Honda HR-V: Description

TPMS SYSTEM DESCRIPTION - CALIBRATION

A calibration process is required for the TPMS module to learn the peak tire resonance values. The calibration procedure must be performed any time the tire pressures are adjusted, or when the tires are rotated or replaced. The TPMS calibration procedure is initiated by pressing the TPMS switch or the MID.

Upon the completion of system calibration, vehicle mileage and calibration data is stored in the VSA modulator-control unit. If larger diameter accessory wheels have been installed, the TPMS system needs to be calibrated to recognize the new wheel size. This procedure is performed using the HDS threshold rewriting function.

TPMS SYSTEM DESCRIPTION - LOW PRESSURE DETECTION METHODS

The Indirect TPMS establishes a baseline tire pressure reading using the wheel speed sensors and indirectly monitors tire pressure to detect pressure loss in any of the four tires.

The system uses these two methods to determine loss of tire pressure:

• Wheel speed differential
• Peak tire resonance.

Both methods make use of outside temperature sensor data to correct calculated tire pressures for ambient temperature variations.

Wheel Speed Differential

When monitoring tire pressure using the wheel speed differential method, the TPMS module compares the speed of the wheels in three different configurations:

• Diagonal comparison between the front and rear wheels
• Comparison between the two front and two rear wheels
• Comparison between the two right and two left wheels

Tire diameter shrinks as the tire deflates, causing the wheel speed to increase. Consequently, if the difference in wheel speeds exceeds the threshold, the low tire pressure/TPMS indicator turns on as shown in the step-to-step diagram below.

Peak Tire Resonance

Peak resonance frequency value learned during calibration becomes the initial value. The peak resonance frequency method compares the initial peak resonance frequency value of the two front tires and the present peak resonance frequency value of the two front tires, and detects reduced pressure of the two front tires. If the present peak resonance value becomes equivalent to 25% reduced air pressure, the low tire pressure/TPMS indicator turns ON as shown in the step-to-step diagram below.

Resonance frequency is corrected based on the outside air temperature sensor information, because resonance frequency is changed by the outside air temperature.

The TPMS module compares the peak resonance values learned at calibration. If the value drops below a 25% pressure threshold, the low tire pressure/TPMS indicator turns on.

Temporary Suspension

Certain situations, such as when the vehicle is turning, accelerating, decelerating, or braking will temporarily prevent the system from monitoring tire pressures due to varying tire loads. The TPMS module uses other devices such as the lateral acceleration sensor, the yaw sensor, the steering angle sensor, the master cylinder pressure sensor and the PCM data to determine how the vehicle is being driven.

TPMS SYSTEM DESCRIPTION - OVERVIEW

System Outline

The Indirect Tire Pressure Monitoring System (TPMS), establishes a baseline tire pressure reading using the wheel speed sensors and indirectly monitors tire pressure to detect pressure loss in any of the four tires. The low tire pressure/TPMS indicator turns ON appear when the tire pressure of any tire, or tires, falls below the specified threshold or a system malfunction is detected.

The system configuration is shown below. The system is controlled by the VSA modulator-control unit.

TPMS SYSTEM DESCRIPTION - SYSTEM DIAGRAM

The TPMS module is integrated into the VSA modulator-control unit. In order to control tire pressure monitoring, the TPMS module first receives inputs from the VSA system, which includes the wheel speed sensors, the lateral acceleration sensor, the yaw rate sensor, the hydraulic pressure sensor, the steering angle sensor, the PCM, and the gauge control module.

Then, the TPMS module sends commands to the gauge control module through the VSA modulator-control unit and issues warnings to the driver.

Fig. 1: TPMS System Diagram

DTC TROUBLESHOOTING INDEX

TPMS DTC TROUBLESHOOTING INDEX

READ NEXT: