General Description
The ABS ECU (Electronic Control Unit) monitors the system (battery) voltage. The normal system voltage range is essential for controlling the ABS system as intended.
DTC Description
When the voltage is higher than the expected normal value, this code is set, and the ABS/EBD/ESC/DBC functions are prohibited.
If the voltage recovers to within normal operating range, then the controller returns to normal operation as well.
The ABS ECU (Electronic Control Unit) monitors the system (battery) voltage. The normal system voltage range is essential for controlling the ABS system as intended.
When the voltage is lower than the expected normal value, this code is set.
If the voltage recovers, to within normal operating range, then the controller returns to normal operations as well.
The HECU supplies operating voltage to the Steering Angle Senor (12V), Yaw rate & Lateral G sensor (12V), and the G sensor (5V).
The HECU monitors the supply voltage to each sensor.
If supply voltage is out of specified range ABS/ESC warning lamps are turned on and ABS/ESC controls are inhibited.
A failure is detected if the voltage supplied to each sensor is outside the specified range for more than the specified minimum fault duration.
The Wheel Speed Sensors (WSS) are an essential component the ABS system. The WSS signals are used to calculate vehicle speed and to determine whether wheel lock occurs.
The Wheel Speed Sensors are active hall-sensor type.
If the sensor signal is out of the specified range for 140msec, the HECU determines that the circuit is open/short, and sets this code.
The Wheel Speed Sensors (WSS) are an essential component the ABS system. The WSS signals are used to calculate vehicle speed and to determine whether wheel lock occurs.
The Wheel Speed Sensors are active hall-sensor type.
The ABS ECU monitors the wheel speed sensor signal continuously.
This code is set if an abnormal speed change ratio is detected while the vehicle speed is more than 2 Km/h.
Warning lamp is turned OFF unless additional faults are detected when the IG KEY is turned ON again, and wheel speed is more than 10 Km/h.
The Wheel Speed Sensors (WSS) are an essential component the ABS system. The WSS signals are used to calculate vehicle speed and to determine whether wheel lock occurs.
The Wheel Speed Sensors are active hall-sensor type.
The ABS ECU monitors the wheel speed sensor signal continuously.
This code is set when the sensor air gap is out of specified range or when the ABS control cycle is continued abnormally.
The HECU checks for air gap malfunctioning by monitoring the sensor signal at speeds between 2 Km/h to 10 Km/h.
Warning lamp is turned OFF unless additional faults are detected when the IG KEY is turned ON again, and wheel speed is more than 10 Km/h (6.2 mph).
The Wheel Speed Sensors (WSS) are an essential component the ABS system. The WSS signals are used to calculate vehicle speed and to determine whether wheel lock occurs.
The Wheel Speed Sensors are active hall-sensor type.
If the sensor signal is out of the specified range for 140msec, the HECU determines that the circuit is open/short, and sets this code.
The Wheel Speed Sensors (WSS) are an essential component the ABS system. The WSS signals are used to calculate vehicle speed and to determine whether wheel lock occurs.
The Wheel Speed Sensors are active hall-sensor type.
If the sensor signal is out of the specified range for 140msec, the HECU determines that the circuit is open/short, and sets this code.
The Wheel Speed Sensors (WSS) are an essential component the ABS system. The WSS signals are used to calculate vehicle speed and to determine whether wheel lock occurs.
The Wheel Speed Sensors are active hall-sensor type.
The ABS ECU monitors the wheel speed sensor signal continuously.
This code is set if an abnormal speed change ratio is detected while the vehicle speed is more than 2 Km/h.
Warning lamp is turned OFF unless additional faults are detected when the IG KEY is turned ON again, and wheel speed is more than 10 Km/h.
The Wheel Speed Sensors (WSS) are an essential component the ABS system. The WSS signals are used to calculate vehicle speed and to determine whether wheel lock occurs.
The Wheel Speed Sensors are active hall-sensor type.
The ABS ECU monitors the wheel speed sensor signal continuously.
This code is set when the sensor air gap is out of specified range or when the ABS control cycle is continued abnormally. The HECU checks for air gap malfunctioning by monitoring the sensor signal at speeds between 2 Km/h to 10 Km/h.
Warning lamp is turned OFF unless additional faults are detected when the IG KEY is turned ON again, and wheel speed is more than 10 Km/h (6.2 mph).
The Wheel Speed Sensors (WSS) are an essential component the ABS system. The WSS signals are used to calculate vehicle speed and to determine whether wheel lock occurs.
The Wheel Speed Sensors are active hall-sensor type.
If the sensor signal is out of the specified range for 140msec, the HECU determines that the circuit is open/short, and sets this code.
The Wheel Speed Sensors (WSS) are an essential component the ABS system. The WSS signals are used to calculate vehicle speed and to determine whether wheel lock occurs.
The Wheel Speed Sensors are active hall-sensor type.
The ABS ECU monitors the wheel speed sensor signal continuously.
This code is set if an abnormal speed change ratio is detected while the vehicle speed is more than 2 Km/h.
Warning lamp is turned OFF unless additional faults are detected when the IG KEY is turned ON again, and wheel speed is more than 10 Km/h.
The Wheel Speed Sensors (WSS) are an essential component the ABS system. The WSS signals are used to calculate vehicle speed and to determine whether wheel lock occurs.
The Wheel Speed Sensors are active hall-sensor type.
The ABS ECU monitors the wheel speed sensor signal continuously.
This code is set when the sensor air gap is out of specified range or when the ABS control cycle is continued abnormally.
The HECU checks for air gap malfunctioning by monitoring the sensor signal at speeds between 2 Km/h to 10 Km/h.
Warning lamp is turned OFF unless additional faults are detected when the IG KEY is turned ON again, and wheel speed is more than 10 Km/h (6.2 mph).
The Wheel Speed Sensors (WSS) are an essential component the ABS system. The WSS signals are used to calculate vehicle speed and to determine whether wheel lock occurs.
The Wheel Speed Sensors are active hall-sensor type.
The ABS ECU monitors the wheel speed sensor signal continuously.
This code is set if an abnormal speed change ratio is detected while the vehicle speed is more than 2 Km/h.
Warning lamp is turned OFF unless additional faults are detected when the IG KEY is turned ON again, and wheel speed is more than 10 Km/h.
The Wheel Speed Sensors (WSS) are an essential component the ABS system. The WSS signals are used to calculate vehicle speed and to determine whether wheel lock occurs.
The Wheel Speed Sensors are active hall-sensor type.
The ABS ECU monitors the wheel speed sensor signal continuously.
This code is set when the sensor air gap is out of specified range or when the ABS control cycle is continued abnormally.
The HECU checks for air gap malfunctioning by monitoring the sensor signal at speeds between 2 Km/h to 10 Km/h. Warning lamp is turned OFF unless additional faults are detected when the IG KEY is turned ON again, and wheel speed is more than 10 Km/h (6.2 mph).
The pressure sensor, installed in the HECU, converts the brake pressure to judge the driver's brake intention when the ESC program is operated. When pressure is applied to the sensor, the resistance of the sensor's strain gauge changes. The change in resistance changes the voltage output from the sensor.
A failure is detected if the output signal voltage of the pressure sensor is out of specified range.
The pressure sensor, installed in the HECU, converts the brake pressure to judge the driver's brake intention when the ESC program is operated. When pressure is applied to the sensor, the resistance of the sensor's strain gauge changes. The change in resistance changes the voltage output from the sensor.
The failure is detected if the pressure sensor signal noise is out of normal range, or the pressure sensor signal is changed abnormally.
In spite of no brake switch signal, master cylinder pressure exceeds 20bar when brake switch is normal.
The Steering angle sensor (SAS) is installed in MDPS assembly.
The SAS is used to determine turning direction and speed of the steering wheel.
The HECU uses the signals from the SAS when performing ESC-related calculations.
The HECU monitors the signals of the steering angle sensor and if the abnormal signal is detected or the difference between the angle speed calculated from the other sensors and the angle speed measured from the steering angle sensor is above a certain value, this DTC is set.
In case of EPS equipped vehicle, the Steering angle sensor (SAS) is installed in MDPS assembly.
The SAS is used to determine turning direction and speed of the steering wheel.
The HECU uses the signals from the SAS when performing ESC-related calculations.
The steering angle sensor in the ESC system is an absolute angle sensor type. For this reason, the steering angle sensor needs the zero setting (Calibration) by the scantool. If the calibration of this sensor is undone, this DTC is set.
When the vehicle is turning, the yaw rate sensor detects the yaw rate electronically by the vibration change of plate fork inside the yaw rate sensor. If the yaw velocity reaches the specific velocity after it detects the vehicle's yawing, the ESC control is reactivated. The lateral G sensor senses the vehicle's lateral acceleration. A small element inside the sensor is attached to a deflectable leverarm by lateral acceleration. Direction and magnitude of lateral acceleration loaded to vehicle can be known by electrostatic capacity changing according to lateral acceleration. It interchanges signals with HECU through extra CAN line which is only used for communication between HECU and the sensor. In case of the vehicle with 4WD & ESC, G sensor is packaged with yaw rate & later G sensor.
A failure is detected if the Yaw rate & lateral G & longitudinal G sensor's message was not received or the HECU detects the sensor CAN Bus off state for more than the specified failure detection time. The Monitoring starts after Power-Up.
When the vehicle is turning, the yaw rate sensor detects the yaw rate electronically by the vibration change of plate fork inside the yaw rate sensor. If the yaw velocity reaches the specific velocity after it detects the vehicle's yawing, the ESC control is reactivated. The lateral G sensor senses the vehicle's lateral acceleration. A small element inside the sensor is attached to a deflectable leverarm by lateral acceleration. Direction and magnitude of lateral acceleration loaded to vehicle can be known by electrostatic capacity changing according to lateral acceleration. It interchanges signals with HECU through extra CAN line which is only used for communication between HECU and the sensor. In case of the vehicle with 4WD & ESC, G sensor is packaged with yaw rate & later G sensor.
If the difference between the estimated value from the other sensors and the measured value from the yaw rate and lateral G sensor is larger than predefined value for predefined time, the failure is recognized.
The longitudinal G sensor is installed in the YAW-RATE sensor.
This longitudinal G sensor detects vertical acceleration of the vehicle, while the lateral G sensor detects lateral acceleration of the vehicle. The HECU uses these signals for the Hill start Assist Control function.
If abnormal zero-setting is detected or no information in the HECU is detected, a failure is recognized.
The EPB system is the shorten word of Electric Parking Brake system. This system is the parking brake device which is used instead of the conventional hand-break system. When a driver presses the EPB button, the button signal is delivered to the EPB ECU and then the EPB actuator which consists of a motor and a gears is activated. At this time, while the motor in the EPB actuator rotates, the motor pulls the EPB cable connected to the rear wheels. The HECU exchanges signals with the EPB ECU for a normal control through CAN communication.
Driver can inhibit the AVH control by AVH switch.
When switch signal sends into the HECU, the AVH control is stopped and if the next switch signal is inputted again, the AVH control is ready.
This DTC is set when the condition that the level of AVH switch is high is continued for more than 60 seconds.
Driver can inhibit the ESC control by ESC switch.
When switch signal sends into the HECU, the ESC warning lamp goes "ON" and the ESC control is stopped and if the next switch signal is inputted again, the ESC control is ready. This function is used for sporty driving or vehicle inspection.
This DTC is set when the condition that the level of ESC switch is high is continued for more than 60 seconds.
This switch is mounted on the pedal assembly and is used to send the status of the brake pedal to the HECU. There are two separate switches in the switch housing. The Brake Switch is normally closed while the Brake Light Switch is normally open.
The HECU checks for open or shorted circuits of the brake switch.
If an error is present, the warning lamp will illuminate.
The clutch switch is used for the Hill start Assist Control function.
If a clutch signal failure continues for a given time, a failure is recognized.
The clutch switch is used for the Hill start Assist Control function.
If the wrong reverse gear signal has been set for a certain period of time, a failure is recognized.
(A/T) HECU receives reverse gear switch signal from TCM via C-CAN.
(M/T) Cluster receives back up lamp signal from IPS (Intelligent Power Switch System) via B-CAN and sends it to HECU via C-CAN.
The HECU consists of an ECU (Electronic Control Unit) and a HCU (Hydraulic Control Unit).
The HCU portion of the assembly contains a pump motor, solenoid valves, and accumulator.
The function of the HCU is to increase, decrease or maintain the hydraulic pressure supplied to a wheel by operating the return pump according to HECU control signal while ABS control is active.
The ECU monitors various sensor and switch inputs.
These inputs are used to make decisions regarding HCU component operation.
The HECU monitors the operation of the IC components such as memory, register, A/D converter and so on.
The ECU sets this code when the EEPROM data read by the master processor is different than prior data, or when the processor detects abnormal operation in RAM, Status Register, Interrupt, Timer, A/D converter or cycle time.
The HECU sends requirement data, such as torque reduction, the number of fuel cut cylinders, and the ESC control request, to the PCM (ECM & TCM) through CAN bus line. The PCM (ECM) performs the fuel cut function according to a request signal from the HECU and then retards an ignition timing. The PCM (TCM) maintains current gear position during the ESC control period in order not to increase power which causes a Kickdown shift.
The HECU checks the CAN RAM for normal TCS control, and sets this code if a CAN RAM malfunction is detected.
The HECU sends requirement data, such as torque reduction, the number of fuel cut cylinders, and the ESC control request, to the PCM (ECM & TCM) through CAN bus line. The PCM (ECM) performs the fuel cut function according to a request signal from the HECU and then retards an ignition timing. The PCM (TCM) maintains current gear position during the ESC control period in order not to increase power which causes a Kickdown shift.
The HECU checks the CAN communication lines for normal ESC control, and sets this code if an ECM message is not received within 500ms.
The HECU sends requirement data, such as torque reduction, the number of fuel cut cylinders, and the ESC control request, to the PCM (ECM & TCM) through CAN bus line. The PCM (ECM) performs the fuel cut function according to a request signal from the HECU and then retards an ignition timing. The PCM (TCM) maintains current gear position during the ESC control period in order not to increase power which causes a Kickdown shift.
The HECU checks the CAN communication lines for the normal ESC control, and sets this code if an TCM message is not received within 500ms.
The HECU sends requirement data, such as torque reduction, the number of fuel cut cylinders, and the ESC control request, to the PCM (ECM & TCM) through CAN bus line. The PCM (ECM) performs the fuel cut function according to a request signal from the HECU and then retards an ignition timing. The PCM (TCM) maintains current gear position during the ESC control period in order not to increase power which causes a Kickdown shift.
The HECU checks the CAN communication lines for the normal ESC control, and sets this code if the data received from EMS is not the same with that from TCM.
The HECU sends requirement data, such as torque reduction, the number of fuel cut cylinders, and the ESC control request, to the PCM (ECM & TCM) through CAN bus line. The PCM (ECM) performs the fuel cut function according to a request signal from the HECU and then retards an ignition timing. The PCM (TCM) maintains current gear position during the ESC control period in order not to increase power which causes a Kickdown shift.
The HECU checks the CAN communication lines for normal TCS control, and sets this code if CAN BUS OFF status is detected for more than 100ms.
The Steering angle sensor (SAS) is installed in MDPS assembly.
The SAS is used to determine turning direction and speed of the steering wheel.
The HECU uses the signals from the SAS when performing ESC-related calculations.
The HECU checks the CAN communication lines for normal control and if a steering anlage sensor's message is not received for a certain period, this DTC is set.
The AVH (Auto Vehicle Hold) is a convenience and comfort function which prevents vehicle from rolling away when depressing the brake pedal with 'D' position in gear after standing still until pressing an accelerator pedal.
It is operated via HECU. The HECU maintains the state of standing still with holding last applied braking pressure even though the driver depresses the brake pedal.
The HECU exchanges CAN messages with cluster, EPB ECU for normal operation of the AVH. (If the HECU receives the door open message from cluster, it prohibits the AVH operation)
The HECU checks the CAN communication lines for the normal control, and sets this code if a cluster message is not received within 2s.
The AVH (Auto Vehicle Hold) is a convenience and comfort function which prevents vehicle from rolling away when depressing the brake pedal with 'D' position in gear after standing still until pressing an accelerator pedal.
It is operated via HECU. The HECU maintains the state of standing still with holding last applied braking pressure even though the driver depresses the brake pedal.
The HECU exchanges CAN messages with cluster, EPB ECU for normal operation of the AVH. (If the HECU receives the door open message from cluster, it prohibits the AVH operation)
The HECU checks the CAN communication lines for normal control and if an EPB ECU's message is not received for a certain period, this DTC is set.
The AVH (Auto Vehicle Hold) is a convenience and comfort function which prevents vehicle from rolling away when depressing the brake pedal with 'D' position in gear after standing still until pressing an accelerator pedal.
It is operated via HECU. The HECU maintains the state of standing still with holding last applied braking pressure even though the driver depresses the brake pedal.
The HECU exchanges CAN messages with cluster, EPB ECU for normal operation of the AVH. (If the HECU receives the door open message from cluster, it prohibits the AVH operation)
The HECU monitors CAN messages for a normal operation and if the invalid messages from EPB ECU are detected, this DTC is set.
The AVH (Auto Vehicle Hold) is a convenience and comfort function which prevents vehicle from rolling away when depressing the brake pedal with 'D' position in gear after standing still until pressing an accelerator pedal.
It is operated via HECU. The HECU maintains the state of standing still with holding last applied braking pressure even though the driver depresses the brake pedal.
The HECU exchanges CAN messages with cluster, EPB ECU for normal operation of the AVH. (If the HECU receives the door open message from cluster, it prohibits the AVH operation)
The HECU monitors CAN messages for a normal operation and if the invalid messages from cluster are detected, this DTC is set.
CAN communication is a circuit that consists of a low line and a high line and two resister, one in the Cluster and one in the PCM. The CAN is used for communication with each control module (PCM, 4WD ECM, TCM, ABS).
Vehicle Stability Management (VSM) is a function to maintain optimum steering stability and braking distance while a vehicle slips. When the vehicle slips, the ESC sends required torque value to EPS ECU via the CAN line. After receiving the torque value, the EPS ECU performs steering control.
The HECU checks the CAN communication lines for the normal ESC control, and sets this code if a EPS message is not received within 500ms.
CAN communication is a circuit that consists of a low line and a high line and two resister, one in the Cluster and one in the PCM. The CAN is used for communication with each control module (PCM, 4WD ECM, TCM, ABS).
Vehicle Stability Management (VSM) is a function to maintain optimum steering stability and braking distance while a vehicle slips. When the vehicle slips, the ESC sends required torque value to EPS ECU via the CAN line. After receiving the torque value, the EPS ECU performs steering control.
The HECU checks the CAN communication lines and sets this code if an abnormal EPS message is received.
The Electronic Stability Control (ESC) system recognizes a critical driving condition with the Yaw-rate sensor, Lateral acceleration sensor and Steering angle sensor. The ESC stabilizes the vehicle by a individual wheel braking and engine torque control through CAN communication.
The HECU checks variant code and if an inappropriate variant code or no variant code is detected, this DTC is set.
The HECU supplies battery power to all solenoid valves with a valve relay which is controlled by the Electronic Control UNIT (ECU).
The valve relay and all solenoid valves are installed inside the HECU (Hydraulic and Electronic Control Unit).
The ESC ECU monitors the voltage from the valve relay.
When the valve relay is switched to ON, the HECU will set this code if the solenoid voltage is below a specific range for a period of time.
When the valve relay is switched to OFF, the HECU sets this code if the solenoid voltage is over a specific range for a period of time.
The Hill-start Assist Control (HAC) function helps the vehicle not to slip on a steep hill when starting up without depressing the brake pedal. When this function is operating, brake lamp turns on by the brake lamp relay for representing vehicle braking.
The HECU monitors the brake lamp relay (HAC relay) for normal operation. If there is an open or a short in the relay circuit, this DTC is set.
Some markets have an Emergency Stop Signal (ESS) function. When a vehicle is in an emergency stop condition, the brake lamp blinks to inform the vehicle behind of the emergency stop. While this function is operating, ESS brake lamp relay flashes the brake lamp.
The HECU monitors the ESS brake lamp relay (ESS) relay for normal operation. If there is an open or short in the relay circuit, this DTC is set.
The BTCS / HECU calculates the DISC temperature by looking at the Wheel speed, vehicle speed change, control mode and BLS (Brake Lamp Signal) signal.
The calculated DISC Temperature is used to protect DISC from overheating caused by over use which may cause a decrease in brake efficiency.
The HECU calculates a disc's temperature for a normal operation and if the calculated disc's temperature is over 500 °C (932 °F), this DTC is set.
The ABS HECU is composed of a ECU (Electronic Control Unit) and an HCU (Hydraulic Control Unit), so the HECU hardware includes all solenoid valves inside the unit as well as the ECU.
Solenoid valves are switched to ON, OFF by HECU when the ABS is activated. Solenoid valves function is to increase, decrease or maintain the hydraulic pressure supplied to a wheel cylinder.
The HECU monitors the operation of the valves by checking the solenoid circuit voltage and sets this code if an incorrect voltage is detected.
The ABS ECU supplies battery power to the electric motor by way of a motor relay which is controlled by the Electronic Control Unit (ECU).
The electric motor pump supplies hydraulic pressure to all wheel brake calipers by operating the piston inside the pump.
The ABS ECU monitors the pump motor relay. If the ECU detects an open or short in the motor circuit, it then sets this code.