ABS (Antilock Brake System)

BRAKE CONTROL: ANTI-LOCK BRAKE SYSTEM: C1249/58: Stop Light Switch Circuit

DTC C1249/58 - Stop Light Switch Circuit

DESCRIPTION

This circuit recognizes brake operation by sending a stop light signal to the skid control ECU.
The skid control ECU has an open detection circuit, which outputs this DTC when detecting an open in the stop light signal input line (STP terminal) or the ground line of the stop light circuit with the stop light switch OFF (brake pedal not depressed).






WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK STOP LIGHT SWITCH OPERATION (STOP LIGHT SWITCH CIRCUIT)
(a) Check that the stop light comes on when the brake pedal is depressed and goes off when the brake pedal is released.
OK:






NG -- INSPECT STOP LIGHT SWITCH ASSEMBLY (POWER SOURCE TERMINAL VOLTAGE)
OK -- Continue to next step.
2. INSPECT SKID CONTROL ECU CONNECTOR (STP TERMINAL)





(a) Disconnect the skid control ECU connector.
(b) Measure the voltage according to the value(s) in the table below.
Voltage:






NG -- CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH TO SKID CONTROL ECU)
OK -- Continue to next step.
3. RECONFIRM DTC
(a) Clear the DTC.
(b) Start the engine.
(c) Depress the brake pedal several times to test the stop light circuit.
(d) Check that the same DTC is recorded.
HINT: Reinstall the sensors, connectors, etc. and restore the vehicle to its prior condition before rechecking for DTCs.

Result:






B -- REPLACE BRAKE ACTUATOR ASSEMBLY
A -- END
4. INSPECT STOP LIGHT SWITCH ASSEMBLY (POWER SOURCE TERMINAL VOLTAGE)





(a) Disconnect the stop light switch connector.
(b) Measure the voltage according to the value(s) in the table below.
Voltage:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)
OK -- Continue to next step.
5. INSPECT STOP LIGHT SWITCH ASSEMBLY





(a) Disconnect the stop light switch assembly connector.
(b) Measure the resistance according to the value(s) in the table below.
Resistance:






NG -- REPLACE STOP LIGHT SWITCH ASSEMBLY
OK -- Continue to next step.
6. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH TO SKID CONTROL ECU)





(a) Disconnect the stop light switch connector and skid control ECU connector.
(b) Measure the resistance according to the value(s) in the table below.
Resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH TO SKID CONTROL ECU)
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT CIRCUIT)