TÀI LIỆU OTO BẰNG TIẾNG ANH VỀ ECS and wheel aligment_HMC

WHEEL ALIGNMENT & ECS WHEEL ALIGNMENT & ECS Chonan Technical Service Training Center WHEEL ALIGNMENT & ECS CONTENTS WHEEL ALIGNMENT NECESSITY OF WHEEL ALIGNMENT WHAT HAPPENS DURING AN ALIGNMENT EQUIPMENT REQUIREMENTS -HEIGHT MUST BE RIGHT DIAGNOSIS PROCEDURE FOR ALIGNMENT -CAMBER -CASTER TOE STEERING AXIS INCLINATION (SAI) -INCLUDED ANGLE -STEERING OFFSET SET BACK -THRUST ANGLE -STEERING CENTER TOE OUT ON TURNS -DIAGNOSIS BY VEHICLE SYMPTOM -INTEGRATED FRAME AND BODY (MONOCOQUE) SUSPENSION SYSTEMS FRONT SUSPENSION REAR SUSPENSION SPRUNG WEIGHT AND UNSPRUNG WEIGHT -SIMPLIFIED SUSPENSION MODEL OSCILLATION OF SPRUNG WEIGHT - Chonan Technical Service Training Center WHEEL ALIGNMENT & ECS SEMI-ACTIVE ECS SEMI-ACTIVE ECS (Electronic Controlled Suspension) -SKY HOOK SYSTEM -SKY HOOK DAMPER - ADVANTAGE OF REVERSE TYPE DAMPER SYSTEM PERFORMANCE -CONSTRUCTION AND OPERATION OF SHOCK ABSORBER -ECS SHOCK ABSORBER DAMPING FORCE CHARACTERISTICS -SEMI-ACTIVE CONTROL -CONSTRUCTION OF SEMI-ACTIVE ECS -INPUTS & OUTPUTS -INPUTS 1) ALTERNATOR 'L' TERMINAL -2) BRAKE SWITCH 3) ECS MODE SWITCH (SPORT/NORMAL SWITCH) -4) VEHICLE SPEED SENSOR 5) STEERING SENSOR -6) THROTTLE POSITION SENSOR -7) ACCELERATION SENSOR (G-SENSOR) OUTPUTS 1) ACTUATOR RELAY 2) ECS LAMP 3) SOLENOID VALVE (PROPORTIONAL TYPE) -DTC LIST -DIAGNOSTIC TROUBLE CODE -WIRING DIAGRAM - Chonan Technical Service Training Center WHEEL ALIGNMENT & ECS WHEEL ALIGNMENT Chonan Technical Service Training Center WHEEL ALIGNMENT & ECS NECESSITY OF WHEEL ALIGNMENT Wheel alignment is just adjusting the relationship between the suspension and steering components, the wheels, and the frame of the vehicle Vehicle manufacturers determine which angles are adjustable from the factory based on need and feasibility Various adjustment mechanisms such as shims, cams, threaded rods and slotted frames usually provide enough adjustment, providing height is correct, to bring the vehicle into specification When the angles are all as specified, the car or truck is properly aligned, and the best possible compromise has been achieved among minimum rolling friction, maximum tire mileage, stability of the car on the road, and steering control for the driver Vehicle accident, road shock and general wear and tear can make some of these angles out of spec When that happens, control of the vehicle may be threatened, and the tires may begin to wear unevenly and rapidly The car needs to be realigned to have all the proper angles restored The warning signs suggesting the need for alignment are: - Irregular wear on tires Look closely at all four of your tires If one or more of them demonstrate excessive wear on one side, or wear in a cupped, scalloped or diagonal stripe pattern at edges or across the tread, or uneven wear but with "feathered" edges on the treads, an alignment could be needed - Unusual steering feeling If the steering feels stiffer than it used to, or if the wheel does not return to the center position when released, or if the car feels skittish the wheels may be out of alignment If the steering wheel pulls to one side when the front wheels are pointing straight ahead, an alignment is almost certainly needed While driving, if the car wants to pull to one side, tends to wander or weave, or is subject to front end "shimmy", you should have the alignment checked immediately There are three basic wheel angles such as Camber, Caster and Toe which determine whether a vehicle is properly aligned and goes where it is pointed These three angles must be set properly for the alignment to be correct Four-wheel alignment is essential on vehicles with front wheel drive (FWD) and independent rear suspension The rear wheels should follow the fronts in a parallel path If the rear wheels are pointed in a slightly different direction, they affect tire wear and the vehicle's stability - - Common alignment errors to avoid are: - Failing to perform an accurate vehicle inspection, including height measurement, to assure a quality alignment - Failing to pull the rear turn-plate pins during a thrust alignment Overtorquing rear hub attachment bolts, causing possible full or partial contact shim Chonan Technical Service Training Center WHEEL ALIGNMENT & ECS - deformation Remembering to inspect the vehicle for the presence of a rear shim prior to cutting a new one Other facts should be known about wheel alignments: - A wheel alignment should always start and end with a test drive - The front end and steering linkage should be checked for wear before performing an alignment - The tires should all be in good shape with even wear patterns - Pulling problems are not always related to wheel alignment, problems with tires, brakes and power steering can also be responsible It is up to a good wheel alignment technician to determine the cause WHAT HAPPENS DURING AN ALIGNMENT Before a wheel alignment, a thorough inspection of the entire undercar, including suspension parts, bushings, steering linkage, ball joints and wheel bearings, wheels and tires as well as the vehicle's frame and ride height Loosened or bent parts need to be checked Once this inspection is complete, the car will be checked and adjusted on the alignment machine in order, camber, caster and toe, beginning with the rear wheels Items to be checked before the measurement of wheel alignment are : - Tire inflation pressure (under standard condition) - Uneven wear of tires or difference in tire sizes - Ball joint play due to wear - Tie rod end play due to wear - Front wheel bearing play due to wear - Lengths of left and right strut bars - Deformation or wear of steering linkage parts - Deformation or wear of parts related to front suspension - Chassis-to-ground clearance Alignment checks are recommended whenever steering, suspension parts, or some front-wheel drive (FWD) driveline components are replaced, or when new tires are installed, or when customers complain of vehicle pulling or abnormal tire wear such as scuffing, cupping or more accelerated wear on one side of the tire Chonan Technical Service Training Center WHEEL ALIGNMENT & ECS The type of alignment performed usually is conditional upon the amount of adjustment that's feasible on a particular vehicle, as well as the shop's equipment capability On solid-axle, rearwheel-drive (RWD) vehicles, for example, a thrust alignment is usually performed so the front wheels are aligned to the rear axle The drive direction of the rear axle is referred to as the thrust line, which should in theory be the same as the geometric center of the vehicle Thrust line Geometric center line A four-wheel alignment involves adjusting the rear wheels to achieve proper camber and toe and a thrust angle as close to zero as possible, then adjusting the front wheels to the same vehicle centerline Four-wheel alignments are recommended for most FWD cars, MPV(Multi Purpose Vehicles), some SUV(Sport Utility Vehicles) and RWD vehicles with independent suspension EQUIPMENT REQUIREMENTS To perform a four-wheel alignment, a four-sensor machine is required Turnplates or rear slip plates at all four corners are needed during both four-wheel and thrust alignments The rear wheels must be allowed to relax to their normal position to achieve proper readings whether they are to be adjusted or not In addition to providing caster, camber and toe readings, alignment machines can be used as a diagnostic tool Diagnostic angles such as Steering Axis Inclination (SAI), Included Angle (IA), Setback and Turning Radius can help the technician to identify problems that otherwise might be overlooked When the SAI reading is combined with the camber reading, the sum of the two angles equals the IA Using SAI/IA and camber will help identify a bent or shifted component The optimum setting on all vehicles for Setback is zero, so either a positive or negative Setback reading indicates cradle shifting or some other component has moved Turning Radius, also referred to as toe-out on turns, is determined by the steering arms relative to the lower steering pivot When the vehicle is steered into a turn, the steering arms cause the wheels to turn at different angles, creating a toe-out condition If the turning radius is incorrect, Chonan Technical Service Training Center WHEEL ALIGNMENT & ECS inspect the steering arm and lower steering pivot components for damage Using the turnplates on alignment equipment, a technician can check for a bent steering arm by measuring the amount of toe-out on turns for each wheel and compare them HEIGHT MUST BE RIGHT Some of today's alignment equipment also can diagnose ride height, which is critical to proper alignment and suspension geometry Ride height is the angle that all wheel alignment angles are built around and should be kept within manufacturer specifications for optimum performance of the entire steering, suspension and driveline system When vehicles have been modified from the manufacturer's original design, factory alignment settings may no longer apply Altering tire sizes may upset the spindle's distance from the ground, which can have an effect on scrub radius Raising or lowering vehicle height may alter the suspension and steering systems' geometry during deflection and cause excessive toe change or stress some parts beyond their limits Weak, sagging springs can force the entire steering and suspension system to go out of proper alignment, which spells problems for any vehicle A correct alignment with a sagged suspension can still produce tire wear and handling problems during dynamic operation The best way to fix the ride height is to replace the springs (Note: springs should only be replaced in matched pairs) Changes in riding height will affect camber and toe so if springs are replaced or torsion bars are adjusted, then the wheel alignment must be checked to avoid the possibility of tire wear It is important to note that the only symptom of weak coil springs is a sag in the riding height If the riding height is good, then the springs are good [Camber change by a sagging spring] Air suspended vehicles may have a specified procedure that is necessary to achieve the correct alignment height prior to adjustment On some air suspension systems, it is first necessary to allow the air in the air spring to reach shop temperature prior to alignment Failure to detect incorrect chassis height can often lead a technician to a wrong diagnosis, such as attributing the lack of adjustment range to a bent frame DIAGNOSIS PROCEDURE FOR ALIGNMENT Chonan Technical Service Training Center WHEEL ALIGNMENT & ECS Tire, brake and driveline problems are often mistaken for an alignment problem by the vehicle owner, so the customer should be consulted as to what made them think the vehicle needs aligning Begin by asking the customer a few simple questions, such as: What is your vehicle doing to make you think you need an alignment? Does it pull? When does it pull? Is the steering wheel straight? Are the tires worn unevenly? Next, verify the problem with a test drive and a complete inspection of the tires and the wear patterns they display that indicate a steering or suspension problem If the customer is getting new tires, examine the old ones for unusual wear before they come off the vehicle Explain to the customer how new tires will experience the same wear as the old ones unless the underlying cause of the problem is corrected If a loose steering or suspension part is discovered, show the customer the actual problem If possible, demonstrate a properly functioning part on a similar vehicle in the shop for comparison Due to the hectic schedule in most shops, this step is sometimes overlooked even though people learn best from hands-on experience It's essential to always be precise when discussing factory specifications for steering and suspension components Some chassis parts must exceed a listed tolerance for looseness to actually require replacement In many cases, the part can be within its tolerance range but still contribute to tire wear, alignment and handling problems Some amount of looseness within this spec could create problems for the driver of the vehicle, but the replacement is not required until the tolerance is reached When making a service suggestion to the customer, explain that although the ball joint may be within its listed tolerance, the looseness could allow wheel movement and create alignment angle changes A part that is loose, but still within its listed tolerance, should never be described as bad Some steering components such as tie rod ends may not have a listed tolerance Inspection of these components may rely entirely on the technician's judgment, using hand pressure or some other approved method as a measure of excessive looseness CAMBER Camber is the angle of the wheel, measured in degrees, when viewed from the front of the vehicle The front wheels of the car are installed with their tops tilted outward or inward This is called camber and is measured in degrees of tilt from the vertical When the top of a wheel is tilted outward, it is called positive camber Conversely, inward inclination is called negative camber Chonan Technical Service Training Center [Camber] WHEEL ALIGNMENT & ECS On many vehicles, camber changes with different road speeds This is because aerodynamic forces cause a change in riding height from the height of a vehicle at rest Because of this, riding height should be checked and problems corrected before setting camber For many years the trend has been to set the camber from zero to slightly positive to offset vehicle loading, however the current trend is to slightly negative settings to increase vehicle stability and improve handling If the camber is out of adjustment, it will cause tire wear on one side of the tire's tread If the camber is too far negative, for instance, then the tire will wear on the inside of the tread On many front-wheel-drive vehicles, camber is not adjustable If the camber is out on these cars, it indicates that something is worn or bent, possibly from an accident and must be repaired or replaced [Camber wear pattern] Positive Camber Vehicle load Slight positive camber results in a dynamic loading that allows the tire to run relatively flat against the road surface Positive camber also directs the weight and shock load of the vehicle on the larger inner wheel bearing and inboard portion of the spindle rather than the outboard bearing Positive camber in moderation results in longer bearing life, less likely sudden load failure, and as a side benefit, easier steering Excessive positive camber wears the outside of the tire and can cause wear to suspension parts such as wheel bearings and spindles Giving the wheel positive camber causes the load to be applied to the inner side of the spindle, reducing the force acting on the spindle and the steering knuckle The reactive force, which is equal in size to the vehicle load, is applied to the wheel perpendicularly to the road this is divided into perpendicular force to the axis of the spindle and parallel force to the axis of the spindle which forces the wheel inward, helping to prevent the wheel from slipping off the spindle The inner wheel bearing is made larger than the outer one in order to bear this load 10 Inner wheel bearing [Vehicle load & Wheel bearing] Vehicle load Outer wheel bearing Chonan Technical Service Training Center [Vehicle load & Wheel bearing] WHEEL ALIGNMENT & ECS d Output signal 7) ACCELERATION SENSOR (G-SENSOR) In order to detect a plane, at least points are required There are G sensors: front right, front left and rear ECSCM will detect the G sensor output voltage and determine the vertical movement of the vehicle ECSCM will use the G sensor input signal as the main signal to control the anti-bounce, anti-pitch, and anti-roll Sensor connector a Application: Main signal for driving feeling (3EA) [Acceleration Sensor] b Specification - Input Voltage: 5V±0.25V - Output Voltage: 0.55 ~ 4.45V - Nominal Sensitivity: 2.0V/g - Range: +1g ~ 1g - Operating Temperature: 40 ~ +125 ℃ c Sensor location (FR sensor, FL sensor, Rear sensor) d Sensor IC construction 47 Chonan Technical Service Training Center WHEEL ALIGNMENT & ECS e Sen sor circuit and sensor output characteristics f Current data & sensor output 48 Chonan Technical Service Training Center WHEEL ALIGNMENT & ECS [At plane surface] [At around 45º] [At around 90º] 49 Chonan Technical Service Training Center WHEEL ALIGNMENT & ECS [When the sensor is open] OUTPUTS 1) ACTUATOR RELAY ECS actuator relay operation will be controlled by the ECSCM Upon the ECS actuator relay operation, current will be provided to the damping force variable solenoid valve via ECSCM internal circuit When the generator terminal "L" voltage drops to "LOW" while running, ECSCM will quit the actuator relay operation a Application Actuator relay is activated by ECS control module and supplies power to the proportional solenoid b Specification - Consumption Power: 1.8W (at 12 V) - Operating Temperature: 40 ~ +100℃ - Control Current: 150 mA c Functions - ECU ground control - While ECS control: 0V 50 Chonan Technical Service Training Center [Actuator relay circuit] WHEEL ALIGNMENT & ECS - Out of ECS control: 12V d Current data when the relay is off 2) ECS LAMP ECS indicator lamp is located on the instrument panel, and will be on by selecting the sport mode or blink if the ECS system fails ECSCM controls the ground terminal when the switch signal is input or when the system failure is detected a Specification - Type: LED - Consumption Power: Max 25mA (at 12 V) b Application ECS lamp comes on when sport mode is selected or when there is a failure on the system c Lamp operation - Normal: OFF, Sport: ON, Failure: Flashing d ECS Control Mode & Lamp Control Specification - While running normal, the lamp is turned on/off by switch But the lamp is on in seconds after control module started a) Select Sport: ECS Lamp ON b) Select normal: ECS Lamp OFF 51 Chonan Technical Service Training Center WHEEL ALIGNMENT & ECS - Detecting troubles : If some trouble is detected, a diagnosis number coping with the trouble is recorded AT the same time “Sport” lamp goes on and off If a trouble is detected, the lamp starts going on and off - Sport lamp turns on while HI-SCAN communication e Output signal of ECS lamp 52 Chonan Technical Service Training Center WHEEL ALIGNMENT & ECS 3) SOLENOID VALVE (PROPORTIONAL TYPE) Applied current to the damping force variable solenoid valve will be controlled by the ECSCM Depending on the current applied, the spool valve in the actuator will move to change flowing route and lead to the damping force variation a Application: Main signal for driving feeling b Specification - Output current range : 0.3A ~ 1.3A 1) Rebound Hard / Compression Soft : 0.3A 2) Rebound Soft / Compression Soft : 0.8A 3) Rebound Soft / Compression Hard : 1.3A - Rated voltage : 12V - Operating voltage : 10 ~ 16 V - PWM frequency : 500Hz c Location 53 Chonan Technical Service Training Center WHEEL ALIGNMENT & ECS d Construction In the case of rebound process, the procedure to change damping force hard is; - Reduce the current of solenoid actuator then the pilot spool moves to right side and choke the area of control port, so that the damping force of orifice control increases and the room pressure behind the main valve is increased, As the result, the damping force turn to hard due to increase of opening pressure of main valve The procedure to change damping force soft is; - Increase the current of solenoid actuator then the pilot spool moves to left side and open the area of control port, oil flows both through the orifice of the rebound side main valve and the control port of the pilot spool, so that the damping force of orifice control reduce, and same time the room pressure behind the main valve decrease due to the pressure drop of the main valve orifice, 　 then the blow off point of main valve moves to lower side, As a result, the damping force turn to soft In the case of jouncing process, if you want to make it hard, the current should be increased, if you want to make it soft, the current should be decreased e Operation (HARD/SOFT mode) When the applied current drops below 0.8A, the spool valve moves to the left as the force of the spring against the spool valve overcomes the magnetic force of the solenoid coil During the compression stroke, the oil flows from the compression chamber to the base chamber freely because the spool valve remains open As a result, the compression stroke remains soft As the spool valve moves left, the opening for the rebound chamber to the base chamber gets 54 Chonan Technical Service Training Center WHEEL ALIGNMENT & ECS smaller restricting oil flow When applied current reaches 0.3A, the oil path is closed completely and the rebound stroke becomes the hardest f Operation (SOFT/HARD mode) If the applied current increases above 0.8A, the spool valve moves to the right decreasing oil flow to the compression chamber When current increases to 1.3A, the opening between the compression chamber and the base chamber is closed completely At 1.3A, the compression stroke becomes the hardest During the rebound stroke, the oil path from the rebound chamber to the base chamber through the spool valve remains open, so the rebound stroke remains soft g Operation (SOFT/SOFT mode) When the applied current is 0.8A, the damping force is soft for both compression and rebound strokes At 0.8A, the spool valve passageways are both open The oil inside the rebound and the compression chamber flows easily to the base chamber through the spool valve h Current data & output signal * While SOFT/HARD control * While SOFT/SOFT control 55 Chonan Technical Service Training Center WHEEL ALIGNMENT & ECS * While HARD/SOFT control DTC LIST 56 Chonan Technical Service Training Center WHEEL ALIGNMENT & ECS No Failure Cancellation Condition ACG L-Terminal ACG L-Terminal output changes LOW to HIGH Steering sensor Sensor output voltage outputs normal value Speed sensor Sensor output more than km/h Acceleration sensor (Including connector disconnection) Acceleration sensor output is within the range from 2.5-0.2V to 2.5+0.2V 10 11 12 Sensor power source voltage Damping force change actuator FR Damping force change actuator FL Damping force change actuator RR Damping force change Actuator RL Actuator relay ACG L-Terminal output changes LOW to HIGH ACG L-Terminal output changes LOW to HIGH ACG L-Terminal output changes LOW to HIGH DIAGNOSTIC TROUBLE CODE BATTERY: C1101 57 Chonan Technical Service Training Center WHEEL ALIGNMENT & ECS a Diagnostic trouble description - Low voltage (Engine run): Actuator operating voltage is more than 17V over 20sec - High voltage (Engine run): Actuator operating voltage is more than 18V over 2sec b Action to be taken by ECU: Relay OFF c Cancellation condition: ACG-L terminal output changes Low to High (9~16V) over 100msec ALTERNATOR L TERMINAL: C1107, C1108 1) DTC: C1108 (Low voltage, Engine run) a Diagnostic trouble description: Output voltage is less than 8.5V over 10sec When the car speed is more than 40km/h b Action to be taken by ECU: relay OFF c Cancellation condition: output voltage is more than 9.5V over 100msec 2) DTC: C1107 (High voltage, Engine run) a Diagnostic trouble description: Output voltage is more than 16.5V over 100sec b Action to be taken by ECU: relay OFF c Cancellation condition: output voltage is less than 16V over 100msec ACTUATOR RELAY : C2124 a Diagnostic trouble description - Low voltage when on (Engine run): Actuator operating voltage is less than 8.0V over 10sec - High voltage when off (Engine off): Actuator operating voltage is more than 9.5V over 2sec when Key ON b Action to be taken by ECU: Relay OFF c Cancellation condition - Low voltage when on (Engine run): ACG-L terminal output changes Low to High (9~16V) over 100msec - High voltage when off (Engine off): ACG-L terminal output changes Low to High (9~16V) and 0V over 100msec SPEED SENSOR : C1212 (OPEN/SHORT, ENGINE RUN) a Diagnostic trouble description: TPS output duty is more than 40%, and the output less than km/h over minute b Action to be taken by ECU: Hard/Soft (F: 0.55A, R: 0.63 A) c Cancellation condition: The car speed is more than 3km/h over 10msec 58 Chonan Technical Service Training Center WHEEL ALIGNMENT & ECS STEERING SENSOR : C1259 (OPEN/SHORT, ENGINE RUN) a Diagnostic trouble description: Sensor output voltage is less than 0.8V or more than 4.6V over 30sec b Action to be taken by ECU: Stop the Roll control c Cancellation condition: Right Output Voltage is over 10msec ACCELERATION SENSOR (FR:C1279 FL:C1278 RR:C1281) 1) Open/Short (Engine run) a Diagnostic trouble description: Sensor output is less than 0.5V or more than 4.5V for minutes b Action to be taken by ECU: Stop the Ride control c Cancellation condition: Acceleration sensor output is 2.5±0.2V over 10msec 2) Signal Error (Engine run) a Diagnostic trouble description: Sensor output keeps the same level at less than 1.9V or more than 3.1V for minutes b Action to be taken by ECU: Stop the Ride control c Cancellation condition: Acceleration sensor output is 2.5±0.2V over 10msec SOLENOID VALVE (FR:C2216 FL:C2212 RR:C2224 RL:C2220) a Diagnostic trouble description: Harness wire is open over 30sec b Action to be taken by ECU: Relay OFF c Cancellation condition: ACG-L terminal output changes Low to High(9~16V) over 100msec WIRING DIAGRAM 59 Chonan Technical Service Training Center WHEEL ALIGNMENT & ECS * Refer to the shopmanual for pin assignment 60 Chonan Technical Service Training Center WHEEL ALIGNMENT & ECS SIMPLE WIRING DIAGRAM (Refer to the shopmanual for pin assignment) 61 Chonan Technical Service Training Center ... Specs More than Specs Bent Spindle and/ or Strut Body More than Specs More than Specs More than Specs Strut Tower IN at Top and Spindle or Strut Bent Less than Specs More than Specs Equal to Specs... Specs More than Specs Bent Lower Control Arm and/ or Lower Control Arm Mount Equal to Specs More than Specs More than Specs Spindle/Knuckle Assembly Less than Specs More than Specs Equal to Specs... than Specs Bent Control Arm or Strut OUT at Top and Bent Spindle or Strut Body Equal to Specs Less than Specs Less than Specs Bent Spindle and/ or Bent Strut Body Less than Specs Less than Specs