TCS

C1513

Component Location:

General Description
The brake light switch indicates brake pedal status to the ABS control unit. The switch is turned on when brake is depressed. The brake light switch is a normally-open contact which runs to battery voltage when active (brake depressed).

DTC Description
The brake light signal is a reference to judge driver's intention for braking. ABS ECU monitor open circuit of brake light switch for normal ABS control.

DTC Detecting Condition:

Schematic 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 lamp switch" parameter on the scantool.






5. Whenever Brake pedal is pushed down, is the brake lamp switch's scantool data changed ON/OFF?

YES - Fault is intermittent caused by poor connection in brake light switch line and/or HECU's connector or was repaired and HECU memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.

NO - Go to "W/Harness Inspection" procedure.

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?

YES - Repair as necessary and then go to "Verification of Vehicle Repair" procedure.

NO - Go to "Signal circuit inspection" procedure.

Signal circuit inspection (brake pedal isn't depressed)
4. Ignition "ON" & Engine "OFF".
5. Don't press the brake pedal.
6. Measure voltage between the terminal "41" of the HECU harness connector and chassis ground.

Specification : Brake Light Switch - Approx. 0 V






7. Is the measured voltage within specifications?

YES - Go to "Signal Circuit Inspection (brake pedal is depressed)" procedure.

NO
- Check for open or blown 15 A fuse referring to "Circuit Diagram". Check for open or short to battery between the battery terminal (+) and the terminal "41" of the HECU harness connector. Repair as necessary and then go to "Verification of vehicle Repair" procedure.
- If OK, Go to "Component Inspection" Procedure.

Signal circuit inspection (brake pedal is depressed)
8. Ignition "ON" & Engine "OFF".
9. Press the brake pedal.
10. Measure voltage between the terminal "41" of the HECU harness connector and chassis ground.

Specification : Brake Light Switch - Approx. B+






11. Is the measured voltage within specifications?

YES - Fault is intermittent caused by open or short harness in brake light switch, faulty brake light switch or was repaired and HECU memory was not cleared. Go to "Verification of Vehicle Repair" procedure.

NO
- Check for open or short to ground between the battery terminal (+) and the terminal "30" of the HECU harness connector. Repair as necessary and then go to "Verification of vehicle Repair" procedure.
- If OK, Go to "Component Inspection" Procedure.

Component Inspection
1. Ignition "OFF".
2. Disconnect brake switch connector.
3. Measure resistance between the terminal "1,2", "3,4" of the brake switch.

Specification : Resistance between the terminal "1,2" of the brake switch - Infinite ohms (when the plunger is pushed down), 0 ohms (when the plunger isn't pushed down). Resistance between the terminal "3,4" of the brake switch - Infinite ohms (when the plunger is not pushed down), 0 ohms (when the plunger is pushed down).






4. Is the measured voltage within specifications?

YES - Fault is intermittent caused by open or short harness in brake light switch, faulty brake light switch or was repaired and HECU memory was not cleared. Go to "Verification of Vehicle Repair" procedure.

NO - Substitute with a known-good brake lamp switch and check for proper operation. If problem is corrected, replace brake light switch and then go to "Verification of Vehicle Repair" procedure.

Verification of Vehicle Repair
After a repair, it is essential to verify that the fault has been corrected.
1. Connect scan tool and select "Diagnostic Trouble Codes (DTCs)" mode
2. Using a Scantool, Clear DTC.
3. Operate the vehicle within DTC Detecting Condition in General Information.
4. Are any DTCs present?

YES - Go to the applicable troubleshooting procedure.

NO - System performing to specification at this time.