| Last Modified: 11-27-2007 | 1.6 J | |
| Service Category: Brake | Section: Brake Control/Dynamic Control System | |
| Model Year: 2008 | Model: LX570 | Doc ID: RM000001DXR00PX |
| Title: BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: DESCRIPTION (2008 LX570) | ||
|
Brake Warning Light Remains ON |
DESCRIPTION
The brake warning light comes on when brake fluid is insufficient, the parking brake is applied or the EBD is defective.
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE:
When replacing the master cylinder solenoid, perform zero point calibration
.
PROCEDURE
|
1. |
CHECK DTC |
(a) Check for DTCs
.
Result
|
Result |
Proceed to |
|---|---|
|
DTC is not output. |
A |
|
DTC is output. |
B |
|
|
2. |
INSPECT IF SKID CONTROL ECU CONNECTOR IS SECURELY CONNECTED |
(a) Check the skid control ECU connector connection.
OK:
The connector is securely connected.
|
|
3. |
INSPECT BATTERY |
(a) Check the battery voltage.
Standard Voltage:
11 to 14 V
|
|
4. |
CHECK CAN COMMUNICATION LINE |
(a) Turn the engine switch off.
(b) Connect the Techstream to the DLC3.
(c) Turn the engine switch on (IG) and the Techstream on.
(d) Select "CAN Bus Check" from the System Selection Menu screen, and follow the prompts on the screen to inspect the CAN Bus.
OK:
"CAN Bus Check" indicates no malfunctions in CAN communication.
|
|
5. |
CHECK DTC (for CAN Communication System) |
(a) Turn the engine switch off.
(b) Connect the Techstream to the DLC3.
(c) Turn the engine switch on (IG) and the Techstream on.
(d) Check for DTCs
.
Result
|
Result |
Proceed to |
|---|---|
|
CAN system DTC is not output. |
A |
|
CAN system DTC is output. |
B |
|
|
6. |
CHECK OPERATION OF BRAKE WARNING LIGHT (ACTIVE TEST) |
(a) Turn the engine switch off.
(b) Connect the Techstream to the DLC3.
(c) Turn the engine switch on (IG) and the Techstream on.
(d) Enter the following menus: Body Electrical / Combination Meter / Active Test.
(e) Check the condition of the brake warning light by operating the Techstream.
Combination Meter
|
Tester Display |
Test Part |
Control Range |
Diagnostic Note |
|---|---|---|---|
|
Indicat. Lamp Brake |
Brake Warning Light |
Warning light ON/OFF |
- |
OK:
The warning light turns on when operating the Techstream.
|
|
7. |
INSPECT SKID CONTROL ECU (IG1 TERMINAL) |
|
(a) Disconnect the A24 skid control ECU connector. |
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Switch Condition |
Specified Condition |
|---|---|---|
|
A24-46 (IG1) - Body ground |
Engine switch on (IG) |
11 to 14 V |
|
|
8. |
INSPECT SKID CONTROL ECU (GND TERMINAL) |
|
(a) Disconnect the A24 and A25 skid control ECU connectors. |
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A24-1 (GND1) - Body ground |
Always |
Below 1 Ω |
|
A24-32 (GND2) - Body ground |
Always |
Below 1 Ω |
|
A25-4 (GND3) - Body ground |
Always |
Below 1 Ω |
|
|
9. |
INSPECT PARKING BRAKE SWITCH |
|
(a) Disconnect the E53 parking brake switch connector. |
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Switch Condition |
Specified Condition |
|---|---|---|
|
1 - Body ground |
Parking brake switch on (Switch pin free) |
Below 1 Ω |
|
1 - Body ground |
Parking brake switch off (Switch pin pushed in) |
10 kΩ or higher |
|
|
10. |
CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - PARKING BRAKE SWITCH) |
|
(a) Measure the resistance according to the value(s) in the table below. Standard Resistance:
|
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