ABS (Antilock Brake System)

BRAKE CONTROL: ANTI-LOCK BRAKE SYSTEM: C1249/49: Open in Stop Light Switch Circuit

DTC C1249/49 - Open in Stop Light Switch Circuit

DESCRIPTION

The skid control ECU inputs the stop light switch signal and detects the status of the brake operation.
The skid control ECU has an open detection circuit. If an open in the stop light switch input line or GND side stop light circuit is detected when the stop light switch is off, this DTC is output.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

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

HINT: Check the stop light bulb because it may be burnt out.

OK:
Stop light switch function is normal.
NG -- INSPECT STOP LIGHT SWITCH
OK -- Continue to next step.
2. INSPECT SKID CONTROL ECU (STP TERMINAL)





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





NG -- CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH - SKID CONTROL ECU)
OK -- REPLACE BRAKE ACTUATOR ASSEMBLY
3. INSPECT STOP LIGHT SWITCH





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





NG -- REPLACE STOP LIGHT SWITCH
OK -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH - 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.
Standard resistance:





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





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE BRAKE ACTUATOR ASSEMBLY