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Electronic Stability Control (Esc) System - Except Hev: Other Kia Optima III

Anti-Lock/traction Control 26 illustrations ~1792 words

ABS Warning Lamp Module

The active ABS warning lamp module indicates the self-test and failure status of the ABS. The ABS warning lamp shall be on

  1. During the initialization phase after IGN ON. (continuously 3 seconds).
  2. In the event of inhibition of ABS functions by failure.
  3. During diagnostic mode.
  4. When the ECU Connector is separated from ECU.
  5. Cluster lamp is ON when communication is impossible with CAN module.

EBD/Parking Brake Warning Lamp Module

The active EBD warning lamp module indicates the self-test and failure status of the EBD. However, in case the Parking Brake Switch is turned on, the EBD warning lamp is always turned on regardless of EBD functions. The EBD warning lamp shall be on

  1. During the initialization phase after IGN ON. (continuously 3 seconds).
  2. When the Parking Brake Switch is ON or brake fluid level is low.
  3. When the EBD function is out of order.
  4. During diagnostic mode.
  5. When the ECU Connector is separated from ECU.
  6. Cluster lamp is ON when communication is impossible with CAN module.

ESC Function/Warning Lamp (ESC System)

The ESC function/warning lamp indicates the self-test and failure status of the ESC.

The ESC function/warning lamp is turned on under the following conditions

  1. During the initialization phase after IGN ON. (continuously 3 seconds).
  2. When the ESC function is inhibited by system failure.
  3. When the ESC control is operating. (Blinking - 2Hz)
  4. During diagnostic mode. (Except standard mode)
  5. Cluster lamp is ON when communication is impossible with CAN module.

ESC Off Lamp (ESC System)

The ESC Off lamp indicates the self-test and operating status of the ESC.

The ESC Off lamp operates under the following conditions

  1. During the initialization mode after IGN ON. (continuously 3 seconds).
  2. ESC Off lamp is On when driver input the ESC Off switch.

ESC On/Off Switch (ESC System)

The ESC On/Off Switch shall be used to toggle the ESC function between On/Off states based upon driver input. The On/Off switch shall be a normally open, momentary contact switch. Closed contacts switch the circuit to ignition. Initial status of the ESC function is on and switch toggle the state.

Scheme 24

Scheme 24: Circuit Diagram - ESC (1)
Scheme 24: Circuit Diagram - ESC (1)

Scheme 25

Scheme 25: Circuit Diagram - ESC (2)
Scheme 25: Circuit Diagram - ESC (2)

Scheme 26

Scheme 26: Circuit Diagram - ESC (3)
Scheme 26: Circuit Diagram - ESC (3)

Scheme 27

Scheme 27: ESC Connector Input/Output
Scheme 27: ESC Connector Input/Output
Connector TerminalSpecificationRemark
NoDescription
29IGNITION1 (+)High level of wake up voltage : 4.5V < V < 16.0V Low level of wake up voltage : V < 2.4V Max. current : I < 50mA
25POS. BATTERY 1. (SOLENOID)Over voltage range : 17.0 ± 0.5V Operating voltage range : 10.0 ± 0.5V < V < 16.0 ± 0.5V Low voltage range : 7.0 ± 0.5V < V < 9.5 ± 0.5V Max. current : I < 40A Max. leakage current : I < 0.25mA
1POS. BATTERY 2. (MOTOR)Operating voltage range: 10.0 ± 0.5V < V < 16.0 ± 0.5V Rush current : I < 110A Max current : I < 40A Max leakage current : I < 0.25mA
38GROUNDRated current : I <550mA Max. current: I < 40A
13PUMP MOTOR GROUNDRush current : I < 110A Max current : I < 40A
11SENSOR GROUNDRated current : I <250mA
4SENSOR POWERMax current Capability : I < 250mA Max voltage : V_BAT1 -0.8V
23BRAKE LIGHT SWITCHInput voltage (Low) : V < 2.0V Input voltage (High) : V > 6.0V Max. Input current : I < 3mA (@12.8V)
10ESC ON/OFF SWITCH
9BRAKE SWITCH
35CLUTCH SWITCH (M/T Only)Input voltage (Low) : V < 2.0V Input voltage (High) : V > 6.0V Max input current : I < 5mA (@12.8V)
28SENSOR FRONT RIGHT OUTPUTExternal pull up resistance :1 Kohms < R Output duty : 50 ± 20%
14CAN BUS LINE (LOW)Max. Input current : I < 10mA
26CAN BUS LINE (HIGH)
18SENSOR FRONT LEFT POWEROutput voltage : V_BAT1 -0.6V ~ V_BAT1 -1.1V Output current : Max 30mA
34SENSOR FRONT RIGHT POWER
19SENSOR REAR LEFT POWER
33SENSOR REAR RIGHT POWER
31SENSOR FRONT LEFT SIGNALInput current LOW : 5.9 ~ 8.4mA Input current HIGH : 11.8 ~ 16.8mA Frequency range : 1 ~ 2, 500Hz Input duty : 50 ± 10%
21SENSOR FRONT RIGHT SIGNAL
32SENSOR REAR LEFT SIGNAL
20SENSOR REAR RIGHT SIGNAL
12CAN SENSOR LINE (HIGH)Max. input current : I < 10mA
24CAN SENSOR LINE (LOW)
8BRAKE RELAYMax. current : I < 180mA Max. Output low voltage : V <1.2V
36RELAY STATE MONITORINGInput voltage (Low) : V < 2V Input voltage (High) : V > 6V Max. Input current : I < 10mA

TERMINALS REFERENCE CHART

Memory Of Fail Code

  1. It keeps the code as far as the backup lamp power is connected. (O)
  2. It keeps the code as far as the HCU power is on. (X)

Failure Checkup

  1. Initial checkup is performed immediately after the HECU power on.
  2. Valve relay checkup is performed immediately after the IG2 ON.
  3. It executes the checkup all the time while the IG2 power is on.
  4. Initial checkup is made in the following cases. When the failure is not detected now. When ABS and ESC are not in control. Initial checkup is not made after ECU power on. If the vehicle speed is over 5 mph (8 km/h) when the brake lamp switch is off. When the vehicle speed is over 24.8 mph (40 km/h).
  5. Though, it keeps on checkup even if the brake lamp switch is on.
  6. When performing ABS or ESC control before the initial checkup, stop the initial checkup and wait for the HECU power input again.
  7. Judge failure in the following cases. When the power is normal. From the point in which the vehicle speed reaches 4.9 mph (8 km/h) after HECU power on.

Countermeasures In Fail

  1. Turn the system down and perform the following actions and wait for HECU power OFF.
  2. Turn the valve relay off.
  3. Stop the control during the operation and do not execute any until the normal condition recovers.

Warning Lamp ON

  1. ESC warning lamp turn on for 3 sec after IGN ON.
  2. ESC function lamp blinks when ESC Act.
  3. If ESC fail occurred, ESC warning lamp turns ON.
  4. ESC OFF lamp turn on in case of ESC Switch OFF 3 sec after IGN ON

Scheme 28

Scheme 28: Standard Flow Of Diagnostic Troubleshooting
Scheme 28: Standard Flow Of Diagnostic Troubleshooting

Detecting Condition

Trouble SymptomsPossible Cause
Brake operation varies depending on driving conditions and road surface conditions, so diagnosis can be difficult. However if a normal DTC is displayed, check the following probable cause. When the problem is still occurring, inspect the ABS control module.Faulty power source circuit Faulty wheel speed sensor circuit Faulty hydraulic circuit for leakage Faulty HECU

TROUBLE SYMPTOM CHART

Check The Wheel Speed Sensor Circuit

  1. Refer to «ELECTRONIC STABILITY CONTROL SYSTEM DIAGNOSIS»(ref-429651) . .
  2. Is it normal? YES Check the hydraulic circuit for leakage. NO Repair or replace the wheel speed sensor.

Check The Hydraulic Circuit For Leakage

  1. Refer to «BRAKE LINE»(ref-429579-S20329562052011101500000) .
  2. Inspect leakage of the hydraulic lines.
  3. Is it normal? YES The problem is still occurring, replace the ABS control module. NO Repair the hydraulic lines for leakage.
Trouble SymptomsPossible Cause
Brake operation varies depending on driving conditions and road surface conditions, so diagnosis can be difficult. However if a normal DTC is displayed, check the following probable cause. When the problem is still occurring, inspect the ABS control module.Faulty power source circuit Faulty wheel speed sensor circuit Faulty hydraulic circuit for leakage Faulty HECU

TROUBLE SYMPTOM CHART

  1. Refer to «ELECTRONIC STABILITY CONTROL SYSTEM DIAGNOSIS»(ref-429651) . .
  2. Is it normal? YES Check the stop lamp switch circuit. NO Repair or replace the wheel speed sensor.

Scheme 29

Scheme 29: Check The Stop Lamp Switch Circuit
Scheme 29: Check The Stop Lamp Switch Circuit
  1. Check that stop lamp lights up when brake pedal is depressed and turns off when brake pedal is released.
  2. Measure the voltage between terminal 23 of the ABS control module harness side connector and body ground when brake pedal is depressed. Specification : approximately B+
  3. Is the voltage within specification? YES Check the hydraulic circuit for leakage. NO Repair the stop lamp switch. Repair an open in the wire between the ABS control module and the stop lamp switch.
  1. Refer to «BRAKE LINE»(ref-429579-S20329562052011101500000) .
  2. Inspection leakage of the hydraulic lines.
  3. Is it normal? YES The problem is still occurring, replace the ABS control module. NO Repair the hydraulic lines for leakage.
Trouble SymptomsPossible Cause
Possible defect in the power supply system (including ground) for the diagnosis line.An open in the wire Poor ground Faulty power source circuit

TROUBLE SYMPTOM CHART

Scheme 30

Scheme 30: Check The Power Supply Circuit For The Diagnosis
Scheme 30: Check The Power Supply Circuit For The Diagnosis
  1. Measure the voltage between terminal 16 of the data link connector and body ground. Specification : approximately B+
  2. Is voltage within specification? YES Check the ground circuit for the diagnosis. NO Repair an open in the wire. Check and replace fuse from the engine compartment junction block.

Scheme 31

Scheme 31: Check The Ground Circuit For The Diagnosis
Scheme 31: Check The Ground Circuit For The Diagnosis
  1. Check for continuity between terminal 4 of the data link connector and body ground.
  2. Is there continuity? NO Repair an open in the wire between terminal 4 of the data link connector and ground point.
Trouble SymptomsPossible Cause
When communication with GDS is not possible, the cause may be probably an open in the HECU power circuit or an open in the diagnosis output circuit.An open in the wire Faulty HECU Faulty power source circuit

TROUBLE SYMPTOM CHART

Check For Continuity In The CAN Line

  1. Disconnect the connector from the ABS control module.
  2. Check for continuity between terminals 26, 14 of the ABS control module connector and 3, 11 of the data link connector.
  3. Is there continuity? YES Check the power source of ABS control module. NO Repair an open in the wire.

Scheme 32

Scheme 32: Check The Power Source Of ABS Control Module
Scheme 32: Check The Power Source Of ABS Control Module
  1. Disconnect the connector from the ABS control module.
  2. Turn the ignition switch ON, measure the voltage between terminal 29 of the ABS control module harness side connector and body ground. Specification : approximately B+
  3. Is voltage within specification? YES Check for poor ground. NO Check the harness or connector between the fuse (10A) in the engine compartment junction block and the ABS control module. Repair if necessary.

Scheme 33

Scheme 33: Check For Poor Ground
Scheme 33: Check For Poor Ground
  1. Check for continuity between terminal 4 of the data link connector and ground point. YES Replace the ABS control module and recheck. NO Repair an open in the wire or poor ground
Trouble SymptomsPossible Cause
When current flows in the HECU the ABS warning lamp turns from ON to OFF as the initial check. Therefore if the lamp does not light up, the cause may be an open in the lamp power supply circuit, a blown bulb, an open in the both circuits between the ABS warning lamp and the HECU, and the faulty HECU.Faulty ABS warning lamp bulb Blown fuse is related to ABS in the engine compartment junction block Faulty ABS warning lamp module Faulty HECU

TROUBLE SYMPTOM CHART

Problem Verification

  1. Disconnect the connector from the ABS control module and turn the ignition switch ON.
  2. Does the ABS warning lamp light up? YES Inspect again after replacing the ABS HECU. NO Check the power source for the ABS warning lamp.

Scheme 34

Scheme 34: Check The Power Source For The ABS Warning Lamp
Scheme 34: Check The Power Source For The ABS Warning Lamp
  1. Disconnect the instrument cluster connector (M08) and turn the ignition switch ON.
  2. Measure the voltage between terminal (M08) 18 of the cluster harness side connector and body ground. Specification : approximately B+
  3. Is voltage within specification? YES Check the CAN circuit resistance for ABS warning lamp. NO Check for blown fuse.

Scheme 35

Scheme 35: Check The CAN Circuit Resistance For ABS Warning Lamp
Scheme 35: Check The CAN Circuit Resistance For ABS Warning Lamp
  1. Disconnect the instrument cluster connector (M08) and turn the ignition switch OFF.
  2. Measure the resistance between terminal (M08) 29 and 30 of the cluster harness side connector. Specification : 60ohms
  3. Is resistance within specification? YES Repair ABS warning lamp bulb or instrument cluster assembly. NO Check the CAN circuit wiring for ABS warning lamp.
Trouble SymptomsPossible Cause
If the HECU detects trouble, it lights the ABS warning lamp and at the same time prohibits ABS control. The HECU then records a DTC in memory. If the ABS warning lamp remains ON, even after the problem with the DTC is repaired and cleared, then the cause may be an open or short in the ABS warning lamp circuit.An open in the wire Faulty instrument cluster assembly Faulty ABS warning lamp module Faulty HECU

TROUBLE SYMPTOM CHART

Bleeding Of Brake System

This procedure should be followed to ensure adequate bleeding of air and filling of the ESC unit, brake lines and master cylinder with brake fluid.

Scheme 36

Scheme 36: Bleeding Of Brake System
Scheme 36: Bleeding Of Brake System

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Scheme 42
  1. Remove the reservoir cap and fill the brake reservoir with brake fluid. CAUTION: If there is any brake fluid on any painted surface, wash it off immediately. NOTE: When pressure bleeding, do not depress the brake pedal. Recommended fluid........ DOT3 or DOT4
  2. Connect a clear plastic tube to the wheel cylinder bleeder plug and insert the other end of the tube into a half filled clear plastic bottle.
  3. Connect the GDS to the data link connector located underneath the dash panel.
  4. Select and operate according to the instructions on the GDS screen. CAUTION: You must obey the maximum operating time of the ABS motor with the GDS to prevent the motor pump from burning. Select vehicle name. Select Anti-Lock Brake system. Select HCU air bleeding mode. Press "OK" to operate motor pump and solenoid valve. Wait 60 sec. before operating the air bleeding. (If not, you may damage the motor.) Perform the air bleeding.
  5. Pump the brake pedal several times, and then loosen the bleeder screw until fluid starts to run out without bubbles. Then close the bleeder screw (A). Front Rear
  6. Repeat step 5 until there are no more bubbles in the fluid for each wheel using the chart below for the order of bleeding process.
  7. Tighten the bleeder screw. Bleed screw tightening torque: 6.9 ~ 12.7 N.m (0.7 ~ 1.3 kgf.m, 5.1 ~ 9.4 lb-ft)

Advantages

  1. Function improvement of the base-brake system.
  2. Compensation for the different friction coefficients.
  3. Elimination of the proportioning valve.
  4. Failure recognition by the warning lamp.

Scheme 43

Scheme 43: Comparison Between Proportioning Valve And EBD
Scheme 43: Comparison Between Proportioning Valve And EBD

Scheme 44

Scheme 44: Components
Scheme 44: Components

Scheme 45

Scheme 45: Removal
Scheme 45: Removal

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Scheme 49
  1. Turn the ignition switch OFF.
  2. Remove the air duct (B) and air cleaner assembly (A).
  3. Remove the ECM connector (B) and the arrange the wiring harness (A).
  4. Pull up the lock of the HECU connector (A), then disconnect the connector.
  5. Remove the brake fluid from the master cylinder reservoir with a syringe. CAUTION: Be sure to completely remove foreign substances from around brake fluid reservoir and cap before opening the reservoir cap. If not, it may cause contamination of brake fluid and deterioration in braking performance. Do not spill brake fluid on the vehicle, it may damage the paint; if brake fluid does contact the paint, wash it off immediately with water.
  6. Disconnect the brake tubes from the HECU by unlocking the nuts counterclockwise with a spanner. Tightening torque: M10: 11.7 ~ 15.7 N.m (1.2 ~ 1.6 kgf.m, 8.7 ~ 11.6 lb-ft) M12: 18.6 ~ 22.6 N.m (1.9 ~ 2.3 kgf.m, 13.7 ~ 16.6 lb-ft)
  7. Loosen the HECU bracket bolts (A), then remove HECU and bracket. Tightening torque: 19.6 ~ 29.4 N.m (2.0 ~ 3.0 kgf.m, 14.5 ~ 21.7 lb-ft) CAUTION: Never attempt to disassemble the HECU. Never shock the HECU.
  8. Remove the 2 nuts (B), then remove the bracket from HECU. Tightening torque: 10.8 ~ 13.7 N.m (1.1 ~ 1.4 kgf.m, 8.0 ~ 10.1 lb-ft)

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