Hyundai i20 Quiz
Body Electrical System

Description and Operation

In this manual: Body Electrical System
General Information — 17Engine Mechanical System — 79Engine Electrical System — 50Emission Control System — 22Engine/Fuel Control System — 107Clutch System — 27MANUAL TRANSMISSION SYSTEM — 21Drive Shaft and Axle — 18Suspension System — 29Steering System — 21Restraint — 41Braking System — 53Body Work (Interior and Exterior) — 190Body Electrical System — 181Heating, Ventilation and Air Conditioning — 58
23steps
~138min
4/5difficulty
Done 0 of 23

General Description, Installation

PAS (Parking Assist System) is an electronic driver assistance device. It encourages the driver to be cautious when parking or driving slowly after detecting an object at the side and rear of the vehicle using ultrasonic waves. PAS includes four PS sensors that detect obstacles and transmit the result, divided into three alert levels (first, second and third), to the BCM via the communication line. The BCM determines the alert level based on the communication message transmitted from the slave sensors, then activates the buzzer sound or transmits data for display.
System Operation Specification
  1. INITIAL Mode
    1. System initialization time is 500 ms after ALL1 ON with the shift lever in R.
    2. The PAS recognizes the COVER and sets the sensor ID during initialization.
    3. The PAS activates each sensor, then performs diagnosis once. BCM initialization is complete.
    4. The PAS start buzzer operates normally when the sensor does not send an error message, and at the end of error diagnosis.
    5. If an error is received from the sensors, the PAS start buzzer does not operate, but the malfunction signal is output for a certain time. If there is a display option, the warning signal is also shown above.
    6. The buzzer sounds once when a sensor malfunctions, but the display remains illuminated continuously until the malfunction is fully repaired.
  2. NORMAL MODE
    1. LIN communication starts and is maintained after ALL1 ON with the shift lever in R.
    2. The BCM sends a request message to each sensor to check the initial system status, and the four sensors respond in time. At this time, if there are no problems, the alarm starts 500 ms after the shift lever is moved to R, at 300 ms intervals.
    3. After initialization, normal mode starts 100 ms after the end of the alarm output.
    4. The obstacle alarm is divided into 3 levels. The first and second levels sound intermittently, and the third level sounds continuously.
    5. For display, data from each sensor is sent from the BCM to the display, such as the instrument cluster. CAN communication is used for transmission, and the maximum gate time is 50 ms.
    6. The effective vehicle speed for PAS operation is less than 10 km/h.
    7. Refer to the "Digital PAS Project LIN Communication" section for more detailed communication specifications.
  3. SETUP MODE
    1. Normally, the initial condition is the same as NORMAL MODE. Use the SETUP TOOL as the master tool instead of the BCM MASTER TOOL.
    2. Therefore, the BCM is not connected to the LIN BUS.
    3. The SETUP TOOL displays the analog path after obtaining the initial data in LIN diagnostic base format by communicating with the sensors.
    4. Refer to the "Digital PAS Project LIN Communication" section for more detailed communication specifications.
  4. TUNING MODE
    1. The role of SETUP MODE is as follows.
      • Check the assigned ID for each sensor
      • Check the variant ID for each sensor.
    2. Normally, the initial condition is the same as NORMAL MODE. Use the SETUP TOOL as the master tool instead of the BCM MASTER TOOL.
    3. Therefore, the BCM is not connected to the LIN BUS.
    4. The SETUP TOOL checks and assigns the supplier ID and function ID.
    5. Refer to the "Digital PAS Project LIN Communication" section for more detailed communication specifications.
  5. Measurement conditions: PVC pole (diameter 75 mm, length 1 m), normal temperature.
  6. Objects detected within the distance range (measured directly in front of the sensor): 61 cm (24.0 in) - 100 cm (39.4 in): ±15 cm (5.9 in); 31 cm (12.2 in) - 60 cm (23.6 in): ±10 cm (3.9 in); within 30 cm (11.8 in): ±10 cm (3.9 in).
Detection Zone / Horizontal Detection Zone / Vertical Detection Zone / Distance Measurement

Direct measurement

Both transmission and reception are performed by the sensor (RL, RCL, RCR, RR during operation of each sensor).

Indirect measurement

(RCL → RL, RCL → RCR, RCR → RCL, RCR → RR are performed in order.) With two or three sensors, one of them sends a transmission while the others receive a reply.

Direct and indirect measurement at the same time.

With two or three sensors, one sensor performs transmission and reception, and the others only perform reception.
PAS Alarm: When the RPAS sensor detects an object, the warning is activated with an audible warning device such as a buzzer. The PAS sensor sends data to the BCM via LIN communication, and the BCM outputs the warning sound for each PAS sensor by priority. The visible warning device, such as the instrument cluster, operates only when it sends the signal.
  • Display/buzzer information processing method of the BCM sensor: When information is received from the RL/RR sensors, the BCM directly processes each sensor's information related to the display function and buzzer output. For buzzer output from the CL/CR sensors, the BCM processes the central combination information, giving priority to both sensors. Otherwise, when information is received from faulty display units, the BCM sends each sensor's information to the instrument cluster.
Special system operation: When the system is turned on (after IGN ON and in R gear), the MICOM checks the channel of all sensors. If no errors are detected, the buzzer sounds for 300 ms, then 500 ms. However, if an error is detected, the corresponding faulty sensor is indicated instead of the initial start alarm. The function for accessing normal mode is shown below.
With the R gear engaged, the system operates as shown below.
When the R gear is disengaged, the system operates as shown below.
※ Permissible signal error range ±10%. Alarm output characteristics classified by distance between sensors. The status logic according to alarm level priority is as follows. (Identical sensor)
* Determination of β value
  1. Sensor with lower priority disabled: α = 0 ms
  2. Sensor with lower priority is the 1st level warning: α < 340 ms
  3. Sensor with lower priority is the 2nd level warning: α < 170 ms
  4. Sensor with lower priority is the 1st level warning: β = 1700 ms
  5. Sensor with lower priority is the 2nd level warning: β = 1700 ms
  6. Sensor with lower priority is the 3rd level warning: β = 700 ms
  7. First warning zone (61 cm to 100 cm)
  8. Second warning zone (31 cm to 60 cm)
  9. Third warning zone (less than 30 cm)
  10. Malfunction signal period
    1. With visible display
* Determination of β value. The obstacle detection distance alarm control is shown below. Visible alarm indicator setting: When the shift lever is moved to the R position, the indicator on the instrument cluster illuminates as shown in the illustration below. When the system detects an object, it immediately turns on the indicator. During object detection, if there is no object, the indicator, which is not in the alarm state, illuminates for two seconds and then turns off object detection. (However, when changing from the third-stage alarm state to the non-alarm state, it activates the third-stage alarm for two seconds and then turns off.)
  • It shows only the obstacle detection position.
  • At the third level alarm, the indicator flashes at one-second intervals.
  • During normal alarm level display, the RCR/RCL indicator illuminates. Combined by priority.
Malfunction Handling

LIN BUS error case disabled

SECTION Error confirmation condition Error suppression condition
Initial routine LIN BUS OFF detected once Error is not suppressed in initial mode.
Normal routine LIN BUS OFF is detected a specified number of times in succession The malfunction is cleared when the BCM or LIN master detects that the LIN bus is on four times in succession in normal mode.

※ Note:
  1. When counting errors, the output message or signal must be transmitted as the last valid value.
  2. Error in initial mode: the malfunction buzzer (BCM) operates with the default display (instrument cluster).
  3. Error in normal mode: the malfunction is displayed only on the instrument cluster, without buzzer.

Sensor error (LIN message: 0x08)

SECTION Error confirmation condition Error suppression condition
Initial routine Single detection of sensor malfunction message Error is not suppressed in initial mode.
Normal routine Detection of sensor malfunction message four times in succession The malfunction is cleared when the BCM or LIN master detects that the LIN bus is on four times in succession in normal mode.

※ On the malfunction display, the RCR/RCL indicator is displayed separately. ※ Note:
  1. When counting errors, the output message or signal must be transmitted as the last valid value.
  2. Error in initial mode: the malfunction buzzer (BCM) operates with the default display (instrument cluster).
  3. Error in normal mode: the malfunction is displayed only on the instrument cluster, without buzzer.
  4. When an error appears in the transfer state, the sensors send the same error state for the indirect condition.
Standard communication: The PAS sends the object detection result and the sensor diagnosis result to the BCM in accordance with this document, and the BCM controls the alarm. The indicator shows the transmitted position and alarm data. When an alarm is active, it detects the nearest object and first notifies the nearest object-related sensor. (For example, if RL is a first-stage alarm and RR is a third-stage alarm, the RR alarm has priority.)

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