The electric power steering uses an electric motor to provide a power assist for turning the automobile's wheels. It is usually a replacement for the hydraulic power steering system. The important components of the power steering system are the EPS control module, electric motor, reduction gear and the torque sensor. The reduction gear provides a power assist to the steering rack. When the steering wheel is turned, the position and range of the steering wheel's rotation are detected by a steering sensor.
The electric motor which is connected to the steering gear or column is controlled by the EPS control unit. Depending on the driving conditions, the control unit makes the motor generate the assistive torque needed to turn the vehicle's wheels. A damaged power steering system will fail to provide the required power assist. If you are looking to replace your electric power steering system components, you have come to the right place.
At Buy Auto Parts we stock a wide variety of electric power steering kits for every car make and model. We have genuine OEM replacements and premium aftermarket parts. All our car parts are thoroughly tested and come with a warranty. To view the parts that fit your vehicle, select the right year, make and model of your car on our online catalog. At Buy Auto Parts you will find high-quality electric power steering kits at unbeatable prices, and free shipping. Click here for Mobile version.
Select Make. Select Model. Electric Power Steering Kit. Thank You! All rights reserved. Secure Shopping. Search By.This advantage can also be a disadvantage if the system should shut down while the engine is running you lose steering assist. A driver unaware of this condition would become concerned if an electrical or electronic failure occurred while the engine was running, as the loss of assist would not be expected.
The configuration of an EPS system can allow the entire power assist system to be packaged on the rack and pinion steering gear or in the steering column. The system does not drag on the engine from either a power steering pump or alternator because it will not provide assist until required by driver input.
Also, there is no hydraulic fluid. A typical EPS steering application uses a bidirectional brushless motor, sensors and electronic controller to provide steering assist. The motor will drive a gear that can be connected to the steering column shaft or the steering rack. Sensors located in the steering column measure two primary driver inputs — torque steering effort and steering wheel speed and position.
Honda Fit: EPS Control Unit Removal/Installation
The steering wheel is referred to as a hand wheel in the service information. The torque, speed and position inputs, vehicle speed signal, and other inputs are interpreted in the electronic control module. The controller processes the steering effort and hand wheel position through a series of algorithms for assist and return to produce the proper amount of polarity and current to the motor.
Other inputs that will affect assist and return are vehicle speed, engine speed and chassis control systems such as ABS and electronic stability control ESC.
The brushless motor uses a permanent magnet rotor and three electromagnetic coils to propel the rotor. Most applications use a motor worm gear to drive the gear on the steering shaft or rack Fig. Pairs of six switching transistors are forward biased and move the rotor in a clockwise or counterclockwise direction. The rotor direction is determined by the sequence in which voltage is applied to coil A, B or C and returned to ground through an attached pair.
The primary purpose of the EPS controller is to provide motor control. The processor is the heart of the controller for input and output. Processor output drives the three pairs of transistors that control the rotation of the motor. Primary input to the processor comes from the torque sensor and hand wheel speed and position sensor. The processor also is an integral part of the controlled area network CAN and vehicle data buss for chassis and powertrain communications.
The controller has adaptive memory and diagnostics. The torque sensor performs the same function as the torsion bar and spool valve in a hydraulic system.
The electronic sensor uses a torsion bar in the same manner as in the spool valve. There are three different types of electronic torque sensors, and they are classified as contact and non-contact types.
Hall-type sensors monitor the twist of the torsion bar by measuring the change in magnetic flux generated by its position to the vanes located on the sensor stator rings.
Contact-type torque sensors use a wiper attached to the torsion bar and voltage divider attached to the rotating bridge attached to the motor shaft to measure the twist of the torsion bar. The rotating bridge uses contact brushes that connect to the sensor housing and connector to receive power, ground and transfer the voltage signal to the controller Fig.
The electric steering system will retain the hand wheel speed sensor HWSS for both speed and position. It will retain the four voltage divider circuits and a wiper. The voltage dividers are constructed of a resistive material on a film powered by a five-volt reference to make four degree sensing elements.
The wiper has a contact that rides on the resistive film and supplies the output signal to the controller. The signal ranges from 0. For example: The sensor produces 0.Many owners of a newer Honda Civic or Accord have had problems with diagnosing what it means when the EPS light lights up suddenly on the dash. The problem seems to be more random in the models. Many have filed complaints with Honda and the Federal government.
Some claimed they could not steer at all, while others said that turning was most difficult. These incidents have occurred at under 50, miles and at much higher mileage. Some owners have intermittent EPS problems, meaning, their power steering still functioned fine but the EPS light went on, and either went out later or went out after they turned their car off.
So far, Honda has NOT recalled cars for this problem because there have not been high numbers of incidents to warrant it. The EPS triggers are extremes. The last two will trigger the EPS light to go on, but this normal and will go out. If you do lose all power steering during driving, stay calm. Try not to turn. Pull over to a safe spot and turn off the engine. Wait at least one minute. The system should reset but may come on again until the issue is dealt with.
Try to remember if the light came on while turning, while you were at a certain speed, etc. The Honda dealer will want to know. If the EPS remains lit after started, you may or may not lose electronic power steering. In my case, the EPS comes on and off randomly at times. It remains off for a considerable time, then comes back on again.
Yet, I did not lose the power steering function. That indicated an intermittent problem with an engine speed sensor signal, a torque sensor, or the EPS control unit itself.The EPS control module CM calculates the optimum assist current based on the steering torque signal from the torque sensor installed to the steering column and the vehicle speed signal sent via CAN transmission from the PCM.
Set the steering position to 0 degrees when the ignition is switched ON engine off or on to output the steering angle when steering from that position. The EPS CM performs the steering wheel angle neutral position determination using the steering wheel angle neutral position learning function based on the wheel speed signal, lateral-G signal, and yaw rate signal while driving. Set the angle to 0 degrees during the steering wheel angle neutral position determination and the EPS CM calculates the steering angle, and outputs it.
Calculates the proper assist current based on the steering torque, and the vehicle and engine speeds, and outputs a target current to the EPS motor. Monitors the temperature of the motherboard in the EPS CM and controls the motor current gradually to prevent overheating of the system.
Even if a phase 1 open circuit malfunction in the EPS motor occurs, output current to the EPS motor is controlled so that steering assist is maintained. The main part of the system control includes the self-diagnosis function. As a result of the on-board diagnosis, when a malfunction is determined, system control is suspended or limited to assure safety while driving. Outputs the EPS status signal and the power steering malfunction indicator light illuminates on request via CAN lines.
When the ignition is switched from OFF to ON engine on and the vehicle is driven normally, the steering wheel angle neutral position is detected automatically based on the signal from the torque sensor. The steering wheel angle neutral position is cleared when 1 min or more has elapsed after the ignition is switched off. Before the steering angle neutral position auto learning is completed, the EPS CM receives a steering angle signal from the steering angle sensor via the start stop unit and outputs the signal to the other modules through the CAN communication.
The EPS CM control module calculates the optimum assist current based on the steering torque signal from the torque sensor installed to the steering column and the vehicle speed signal sent via CAN transmission from the PCM. The optimum assist current is calculated based on the steering force signal from the torque sensor and the vehicle and the engine speed signal from the PCM, and then the control current is output to the EPS motor.
The system overheating protection control lowers the current output to the EPS motor if the steering mechanism is turned from lock to lock continuously or the steering rack turning limit is reached repeatedly. During system overheating protection control, the assist force will feel weaker due to a decrease in the control current. The current output returns to normal if the temperature in the system decreases to the normal operation temperature. Even if an open circuit malfunction occurs in 1 out of the 3 phases in the EPS motor line, the backup control performs control to maintain steering assist.
As a result, even with a phase 1 open circuit malfunction, the steering assist can be maintained. If the steering wheel is operated during backup control, the steering wheel operation may feel heavier resistance and vibrating. EPS motor current control. Normal control Calculates the proper assist current based on the steering torque, and the vehicle and engine speeds, and outputs a target current to the EPS motor. System overheating protection control Monitors the temperature of the motherboard in the EPS CM and controls the motor current gradually to prevent overheating of the system.
Backup control Even if a phase 1 open circuit malfunction in the EPS motor occurs, output current to the EPS motor is controlled so that steering assist is maintained. On-board diagnostic function.
CAN communication function. Automatic configuration function. Steering wheel angle neutral position automatic learning function. Fail-safe function.
Control enabled Power steering malfunction indicator light: Not illuminated. Control enabled Power steering malfunction indicator light: Illuminated. Control disabled Power steering malfunction indicator light: Illuminated. Control is maintained in fail mode Power steering malfunction indicator light: Not illuminated. Control is maintained by gradually decreasing the motor control current However, control is inhibited if the power supply voltage is the specified value of less Power steering malfunction indicator light: Illuminated.It is really disappointed for me.
I understand that the warranty of the car is just finish, but big question for me that the EPS control unit is fragile, broken easily while running kilo meter less than K km I am working in PCBA electronic manufacturing and have a standard process of manufacturing, normally when the electronic part had been assembly in good process will be last longer.
The local dealer looks like they don't want to respond my problem and always said that warranty was over, I need to pay all the cost. I am contacting you to actually to have a good feed back to Honda about the EPS control unit performance.
I want to know, what made my EPS control unit faulty? Why it became faulty so fast just after warranty finished running kilo meter just reach about Failure analysis is necessary in that case.
It is really dangerous for me to drive this car, really safety issue. I am staying in Batam Indonesia and you can contact me through this below address. My car information" Honda Freed year GB3 1. Thank you for your respond and follow up to this problem. If you have a for-profit service, contact us. Most Common Solutions: replace eps control unit 1 reports. Find something helpful? Spread the word. Share on Facebook Retweet this page Email this page. Helpful websites No one has added a helpful site for this Freed problem yet.
Be the first! Find a good Honda mechanic Read reviews of repair shops in your area. Enter your zip code: A free service from CarTalk. Send Comment Add Complaint. Not what you are looking for? Search for something else:.It operates by actuating the brakes individually on one or more. ESP stabilizes the vehicle when.
Honda Civic Service Manual: EPS Control Unit Removal and Installation
ESP complements the familiar functions of the anti-lock brake. As well as actively intervening with the brakes, ESP. ABS prevents the wheels from locking up during braking and thus. ASR prevents the drive wheels from spinning while driving. It also. EBR reduces brake slip at the drive wheels during deceleration and. ESP prevents the vehicle from breaking away when it is oversteered.
In all situations it ensures that the vehicle does not. Brake forces are produced selectively at the. System interplay. The engine electronics ME is used to adjust the drive torque. Information on the currently engaged gear as reported by the.EPS Honda CRv 2017
The ESP system's electronic circuits also employ closed-loop control. The electronic accelerator pedal EFP and cruise-control functions. A CAN data wire supports multilateral communications between the. Advantages of ESP. Improves moving-off and acceleration capabilities by increasing. Improves active dynamic safety, since only a wheel which is not.
Automatically adapts the engine torque to suit the ability of the. Reduces the danger of traction loss under all road conditions. Significantly improves the directional stability of the vehicle.
Shortens the stopping distance in corners or on slippery roads. A flashing warning lamp within the speedometer alerts the. This can provide better. Function overview. Essentially, all the forces acting on a vehicle from outside attempt to. Example A: understeering vehicle. The vehicle pushes outwards over the front. A precisely calculated braking action is.
Example B: oversteering vehicle. The tail of the vehicle breaks away.The electronic power steering control unit was designed to help solve a constant problem that occurred with most traditional power steering systems. Under the normal, belt-driven hydraulic power steering set up, a belt was attached to a series of pulleys one at the crankshaft and one on the power steering pump.
The constant operation of this belt-driven system put a tremendous load on the engine, which resulted in loss of engine horsepower, fuel efficiency and increased vehicle emissions. Since vehicle engine efficiency and reducing emissions became the primary mission for most automotive manufacturers before the turn of the century, they solved a lot of these issues by inventing an electrically assisted power steering motor.
This system removed the need for power steering fluid, power steering pumps, belts, and other components that operated this system. In some instances, if a problem exists with this system, your electronic power steering system will automatically shut down to prevent damage from overheating. This is primarily seen when driving on steep slopes with lots of turns. In these instances, there is nothing wrong with the system and normal operation will resume once the temperature has reduced.
However, if there is a problem with the power steering control unitit may display a few common warning signs that will alert the driver that it may be necessary to replace this component.
Some of these symptoms include the EPS indicator light is illuminating on the dashboard, or trouble steering the vehicle. Step 1: Disconnect the vehicle's battery. Before removing any parts, locate the vehicle's battery and disconnect the positive and negative battery cables.
Step 2: Remove the steering column from the steering box.
Nissan Sentra Service Manual: C1607, C1608 EPS Control unit
Before you remove the interior dashboard or covers, make sure you can remove the steering column from the steering box first. This is often the most difficult part of the job, and you should first verify that you have the right tools and experience to complete it before you remove the other components.
To remove the steering column, you'll have to complete the following steps on most domestic and import vehicles:. Remove the engine covers and other components that block access to the steering box.
This could include the engine cover, air filter housing, and other parts. Remove any electrical connections to the steering column and steering box. Locate the steering box and steering column connection. Typically it's connected by a series of bolts two or more that have a bolt and nut ending securing them. Remove the bolts securing the two components together. Place the steering column shaft aside and proceed to the driver's compartment to remove the dashboard and steering wheel.
Step 3: Remove the steering column covers.