C1249

BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C1249/49: Open in Stop Light Switch Circuit
C1249/49 - Open in Stop Light Switch Circuit

DESCRIPTION

The skid control ECU receives the stop light switch assembly signal and detects the brake pedal operation status.

The skid control ECU has an open detection circuit, which stores this DTC if it detects an open in the stop light input line or ground line of the stop light circuit with the stop light switch assembly off (brake pedal not depressed).





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
When replacing the skid control ECU (brake booster with master cylinder assembly), perform initialization and calibration of the linear solenoid valve Initialization.

PROCEDURE

1. CHECK STOP LIGHT OPERATION

(a) Check that the stop lights come on when the brake pedal is depressed, and go off when the brake pedal is released.

OK:





NG -- CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)
OK -- Continue to next step.

2. READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH ASSEMBLY)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Select the Data List on the Techstream Data List / Active Test.

ABS/VSC/TRAC





(d) Check that the stop light switch assembly display observed on the Techstream changes according to brake pedal operation.

OK:

The Techstream displays ON or OFF according to brake pedal operation.

NG -- CHECK HARNESS AND CONNECTOR (STP TERMINAL)
OK -- Continue to next step.

3. RECONFIRM DTC

(a) Turn the power switch off.

(b) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(c) Turn the power switch on (READY).

(d) Depress the brake pedal several times to test the stop light circuit.

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

Result:





HINT
If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step Problem Symptoms Table.

B -- REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY Removal

A -- CHECK FOR INTERMITTENT PROBLEMS How To Proceed With Troubleshooting

4. CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)

(a) Check that the STOP (7.5 A) fuse is normal.





(b) Make sure that there is no looseness at the locking part and the connecting part of the connector.

(c) Disconnect the stop light switch assembly connector.

(d) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





Text in Illustration





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)
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:





Text in Illustration





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

6. CHECK HARNESS AND CONNECTOR (SWITCH INPUT)

(a) Reconnect the stop light switch assembly connector.





(b) Remove the stop light control relay (STOP relay).

(c) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





Text in Illustration





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

7. INSPECT STOP LIGHT CONTROL RELAY (STOP RELAY)

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





Standard Resistance:





Text in Illustration





NG -- REPLACE STOP LIGHT CONTROL RELAY (STOP RELAY)
OK -- Continue to next step.

8. CHECK HARNESS AND CONNECTOR (STP TERMINAL)

(a) Install the stop light control relay (STOP relay).





(b) Make sure that there is no looseness at the locking part and the connecting part of the connector.

(c) Disconnect the skid control ECU (brake booster with master cylinder assembly) connector.

(d) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





Text in Illustration





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT)
OK -- Continue to next step.

9. RECONFIRM DTC

(a) Reconnect the skid control ECU (brake booster with master cylinder assembly) connector.

(b) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(c) Turn the power switch on (READY).

(d) Depress the brake pedal several times to test the stop light circuit.

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

Result:





HINT
* If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step Problem Symptoms Table.
* If the lighting system is normal but the DTC is still output, replace the skid control ECU (brake booster with master cylinder assembly) Removal.

B -- INSPECT LIGHTING SYSTEM (STOP LIGHT CIRCUIT) How To Proceed With Troubleshooting

A -- CHECK FOR INTERMITTENT PROBLEMS How To Proceed With Troubleshooting

10. CHECK HARNESS AND CONNECTOR (STP TERMINAL)

(a) Turn the power switch off.





(b) Make sure that there is no looseness at the locking part and the connecting part of the connector.

(c) Disconnect the skid control ECU (brake booster with master cylinder assembly) connector.

(d) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





Text in Illustration





HINT
If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step Problem Symptoms Table.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT)

OK -- REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY Removal