Electronic Stability Control (ESC)

FAILURE DIAGNOSIS

GENERAL

1. In principle, ESC and TCS controls are prohibited in case of ABS failure.
2. When ESC or TCS fail, only the failed system control is prohibited.
3. However, when the solenoid valve relay should be turned off in case of ESC fail, refer to the ABS fail-safe.
4. Information on ABS fail-safe is identical with the fail-safe in which ESC is not installed.

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.
1) When the failure is not detected now
2) When ABS and ESC are not in control.
3) Initial checkup is not made after ECU power on.
4) If the vehicle speed is over 409 mph (8 km/h) when the brake lamp switch is off.
5) 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 fail in the following cases.
1) When the power is normal.
2) From the point in which the vehicle speed reaches 4.9 mph (8 km/h) after HECU power on.

COUNTER MEASURES 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. ABS warning lamp turns on when ABS is fail.
2. TCS warning lamp turns on when TCS is fail.
3. ESC operation lamp turns on and TCS OFF warning lamp blinks when ESC is fail.

When power voltage and valve relay voltage are abnormal, input/output related failure judgment is not made.

WARNING LAMP & FUNCTION LAMP:

1. EBD warning lamp control
The EBD warning lamp indicates the operating condition of the EBD function.
The EBD warning lamp is on
- During the initialization phase (3 seconds)
- In the event of inhibition of EBD functions.
- Depending on the warning lamp module, when the controller is switched off as long as voltage is applied at the ignition terminal (IG1).

2. ABS warning lamp control
The ABS warning lamp indicates the operating condition of the ABS function.
The ABS warning lamp is on
- During the initialization phase (3 seconds)
- In the event of inhibition of ABS functions
- Depending on the warning lamp module, when the controller is switched off as long as voltage is applied at the ignition terminal (IG1).
- During diagnostics.

3. TCS/ESC warning lamp control
The TCS/ESC warning lamp indicates the operating condition of the TCS/ESC function.
The TCS/ESC warning lamp is on:
- During the initialization phase (3 seconds)
- In the event of inhibition of TCS/ESC functions
- During diagnostics.

4. TCS/ESC function lamp control
The TCS/ESC function lamp indicates the operating condition of the TCS/ESC function.
The TCS/ESC function lamp is on:
- During the initialization phase (3 seconds)
The TCS/ESC function lamp is blinking:
- During TCS/ESC control
- At the ESC off mode depending on ESC off switch, ESC control is available and ESC function lamp is blinking only when brake is turned on by driver.

SAFETY CONCEPT (ESC)

When any failures are occurred in the ESC system, the ESC ECU turns on the warning lamps and inhibits the control corresponding that as follows.