warns the driver when a significant loss, or gainof tire pressure occurs in any of the 4-tires and allows the driver to display theindividual tire pressures and their locations on the driver information center.

The system uses the body control module (BCM), driver information center, instrumentcluster, 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 internalpower supply with an approximate 10-year service life.

When the vehicle is stationary, the sensor's internal accelerometer is inactive, whichputs the sensors into a Stationary state. In this state the sensors sample tire pressureonce 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 accelerometercausing the sensors to go into Wake and then Drive mode. In Drive mode, the sensorssample tire pressure once every 30-seconds and transmit in Drive mode once every 60-seconds.The BCM receives and translates the data contained in each sensors RF transmissioninto sensor presence, sensor mode, and tire pressure. The BCM sends the tire pressureand tire location data to the driver information center via the serial data circuitwhere they are displayed.

The sensors continuously compare their last pressure sample to their current pressuresample and will transmit in Learn Mode-Pressure Triggered if a 8.3-kPa-(1.2-psi) changein tire pressure has been detected in either a Stationary or Drive state. When thetire pressure monitor system detects a significant loss, or gain of tire pressure,the tire pressure monitor indicator icon is illuminated on the instrument clusterand if equipped, a check tire pressure type message is displayed on the driver informationcenter. Both the indicator icon and driver information center message can be clearedby adjusting the tire pressures to the recommended pressures and driving the vehicleabove 40-km/h-(25-mph) for at least 2-minutes.

If power is disconnected from the BCM or if the vehicle battery is disconnected, eachtire pressure monitor sensor ID is retained but all of the tire pressure informationis lost. Under these circumstances the BCM cannot assume that the tire pressures weremaintained over an unknown period of time. If equipped, the driver information centerwill display all dashes and the scan tool will indicate a default tire pressure valueof 1020-kPa(148-psi) for each tire. Driving the vehicle above 40-km/h-(25-mph) for at least 2-minuteswill activate the sensors causing the driver information center to display the currenttire pressures. The EL-46079/J-46079 tire pressure monitor diagnostic tool, EL-50448 tire pressure monitor sensor activationtool, or equivalent may also be used to activate the sensors as well.

The BCM has the ability to detect malfunctions within the tire pressure monitor system.In the event a DTC is set, the tire pressure monitor indicator icon on the instrumentcluster will flash for 1-minute and then remain illuminated after the ignition isturned ON and the instrument cluster bulb check has been completed. Any malfunctiondetected will cause the driver information center to display a service tire monitorsystemtype message. For more information on other functions of the BCM, refer toKeyless Entry System Description and Operation.