C1249

BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: C1249/49: Open in Stop Light Switch Circuit


DESCRIPTION

The stop light switch signal is input to the skid control ECU and the skid control ECU 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 stored.





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
When replacing the master cylinder solenoid, perform zero point calibration Programming and Relearning.

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.

NG -- INSPECT STOP LIGHT SWITCH ASSEMBLY (POWER SOURCE TERMINAL)
OK -- Continue to next step.

2. INSPECT SKID CONTROL ECU (STP TERMINAL)

(a) Disconnect the A24 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

B -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE Problem Symptoms Table
A -- Continue to next step.

3. RECONFIRM DTC

(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(b) Check if the same DTC is output Reading and Clearing Diagnostic Trouble Codes.

HINT
Reinstall the sensors, connectors, etc. and restore the previous vehicle conditions before rechecking for DTCs.

Result





B -- USE SIMULATION METHOD TO CHECK How To Proceed With Troubleshooting

A -- REPLACE MASTER CYLINDER SOLENOID

4. INSPECT STOP LIGHT SWITCH ASSEMBLY (POWER SOURCE TERMINAL)

(a) Disconnect the A30 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
OK -- Continue to next step.

5. INSPECT STOP LIGHT SWITCH ASSEMBLY

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





Standard Resistance:





NG -- REPLACE STOP LIGHT SWITCH ASSEMBLY Removal
OK -- Continue to next step.

6. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - STOP LIGHT SWITCH)

(a) Disconnect the A24 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 Diagnostic Trouble Code Chart, check DTCs before replacing the master cylinder solenoid Reading and Clearing Diagnostic Trouble Codes.
- When troubleshooting in accordance with the Problem Symptoms Table, be sure to follow the table before replacing the master cylinder solenoid Problem Symptoms Table.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE MASTER CYLINDER SOLENOID