Honda Pilot: TPMS System Description - Components

TPMS Control Unit

TPMS control unit sends signals to the initiators and receives signals from the tire pressure sensor to verify pressure sensor IDs every time the vehicle is turned to the ON mode. It also receives signals from the transmitters for tire pressure, tire temperature, and the sensor battery condition, and it continuously monitors and controls the system.

Tire Pressure Sensor

Tire pressure sensor is an integrated unit made up of each tire valve stem, a pressure sensor, and a transmitter. The tire pressure sensors are attached to the inside of each wheel, around the valve stem. The sensor transmits internal tire information using an RF (radio frequency) band wave signal one time per 60 seconds to the TPMS control unit.

Each tire pressure sensor has its own tire pressure sensor ID to prevent jamming by similar systems on other vehicles.

Initiator

The initiators are mounted on the top of each wheelwell. When the vehicle is turned to the ON mode, the initiators send a LF (low frequency) band wave signal to the tire pressure sensor, switching them from sleep mode to normal function mode. When the vehicle is turned to the OFF (LOCK) mode, the sensors switch from normal function mode back to sleep mode to extend their battery life.

Wheel

The TPMS will not work unless TPMS type wheels are installed on the vehicle. The original equipment wheels have a ''TPMS'' mark on them, and are counterweighted by adding material to counterbalance the weight of the tire pressure sensor.

TPMS System Description - Fill Assist

Overview

The fill assist function alerts the condition of the tire pressure when adjusting the tire pressure. The keyless access/TPMS control unit monitors the variation of tire pressure by the signal from the tire pressure sensor, and then outputs the signal to the MICU. The MICU will start to alert the condition of the tire pressure by flashing the turn signal/hazard lights and beeper of the keyless buzzer.

System Diagram

Operating Condition

Fill assist function operates when all the following conditions are met:

• Ignition switch: ON mode
• Vehicle speed: 0 mph (0 km/h)
• Shift position: P position/mode
• Increase/decrease rate of pressure 15 kPa (0.15 kgf/cm 2 , 2.2 psi)

However, the fill assist function may not operate under the following conditions:

• When increase/decrease rate of pressure does not reach 15kPa within 1 minute.
• When using a portable handheld compressor.

Operation

The fill assist function operates the turn signal/hazard lights and keyless buzzer in three modes depending on the condition of the tire pressure.

When the tire pressure decreases due to the puncture etc., the system will also be activated if the vehicle is on the operating condition.

The system can detect only one tire that has the variation of the tire pressure. When inflating several tires at a time, the system begins to monitor the tire that reaches to the operating condition fastest than other tires. But, the system cannot detect which tire is on the operating condition first. Thus the adjusting tire pressure should be done one by one.

TPMS System Description - Overview

The TPMS (Tire Pressure Monitoring System) continuously monitors all four tire pressure sensors and the system function whenever the vehicle is turned to the ON mode. If it detects low pressure in a tire, it alerts the driver by turning on the low tire pressure/TPMS indicator and the appropriate tire indicator. If it detects a problem in the system, it turns on the low tire pressure/TPMS indicator (starts blinking).

The system consists of the following components:

• TPMS control unit
• Tire pressure sensors
• Initiators

TPMS System Description - System Diagram

The system diagram of the TPMS is shown below.

Sunshade System Description - Control/Function