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

This skid control ECU inputs the stop light switch signal and detects the status of 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.
OK:
Stop light switch function is normal.
HINT: Check the stop light bulb as it may have burnt out.

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





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






Result:






C -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT)
B -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
A -- Continue to next step.
3. RECONFIRM DTC
(a) Clear the DTC .
(b) 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 -- END
A -- REPLACE BRAKE ACTUATOR ASSEMBLY
4. INSPECT STOP LIGHT SWITCH (POWER SOURCE TERMINAL VOLTAGE)





(a) Disconnect the stop light switch 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. INSPECT STOP LIGHT SWITCH





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






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





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





HINT:
- When troubleshooting in accordance with the DTC CHART, check DTCs before replacing the brake actuator assembly .
- When troubleshooting in accordance with the PROBLEM SYMPTOMS TABLE, be sure to follow the table before replacing the brake actuator assembly .

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