胎压监测系统

Warning Lamps
1. Amber warning indicator = 25% 2. Red warning indicator = 35%
A. Low Line System B. High Line Message Centre
TPMS
Customer Education:
• Tyre pressure need to be checked and adjusted when cold
WHEEL SENSOR
LF INITIATOR
CAN BUS
Rx
ECU
WHEEL SENSOR
LF INITIATOR
FULL SIZE SPARE WHEEL
TPMS
TPMS
TPMS
System Operation:
• On driving off, the ECU polls each road wheel with LF (125 KHz) signal via the initiator in turn (starting LHF going clockwise)
• On High-Line vehicles, the message centre replaces the red warning indicator and provides additional information about the position of the affected wheel(s)
• Spare Wheels > If a new sensor is fitted in the spare position, the unique ID must be programmed diagnostically or the wheel will not be monitored > It will be provided on a label for complete assemblies, and is also printed on the casing of each sensor > If a known running wheel is exchanged with the spare, it will then be monitored as the spare
• LED on = Light Tyre Loading • LED off = Heavy Tyre Loading
• Preference = LED off (Normal Position)
• Pressing the switch and indicating the additional load increase cancels the switch LED and resets the system to the higher threshold
• As each wheel responds, it is assigned a position on the vehicle and monitored for the remainder of the drive cycle in that position
• The initiator is not used again unless the speed reduces to below 12 mph (20 km/h) for 15 minutes
Green area : Tyre bead above wheel rim
Red area : Tyre bead in wheel well
Fitting machine direction of rotation
TPMS
Wheel Learning:
• Replacement Wheels > If new wheels with sensors are fitted to a running position, they will be learnt when the vehicle is first driven and no other action is required
Tyre Pressure Monitoring Sensor Fault
> When the sensor battery is low, it sends out a flag to the control module, the ECU can be checked to determine if a sensor needs replacing
Tyre Pressure Monitoring Sensor Fault
TPMS
> A warning will be displayed if RF interference around the vehicle is too strong for the system to work, but will be cancelled when interference subsides
• They respond directly to the TPMS ECU with a RF transmission (315 or 433 MHz) containing a unique ID, pressure, temperature and acceleration information
fixing torque must be adhered to • Sensor components are available as service parts
Tyre Removal
Mounting tool position to start tyre fitting
Tyre
Rim
Valve initial position
sensor must be positioned correctly in relation to the fitting arm • If the sensor is removed, the nut, seal and washer must be replaced and the sensor
TPMS
Tyre Pressures:
• Up to GVW: Fronts = 33 PSI - Rears = 42 PSI
Post - PBaidu Nhomakorabeasition Identification:
• Sensors transmit once a minute whilst the vehicle is driving (Spare every 13 hours)
TPMS
Fault Detection: > If the ECU or one-or-more sensor fails, the amber tell-tale will be lit and a warning displayed on the message centre “Tyre Pressure Monitoring Sensor Fault”
TPMS轮胎压力监测系统
Slide 1
© Land Rover 2003. Presenter / File name 8/1/2020 12:09 PM
TPMS Schematic
1. Initiators接收器 2. Wheel Sensors轮胎压力 3. Instrument Pack仪表盘 4. TPMS ECU电脑 5. Fascia Switch Pack仪表
• Pressure reduces as air cools
• If checking whilst hot then pressure should be set higher to compensate (not recommended though)
Temperature Change Examples:
• There are two levels of driver warning > Amber indicator at 25% deflation (Front 33 PSI = 25 PSI) (Rear 42 PSI = 31 PSI) > Red indicator at 35% deflation (Front 33 PSI = 21 PSI) (Rear 42 PSI = 27 PSI)
Power Supply 电源
Fuse 32 (15 amp) Battery Supply
Fuse 36 (5 amp) Ignition Supply
LF INITIATOR
LF INITIATOR
WHEEL SENSOR
CLUSTER
WHEEL SENSOR
125 Khz
315 Mhz 433 Mhz
NAS – One threshold ROW – Two thresholds
TPMS
Tyre Changing: • The bead breaker must not be used within 90 degrees of the valve • In order to reduce the risk of sensor damage during tyre removal and refitting, the
18°C (65°F) – 33 PSI
12°C (55°F) – 32 PSI
7°C (45°F) – 31 PSI
1.6°C (35°F) – 30 PSI
Fascia Switch
• A fascia mounted switch informs the TPMS ECU of the different vehicle / tyre loading