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Brake Warning Light Remains On






BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: Brake Warning Light Remains ON; 2013 MY FR-S [03/2012 -]
- Brake Warning Light Remains ON

DESCRIPTION

The skid control ECU (brake actuator assembly) is connected to the combination meter assembly via CAN communication.

If any of the following is detected, the brake warning light remains on:

* The skid control ECU (brake actuator assembly) connector is disconnected from the skid control ECU (brake actuator assembly).

* The brake fluid level is insufficient.

* The parking brake is applied.

* EBD operation is not possible.

WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
* When replacing the skid control ECU (brake actuator assembly), perform VSC sensor neutral memorization Programming and Relearning.
* Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1. CHECK CAN COMMUNICATION SYSTEM

(a) Check if a CAN communication system DTC is output Diagnosis System.

Result:





B -- INSPECT CAN COMMUNICATION SYSTEM How to Proceed With Troubleshooting
A -- Continue to next step.

2. CHECK IF BRAKE ACTUATOR ASSEMBLY CONNECTOR IS SECURELY CONNECTED

(a) Check if the skid control ECU (brake actuator assembly) connector is securely connected.

OK:

The connector is securely connected.

NG -- CONNECT CONNECTOR TO ECU CORRECTLY
OK -- Continue to next step.

3. CHECK BATTERY

(a) Check the battery voltage.

Standard Voltage:

11 to 14 V

NG -- CHECK OR REPLACE CHARGING SYSTEM COMPONENT OR BATTERY Component Tests and General Diagnostics
OK -- Continue to next step.

4. CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)

(a) Disconnect the skid control ECU (brake actuator assembly) connector.









(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)
OK -- Continue to next step.

5. CHECK HARNESS AND CONNECTOR (GND1 TERMINAL)

(a) Turn the ignition switch off.









(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (GND1 CIRCUIT)
OK -- Continue to next step.

6. READ VALUE USING TECHSTREAM (PARKING BRAKE SWITCH)

(a) Reconnect the skid control ECU (brake actuator assembly) connector.

(b) Connect the Techstream to the DLC3.

(c) Turn the ignition switch to ON.

(d) Select the Data List using the Techstream Data List / Active Test.

ABS/VSC/TRAC





(e) Using the Techstream, check the switch operation signal received when the parking brake is operated.

OK:

When the parking brake is operated, the display changes as shown above.

NG -- INSPECT PARKING BRAKE SWITCH ASSEMBLY
OK -- Continue to next step.

7. INSPECT BRAKE FLUID LEVEL WARNING SWITCH

(a) Turn the ignition switch off.









(b) Remove the reservoir filler cap and the strainer.

(c) Disconnect the brake fluid level warning switch connector.

(d) Measure the resistance according to the value(s) in the table below.

HINT
A float is located inside the reservoir. Its position changes according to the brake fluid level.

Standard Resistance:





HINT
If there is no problem after finishing the above check, adjust the brake fluid level to the MAX level.

NG -- REPLACE BRAKE MASTER CYLINDER SUB-ASSEMBLY Removal
OK -- Continue to next step.

8. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - BRAKE FLUID LEVEL WARNING SWITCH)

(a) Disconnect the combination meter assembly connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

9. INSPECT COMBINATION METER ASSEMBLY

(a) Reconnect the combination meter assembly connector and the brake fluid level warning switch connector.

(b) Perform an Active Test of the combination meter assembly (meter CPU) using the Techstream Meter / Gauge System.

(c) Check the combination meter assembly.

OK:

The brake warning light turns on or off in accordance with the Active Test operation.

HINT
If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing parts Problem Symptoms Table.

NG -- REPLACE COMBINATION METER ASSEMBLY Removal

OK -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal

10. INSPECT PARKING BRAKE SWITCH ASSEMBLY

(a) Turn the ignition switch off.









(b) Disconnect the parking brake switch assembly connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- REPLACE PARKING BRAKE SWITCH ASSEMBLY Removal
OK -- Continue to next step.

11. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - PARKING BRAKE SWITCH ASSEMBLY)

(a) Disconnect the instrument panel junction block assembly connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

12. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

(a) Remove the instrument panel junction block assembly Removal.

(b) Remove the main body ECU (network gateway ECU) from the instrument panel junction block assembly Removal.

(c) Measure the resistance according to the value(s) in the table below.









Standard Resistance:





HINT
If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing parts Problem Symptoms Table.

NG -- REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Removal

OK -- REPLACE MAIN BODY ECU (NETWORK GATEWAY ECU) Removal
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