COMPONENT LOCATION |
GENERAL DESCRIPTION |
This switch is mounted on the pedal assembly and is used to indicate brake pedal status to the HECU.
The switch is turned on when brake is pressed.
The brake light switch is a normally-open contact which runs to battery voltage when active (brake pressed).
When passive (brake released), the cable is grounded via the brake light bulbs.
DTC DESCRIPTION |
The brake light signal is a reference to judge driver’s intention for braking.
The HECU checks open or short circuit of brake light switch for normal ESP control.
If an error is present, the warning lamp will illuminate.
DTC DETECTING CONDITION |
Item | Detecting Condition | Possible cause | ||||||||
DTC Strategy |
|
| ||||||||
Enable Conditions |
| |||||||||
Fail Safe |
|
SPECIFICATION |
Brake Light Switch | Voltage Range of “High” | Voltage Range of “Low” |
7.0V ~ 16.0V | 0V ~ 3.0V |
DIAGNOSTIC CIRCUIT DIAGRAM |
MONITOR SCANTOOL DATA |
1. | Connect scantool to Data Link Connector(DLC) |
2. | Ignition “ON” & Engine “OFF”. |
3. | Press the brake pedal. |
4. | Monitor the “BRAKE SWITCH” parameter on the scantool.
Fig 1) Service data at not pressing the break pedal Fig 2) Service data at pressing the break pedal |
5. | Whenever brake pedal is pushed down, is the brake switch’s scantool data changed ON/OFF?
|
TERMINAL AND CONNECTOR INSPECTION |
1. | Many malfunctions in the electrical system are caused by poor harness(es) and terminal condition. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage. |
2. | Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. |
3. | Has a problem been found?
|
SIGNAL CIRCUIT INSPECTION |
Signal circuit inspection (brake pedal isn’t pressed)
■ Open or Short Check |
1. | Ignition “ON” & Engine “OFF”. |
2. | Measure voltage between stop lamp switch (brake switch) terminal of the HECU harness connector and hassis ground.
|
3. | Is the measured waveform within specifications?
|
Signal Circuit Inspection (brake pedal is pressed)
■ Open or Short Check |
1. | Ignition “ON” & Engine “OFF”. |
2. | Press the brake pedal. |
3. | Measure voltage between stop lamp switch (brake switch) terminal of the HECU harness connector and chassis ground.
|
4. | Is the measured waveform within specifications?
|
COMPONENT INSPECTION |
■ Brake light switch Check |
1. | Ignition “OFF” & Engine “OFF”. |
2. | Disconnect the stop lamp switch connector. |
3. | Measure resistance between power terminal and siganl terminal of the stop lamp switch connector.
|
4. | Is the measured value within specifications?
|