About the author: Leon serves as one of the leading technical editors for Mitchell 1. He is a graduate of Universal Technical Institute and has previously worked for Aamco Transmissions and as a mobile service technician. He holds 609 Certification and specializes in automotive diagnostics.
As gas prices seem to never drop to a comfortable price, it’s important for vehicles to be as fuel efficient as possible. That is where an electronic power steering (EPS) system comes in handy.
By eliminating the power steering pump which can use up to 10 hp under load, an EPS system provides up to a 2% increase in fuel economy over the conventional system. Another benefit of having an electric steering system is that it eliminates the use of hoses and fluid, therefore eliminating power steering leaks as well as a reduction in weight.
Electronic power steering systems are becoming widely popular among auto manufacturers due to the fact that they provide a more refined feel that can be adjusted as needed.
The EPS system consists of four major components: the EPS control module which collects data from the EPS components and sends out the required information; the EPS motor, its speed strength and direction controlled by the EPS Control Unit; the reduction gear, which inputs the power assist to the steering rack assembly; and torque sensor, which monitors the driver’s input and the EPS system’s mechanical output.
The EPS is powered by a permanent magnet alternating current motor and is not dependent on the engine for its power source so steering feel is not affected when the engine is shut off. The torque sensor itself has two independent coils of wire. One of the coils determines if a right hand turn is being made, the other coil determines if a left is being made. The signal is then sent from the EPS module to the appropriate coil, which will assist the vehicle in steering.
How electronic power steering works
A hybrid type of electronic power steering has been in place for some time now, but that included the use of an electric motor to drive a hydraulic pump.
The new version of EPS is all electronic. The system works by incorporating information with the EPS control unit, EPS motor, reduction gear and torque sensor.
An EPS system works by using a pinion gear assist that provides the power assist by rotating the pinion gear. The reduction gear is press fitted onto a set of splines on the pinion shaft and delivers the assist to the rack gear instead of pushing on the rack gear as in a hydraulic system.
The steering gear itself is a manual rack with an electric motor mounted on the steering column or the rack. When the driver turns the wheel, a steering sensor detects the position and rate of rotation of the steering wheel. This information along with input from a torque sensor mounted in the steering shaft is sent to the power steering control module. The system also uses other inputs from vehicle speed sensors and the traction control system which are factored in to determine how much steering assist is required. The control module then tells the motor to rotate the required amount.
Attached to the motor is the motor resolver sensor, which measures the rotation of the motor and sends the data to the EPS control module.
Different surfaces will require different amounts of steering assist. For example, a vehicle traveling on pavement will require much less steering assist than a vehicle traveling on sand or snow. With the EPS system working with other sensors, it can much more easily provide the required assistance for any kind of terrain and vehicle speed.
Electric power steering modes
• Normal mode — Left and right assist is provided in response to inputs and vehicle speed. During normal operation power assist levels will decrease as the vehicle speed increases.
• Assist limitation — Will occur if there is a problem with the information going back to the EPS control module, overheating of the EPS module or a malfunction with the controller area network.
• Assist off — System is turned off if there is a problem with any of the major EPS components.
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Diagnosis tips
The steering warning light will illuminate during the light check cycle and when the EPS is in assist off mode. The steering warning light will not illuminate during limited assist operation. By turning the steering wheel all the way to one side, it will cause the EPS system to provide the maximum amount of current to the EPS motor.
If the steering wheel is then held in this position for an extended period of time, the system will go into protection mode so the motor doesn’t overheat. If this occurs the EPS system will limit the amount of current to the motor and reduce the level of power assist. If it senses high system temperature the overload protection mode will enable. If a sensor or other another component in the EPS system fails, the self-diagnostics should detect the fault, set a code and disable power-assist. Though power steering hoses and fluid were eliminated, there are still going to be other parts that malfunction over time. Most system malfunctions present problems such as:
• Heavy steering: Check torque sensor, power steering motor, speed sensors, powers steering ECU, and ECU source voltage.
• Uneven steering between right and left: Check calibration of torque sensor (built into steering column), power steering motor, power steering ECU or wheel alignment.
• Steering effort doesn’t decrease while driving: Check torque sensor, power steering motor, power steering ECU.
• Knocking when turning steering wheel: Steering intermediate shaft, ball joint.
• Noise or vibration in steering wheel: Check power steering gear, steering column.•Squeaking – Power steering motor.
Torque sensor testing
1. Measure the resistance between torque sensor connector terminals 1 and 2, and 2 and 3.
2. If there is any malfunction, replace the steering gear and linkage.
• The torque sensor zero point should be calibrated whenever you remove and replace the steering column assembly (containing the torque sensor), power steering ECU assembly, steering wheel steering gear assembly, and if a difference is felt in steering effort between right and left.
Check steering wheel looseness, play
1. Move the steering wheel toward the shaft and in four right angle directions to inspect for looseness and play.
2. If there is any malfunction, inspect the following, and repair or replace the applicable part.
Steering wheel effort
Steering effort also varies per road conditions and type of surface the vehicle is on.
1. Verify that the equipped tire size and tire air pressure is as specified.
2. With the vehicle on a hard, level surface, put the wheels in the straight-ahead position.
3. (Check proper procedures before working on the air bag system). Remove the air bag module.
4. Start the engine and idle it.
5. Verify that the EPS warning light does not illuminate.
6. Inspect the steering wheel effort using a torque wrench. If it exceeds specifications, adjust the steering gear and, as needed, linkage.
Check steering shaft
1. Inspect the column bearing for excessive play and damage.
2. Verify that the measurement of the steering shaft is within specification. If not within the specification, replace the steering shaft component.
Specification: 508.5 mm {20.02 in}
3. Check that the tilt lever moves smoothly from the lock to the unlock position.
4. Verify that the steering shaft is fixed firmly when the tilt lever is locked.
5. If there is any malfunction, replace the steering shaft.
Check EPS motor power supply for open
1. Disconnect the battery positive terminal.
2. Inspect for continuity between EPS control module terminal and battery positive terminal.
3. Check for continuity.
Check if malfunction is caused by a bad connection of the EPS control module
1. Turn the ignition switch off.
2. Inspect connection of the EPS control module and wiring harness.
3. Disconnect the EPS control module connector.
4. Check if malfunction is caused by a bent or poorly connected EPS control module connector pin.
5. Is the connection and pin of connector and wiring harness normal?
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Vehicle-specific EPS example
Electronic power steering (EPS): 2007 Toyota Yaris. (Information provided by Toyota Motor Sales U.S.A. Inc.)
The 2007 Toyota Yaris features an electronic power steering system (EPS). This system generates steering torque (to assist power steering effort) through the operation of an electric motor and reduction gear installed on the steering column shaft.
The power steering ECU determines the direction and the amount of power-assist according to the vehicle speed signals and signals from the steering torque sensor (the torque sensor is built into the steering column assembly). As a result, steering effort is controlled to a light level during low speed driving and moderately high during high speed driving. This allows less driver effort during low speed driving, without overly sensitive power steering at higher speeds.
The power steering ECU calculates assisting power based on steering torque signals from the torque sensor and vehicle speed signals from the skid control ECU. For vehicles without ABS, the power steering ECU receives vehicle speed signals from the speedometer.
The torque sensor detects the steering effort generated when the steering wheel is turned and converts it to an electrical signal.
The EPS motor is activated by the current from the power steering ECU and generates torque to assist the steering effort.
The power steering ECU is located behind the dash, above the steering column assembly.
The steering motor assembly is located on the forward end of the steering column assembly.
The EPS fuse is located in the engine room relay box.
The main body ECU is located under the dash at the far lower left of the dashboard area. The DLC3 is located immediately under the ECU.
EPS handling precautions
Avoid any impact to ECUs and relays. If dropped or subjected to a severe impact, replace with new parts.
• Do not expose electronic parts to high heat or humidity.
• Do not touch the connector terminals, in order to prevent terminal deformation or static electricity damage.
• When the power steering ECU has been replaced with a new unit, perform the torque sensor zero point calibration.
• Avoid any impact to the steering column assembly, especially to the motor and torque sensor. If dropped or impacted, replace with new parts.
• Do not pull the wire harness when moving the steering column assembly.
• When the steering column assembly has been replaced, perform the torque sensor zero point calibration after initializing the torque sensor zero point.
NOTE: When disconnecting the connectors relating to the electronic power steering system, first center the steering wheel, then turn the ignition switch ON, then turn the ignition switch OFF, then disconnect the connectors. Do not turn the ignition switch ON when the steering wheel is not centered.
If the above operations are not performed properly, the steering center point (zero point) will deviate, which may lead to a difference in steering effort between turning right and left. If there is a difference in steering effort (left/right), perform the torque sensor zero point calibration.
Precautions for CAN communication
CAN communication lines are used to receive information from the skid control ECU (ABS ECU) and the ECM, and to transmit warnings to the combination meter. If a problem exists in the CAN communication lines, DTCs of the CAN communication line are output.
Perform troubleshooting of communication line problems when the CAN communication DTCs are output.
Be sure to start troubleshooting on the electronic power steering system after confirming that the CAN communication system is normal.
Torque sensor zero point calibration
Using the intelligent tester, perform the torque sensor zero point calibration whenever any of the following conditions occur:
• The steering column assembly (containing the torque sensor) has been replaced.
• The power steering ECU has been replaced.
• The steering wheel has been replaced.
• The steering gear assembly has been replaced.
• There is a difference in steering effort between right and left turning.
Center the steering wheel and align the front wheels straight ahead.
Connect the intelligent tester to the DLC3.
Turn the ignition switch ON and turn the tester ON. Initialize the torque sensor zero point calibration signal and perform the zero point calibration by following the prompts on the tester screen.
NOTE: Do not touch the steering wheel during the calibration process. Confirm that no DTCs are output after the zero point calibration has been completed.
If DTC C1515/15 is output, this indicates that the torque sensor zero point adjustment has not been initialized. If DTC 1516/16 is output, this indicates that torque sensor zero point adjustment is incomplete. If DTC C1534/34 is output, this indicates a malfunction of the EPS ECU.
NOTE: The torque sensor zero point calibration is performed automatically when the test mode inspection is conducted after the power steering ECU has been replaced with a new ECU. When using an intelligent tester, connect the tester to the DLC3. Turn the ignition switch ON and enter the test mode by following the prompts on the tester screen.
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Problem symptoms
Symptom: Heavy steering
Suspected area: front tires (improper inflation and/or unevenly worn), incorrect front wheel alignment, worn lower ball joint, steering gear assembly, power steering motor, battery and power source system, power source voltage of the power steering ECU or the power steering ECU.
Symptom: Steering effort differs between right and left turns
Suspected area: Steering center point (zero point) not recorded completely, front tires (improper inflation or unevenly worn), incorrect front wheel alignment, worn lower ball joint, steering gear assembly, torque sensor in steering column, steering column assembly, power steering motor, power steering ECU.
Symptom: While driving, steering effort does not change in accordance with vehicle speed or steering wheel does not return properly.
Suspected area: Lower ball joint, speed sensor (w/ABS), skid control ECU (ABS ECU), combination meter (w/o ABS), torque sensor in steering column, power steering motor, power steering ECU, controlling CAN communication system.
Symptom: Friction occurs when turning steering wheel during low speed driving.
Suspected area: Power steering motor, steering column assembly.
Symptom: High-pitched squeaking sound occurs when turning steering wheel slowly with vehicle stopped.
Suspected area: Power steering motor.
Symptom: Steering wheel vibrates and noise occurs when turning steering wheel with vehicle stopped.
Suspected area: Power steering motor, steering column assembly.
Symptom: Power steering warning (P/S warning) always indicated on the combination meter.
Suspected area: Power source voltage of power steering ECU, combination meter, power steering ECU. NOTE: See Diagnostic Trouble Codes on page 17.
Fail-safe operation
When a problem occurs in the EPS, the P/S warning light on the combination meter illuminates and, depending on the problem detected, the EPS ECU stops the power steering assist, maintains the amount of power assist constant, or reduces the amount of power assist in order to protect the system.
The amount of power assist may be decreased to prevent the EPS motor and ECU from overheating if the steering wheel is continuously turned when the vehicle is either stopped or driven at a low speed, or if the steering wheel is kept at either full-lock position for an extended time. In such cases, the amount of power steering assist returns to normal if the steering wheel is not turned for approximately 10 minutes with the engine idling.
Malfunction: Torque sensor (DTC C1511/11, C1512/12, C1513/13 and C1514/14)
Fail-safe: Assist force is restricted.
Malfunction: Torque sensor (DTC C1517/17)
Fail-safe: Power assist is stopped.
Malfunction: Motor (DTC C1524/24)
Fail-safe: Power assist is stopped.
Malfunction: Power steering ECU (DTC C1531/31, C1532/32)
Fail-safe: Power assist is stopped.
Malfunction: Temperature sensor in power steering ECU (DTC C1533/33)
Fail-safe: Assist force restricted.
Malfunction: EEPROM abnormal (DTC C1534/34)
Fail-safe: The assist force has been restricted.
Malfunction: Steering wheel location data error (DTC C1535/35)
Fail-safe: Power assist stopped.
Malfunction: Speed sensor (DTC C1541/41, C1542/42)
Fail-safe: The amount of power assist remains constant at a speed of 43 mph.
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Malfunction: IG power source voltage error (DTC C1551/51)
Fail-safe: Assist force restricted.
Malfunction: PIG power source voltage error (DTC C1552/52)
Fail-safe: Assist force restricted.
Malfunction: Over-voltage at IG and PIG terminals.
Fail-safe: Assist force restricted.
Malfunction: Power source relay (DTC C1554/54)
Fail-safe: Power assist stopped.
Malfunction: Motor relay (DTC C1555/55)
Fail-safe: Power assist stopped.
Malfunction: ECM communication error (DTC U0105)
Fail-safe: Amount of power assist remains constant at a speed of 43 mph.
Malfunction: ABS ECU communication error (DTC U0121)
Fail-safe: Amount of power assist remains constant at a speed of 43 mph.
Malfunction: High temperature in EPS ECU
Fail-safe: Assist force restricted until ECU temperature is normal.
Malfunction: Power source voltage drop
Fail-safe: Assist force suspended until voltage recovers. ●
Diagnostic trouble codes
DTC C1511/11
Detection item: Torque sensor 1 malfunction
Trouble areas: Steering column assembly (torque sensor), power steering ECU
DTC C1512/12
Detection item: Torque sensor circuit malfunction
Trouble areas: Steering column assembly (torque sensor), power steering ECU
DTC C1513/13
Detection item: Torque sensor circuit malfunction
Trouble areas: Steering column assembly (torque sensor), power steering ECU
DTC C1514/14
Detection item: Torque sensor power source circuit malfunction
Trouble areas: Steering column assembly (torque sensor), power steering ECU
DTC C1515/15
Detection item: Torque sensor zero point adjustment is not initialized
Trouble areas: Torque sensor zero point calibration not performed; steering column assembly.
DTC C1516/16
Detection item: Torque sensor zero point adjustment incomplete
Trouble areas: Torque sensor zero point calibration failure, steering column assembly
DTC C1517/17
Detection item: Torque sensor hold malfunction
Trouble areas: Steering column assembly (torque sensor), power steering ECU
DTC C1524/24
Detection item: Motor circuit malfunction
Trouble areas: Steering column assembly, power steering ECU
DTC C1531/31
Detection item: EPS ECU circuit malfunction
Trouble areas: Power steering ECU
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DTC C1532/32
Detection item: EPS ECU circuit malfunction
Trouble areas: Power steering ECU
DTC C1533/33
Detection item: EPS ECU circuit malfunction
Trouble areas: Power steering ECU
DTC C1534/34
Detection item: EPS ECU circuit malfunction
Trouble areas: Power steering ECU
DTC C1535/35
Detection item: Steering wheel location data error
Trouble areas: Power steering ECU
DTC C1541/41 (w/o ABS)
Detection item: Speed sensor malfunction
Trouble areas: Speed sensor, speed sensor circuit, combination meter, power steering ECU
DTC C1542/42 (w/o ABS)
Detection item: Speed sensor malfunction
Trouble areas: Speed sensor, speed sensor circuit, combination jeter, power steering ECU
DTC C1551/51
Detection item: IG power source circuit malfunction
Trouble areas: ECU-IG fuse, IG power source circuit, power steering ECU
DTC C1552/52
Detection item: PIG power source circuit
Trouble areas: EPS fuse, PIG power source circuit, power steering ECU
DTC C1553/53
Detection item: When resetting voltage, vehicle is being driven
Trouble areas: IG and PIG power source circuit, power steering ECU
DTC C1554/54
Detection item:EPS relay circuit
Trouble areas: EPS fuse, PIG power source circuit, power steering ECU
DTC C1555/55
Detection item: EPS motor relay circuit
Trouble areas: Power steering ECU
DTC C1571/71 (w/o ABS)
Detection item:Speed sensor malfunction (test mode DTC)
Trouble areas: Speed sensor, speed sensor circuit, combination meter, power steering ECU. In test mode, this indicates a vehicle speed check. The code may be cleared by driving the vehicle at a speed of 6 mph or more. Trouble areas can include the speed sensor, combination meter, power steering ECU or wire harness and connector
DTC C1581/81
Detection item: Assist map — un-writing
Trouble areas: Power steering ECU
DTC U0073
Detection item: Control module communication bus off
Trouble areas: CAN communication system
DTC U0105
Detection item: Lost communication with ECM
Trouble areas: CAN communication system, ECM
DTC U0121 (with ABS)
Detection item:Lost communication with anti-lock brake system (ABS) control module
Trouble areas: CAN communication system, ABS ECU
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Data active list
With the intelligent tester connected to the DLC3, turn the ignition switch ON and turn the tester ON. Operate the intelligent tester according to the screen prompts and select DATA LIST. This allows you to check active values against reference values.
Item: TRQ1 (Torque sensor 1 output value...min. 0 V, max. 5 V)
Inspection condition:
1. Steering wheel not turned (without load). Reference value 2.3 to 2.7 V
2. Steering wheel turned to the right with vehicle stopped. Reference value 2.5 to 4.7 V
3. Steering wheel turned to the left with vehicle stopped. Reference value 0.3 to 2.5 V
Item: TRQ2 (Torque sensor 2 output value...min. 0 V, max. 5 V)
Inspection condition:
1. Steering wheel not turned (without load). Reference value 2.3 to 2.7 V
2. Steering wheel turned to right with vehicle stopped. Reference value 2.5 to 4.7 V
3. Steering wheel turned to left with vehicle stopped. Reference value 0.3 to 2.5 V
Item: TRQ3 (Torque value for assist control....min. 0 V, max. 5 V)
Inspection condition:
1. Steering wheel not turned (without load). Reference value 2.3 to 2.7 V
2. Steering wheel turned to right with vehicle stopped. Reference value 2.5 to 4.7V
3. Steering wheel turned to left with vehicle stopped. Reference value 0.3 to 2.5 V
Item: SPD (Vehicle speed from meter...min. 0 mph, max. 158.8 mph)
Inspection condition:
1. Vehicle stopped. Reference value 0 mph
2. Vehicle driven at a constant speed. Reference value...no significant fluctuation
Item: MOTOR ACTUAL (Current to motor...min. – 128 A, max. 127 A)
Item: COMMAND VALUE (Requested current to motor min. – 128 A, max. 127 A)
Item: THERMISTOR TEMP (ECU substrate temperature min. – 122 deg F, max. 401 deg F)
Inspection condition: Ignition switch ON
Item: PIG SUPPLY (Power source voltage to activate motor...min. 0 V, max. 25.5 V)
Inspection condition: Power steering in operation. Reference value 11 to 14 V
Item: IG SUPPLY (ECU power source voltage...min. 0 V, max. 25.5 V)
Inspection condition: Reference value 11 to 14 V
Item: TRQ1 ZERO VAL (Zero point value of torque sensor 1...min. 0 V, max. 5 V)
Inspection condition: Steering wheel not turned (without load)
Reference value 2.3 to 2.7 V
Item: TRQ2 ZERO VAL (Zero point value of torque sensor 2...min. 0 V, max. 5 V)
Inspection condition: Steering wheel not turned (without load)
Reference value 2.3 to 2.7 V
Item: TRQ3 ZERO VAL (Zero point value of torque sensor for assist control....min. 0 V, max. 5 V)
Inspection condition: Steering wheel not turned (without load)
Reference value 2.3 to 2.7 V
Item: MOTOR TERMINAL (+) (Motor terminal M1 voltage...min. 0 V, max. 25.5 V)
Inspection condition:
1. Steering wheel turned to right. Reference value below 1 V
2. Steering wheel turned to left. Reference value 11 to 14 V
Item: MOTOR TERMINAL (-) (Motor terminal M2 voltage...min. 0 V, max. 25.5 V)
Inspection condition:
1. Steering wheel turned to right. Reference value 11 to 14 V
2. Steering wheel turned to left. Reference value below 1 V
Item: MTR OVERHEAT
Continuous overheat prevention control record: REC/UNREC
Item: MTR LOW POWER
PIG power source voltage drop record: REC/UNREC
Item: CONTROL MODE
Codes indicating DTC detection timing during ECU control displayed in hexadecimal
Item: IG ON/OFF TIMES
Number of times ignition switch turned on after DTC detection: min. 0 time, max. 255 times
Item: # CODE
Number of detected DTCs when freeze frame data stored: min. 0 time, max. 255 times
Item: ECU ID
ECU identification information
Item: TEST MODE STAT
Selected mode: Normal Mode/Test Mode
FAQs
What is an electronic power steering? ›
The electric power steering uses an electric motor that draws energy from the vehicle's electrical system to provide steering assistance. Sensors detect the torque or effort that the driver is applying at the steering wheel, and a computer decides how much assist needs to be added.
What happens when electronic power steering goes out? ›When that happens, your car's steering system will revert to manual operation (i.e., your muscles do all the work). As a result, the steering wheel will become very difficult to turn. Electric power steering can stop working suddenly and render the vehicle very difficult to drive as well.
Does electronic power steering have fluid? ›Electric power steering systems are simple. Hydraulic power steering systems tend to be heavier than electrical systems. Hydraulic power steering systems require hydraulic fluid, which must be changed from time to time. Electrical systems don't use any fluid, so you don't have to do as much maintenance.
Is electronic power steering better? ›Electric power steering provides better fuel economy
This method reduces the amount of weight in the vehicle. Also, the EPS system doesn't use power from the engine as the hydraulic systems do. Overall, the electric power steering system is more efficient.
However, the good news is driving without electric power steering should not damage your car. If your power steering fails, you can still operate the steering wheel—at least enough to make it to the side of the road.
Can you still drive if electric power steering goes out? ›When the power steering stops working, you should refrain from operating the vehicle until the pump is replaced.
What is a common causes of electric power steering failure? ›Today's electronic power steering systems may fail due to issues with the mounted electric motor. In particular, excessive heat on the motor is likely to cause the failure modes. Infiltration of the system environment by water, dirt, or other contaminants will also likely lead to EPS failure.
How much does it cost to fix electric power steering? ›The average cost for power steering control module replacement is between $876 and $906. Labor costs are estimated between $116 and $146 while parts are priced at $760. This range does not include taxes and fees, and does not factor in your specific vehicle or unique location. Related repairs may also be needed.
How do I reset my electronic power steering? ›All you need to do is turn off your engine, then restart it so the light can reset. In most cases, it should come back on, and this only indicates that it may have thought it suspected a problem due to a mistake in the computer system.
How long does electronic power steering last? ›There is no set lifespan for your car's power steering control unit. In most instances, it should last for the life of the vehicle. However, electronics are subject to unanticipated failures.
How long do electric power steering pumps last? ›
Frequency of Replacement
Most vehicle components have an expected lifespan, and power steering pumps are no different. A pump typically lasts up to 100,000 miles or better before experiencing any significant issues.
Electrical charge is used to rotate the motor and through energy transfer, a lateral force is produced that aids the movement along the steering rack. The main argument against eletronics is steering feel.
Which type of steering is best? ›The electric power steering is more efficient and works to the point.
Do electric power steering pumps run all the time? ›One drawback to the system is the amount of wasted energy. The pump runs all the time, even when the car doesn't need steering assistance while moving on a straight stretch of road.
How do I know if my electric power steering is failing? ›- Whining Noise When You Turn the Wheel. ...
- Slow Responding or Stiff Steering Wheel. ...
- Squealing Noise Upon Starting Your Vehicle. ...
- Reddish Puddle Underneath Your Car.
You can stop the engine and then start it again – the EPS will recover for a while, but this is temporary. The soonest possible diagnostics and repair in order to restore EPS normal function is highly recommended.
How do you know if your electric power steering is going out? ›Difficulty turning the wheel
One of the most common signs you have steering wheel failure is that it is hard to turn the steering wheel. In most cases, this is usually caused by a lack of power steering fluid or a leak in the system. It could also mean that you have a worn-out power steering pump that needs replacing.
To fix the steering angle sensor, you need to recalibrate it to send accurate data to the electric control unit (ECU). Once recalibrated, the ECU will start providing the required amount of assistive torque and speed.
Why is my electric power steering hard to turn? ›Electric steering — stiff steering on one side only
If electric steering is stiff only in one direction the usual cause is that the steering system is out of calibration and the usually fix is recalibrating it with the scan tool. Yes, this one really is that simple.
Another disadvantage of electric power steering is that it cannot easily be fixed with standard parts and labor like a hydraulic system. EPS systems may require specialized equipment and knowledge to diagnose and repair electrical issues that may be caused by a faulty onboard computer or various sensors.
What happens if power steering fails while driving? ›
When the power steering fails, the wheels of the car become exponentially more difficult to turn. The wheels will turn, but the force required to make this happen can be unexpected and problematic. If power steering failure occurs while a car is in motion, an accident can result.
How do I fix the EPS problem in my car? ›This issue with the EPS light can also be caused if you have recently had to jump-start your car, or you've disconnected the battery. Occasionally, the problem can be fixed by simply turning your vehicle off and on again.
Where is the electric power steering fuse? ›The fuse panel is located under the instrument panel to the left of the steering column.
Can EPS cause car not to start? ›Technically yes, it is possible for the electric power steering to prevent the car from starting. Unlike a hydraulic power steering system, the electric power steering gets its charge from the battery, and if it drains too much power from your battery, your car may not start.
What percentage of cars have electric power steering? ›Currently, more than 30% of the passenger cars are running with EPS technology in India, and the technology is likely to be implemented in the majority of the budget passenger cars during the forecast period.
What are the two types of electric power steering? ›There are four forms of EPS based on the position of the assist motor. They are the column assist type (C-EPS), the pinion assist type (P-EPS), the direct drive type (D-EPS) and the rack assist type (R-EPS).
Can electric power steering overheat? ›Abstract. The EPS motor will be over-heated if large current lasts for a long time, which will decline the performance of EPS motor and even lead to irreparable damage. So the over-temperature protection control should be conducted in order to protect the components of EPS system, especially the durability of EPS motor ...
Can electric power steering squeal? ›When the power steering pump starts to die, it will let you know by making squealing sounds or low groaning noises when you turn the steering wheel.
Does water affect electric power steering? ›JBA - The risk that often occurs when a car is flooded is damage to some parts of the engine or some electrical compound. One of them is an electrical component called the Electric Power Steering (EPS). This electrical component can be damaged by floods that hit EPS modules and motors.
What type of fluid is used in an electric power steering system? ›Automatic transmission fluid (ATF) is the same fluid used inside the automatic transmission. ATF can also be used in some power steering systems. Some ATF types include Dexron and Mercon. Synthetic power steering fluid is a non-oil-based fluid that's created in a lab.
How do you calibrate electric power steering? ›
The calibration process is normally done by putting the wheels in the straight forward position, and then zeroing out the sensor with a scan tool. Being informed on these systems is important to a complete, safe, and quality repair.
Do all new cars have electric power steering? ›Electric power steering (EPS) is the norm on today's new cars. There's still a solid metal steering shaft running from the steering wheel to the steering rack, which steers the tires, but the rest is high-tech.
Why is hydraulic steering better than electric? ›Hydraulic power steering extracts power from engine, so it reduces the fuel mileage of the engine. Electric power steering consumes power from battery which is also charged by engine, but it consumes less power compared to Hydraulic power steering.
Where is the EPS steering sensor located? ›The sensor sits on the steering pinion. A pole wheel is fitted on the input shaft, which is connected to the steering pinion by means of the torsion bar.
What are the 3 types of steering? ›There are three basic types of power steering systems found in vehicles: the hydraulic power steering (HPS), the electric power hydraulic steering (EPHS), and the fully electric power steering (EPS). Electric and electronic power steering both refer to the same system.
Which car has the smoothest steering? ›- Aston Martin One-77.
- Audi R8.
- Bentley Continental GT SuperSports.
- BMW M3.
- Ferrari 458 Italia.
- Lamborghini LP670-4 Superveloce.
- Lexus LFA.
- Mercedes-Benz SLS.
Both hands should be placed outside of the steering wheel on opposite sides. Your grip should be firm, yet gentle. Use your fingers instead of the palms of your hands and keep your thumbs up along the face of the steering wheel. Never turn the wheel while gripping it from the inside of its rim.
What is the difference between power steering and electronic steering? ›There are mainly two types of power steering available - Electric and Hydraulic. The Electric power steering simply uses a electric motor to direct the steering commands made by the driver easily whereas, a Hydraulic power steering uses pumps and piston for the same.
How much does it cost to replace electric power steering? ›The average cost for power steering control module replacement is between $876 and $906. Labor costs are estimated between $116 and $146 while parts are priced at $760. This range does not include taxes and fees, and does not factor in your specific vehicle or unique location. Related repairs may also be needed.
Which type of steering system is better? ›Hydraulic power steering is a primitive technology used for decades and has improved a lot with time. Earlier, it did not have any difference in steering response with speed of the car, but the new age of hydraulic power steering are speed sensitive and work better than the older hydraulic power steering.
Why do modern cars use electronic steering system? ›
Hydraulic or electric actuators add controlled energy to the steering mechanism, so the driver can provide less effort to turn the steered wheels when driving at typical speeds, and reduce considerably the physical effort necessary to turn the wheels when a vehicle is stopped or moving slowly.
How is electric power steering diagnosed? ›The main indication you'll get if there is a malfunction with the electric power steering system is that the EPS light will illuminate on the dashboard. Specifically, the warning light will come on when the EPS system is off.
How do I reset my electric power steering? ›All you need to do is turn off your engine, then restart it so the light can reset. In most cases, it should come back on, and this only indicates that it may have thought it suspected a problem due to a mistake in the computer system.
What causes EPS problems? ›EPS outage can be caused by a car battery, an alternator or a circuit fault. Regular checkup should be provided for all those car elements.