Vehicle Stability Control System
BRAKE CONTROL: VEHICLE STABILITY CONTROL SYSTEM: C1249/49: Open in Stop Light Switch Circuit
DESCRIPTION
The skid control ECU inputs the stop light switch signal and the condition of brake operation.
The skid control ECU has an open detection circuit, which outputs this DTC when an open circuit is detected in the stop light switch input circuit while the stop light switch is OFF.
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE:
When replacing the skid control ECU, perform zero point calibration and store system information Vehicle Stability Control System.
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 -- INSPECT STOP SW FUSE
OK -- Continue to next step.
2. READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH AND BRAKE PEDAL LOAD SENSING SWITCH)
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Select the Data List mode on the Techstream Data List / Active Test.
ABS / VSC / TRAC
(d) Check that the stop light display observed on the Techstream changes when the brake pedal is depressed.
OK:
When the brake pedal is depressed, the Techstream displays "ON".
(e) Depress the brake pedal slowly, and check when the stop light switch and brake pedal load sensing switch turn ON.
OK:
First the stop light switch should turn ON, and then the brake pedal load sensing switch should turn ON.
Result:
C -- CHECK BRAKE PEDAL AND STOP LIGHT SWITCH INSTALLATION
B -- CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - STOP LIGHT SWITCH)
A -- Continue to next step.
3. INSPECT SKID CONTROL ECU (IG1 TERMINAL)
(a) Turn the engine 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 connector.
(d) Turn the engine switch on (IG).
(e) Measure the voltage according to the value(s) in the table below.
Standard voltage:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1 CIRCUIT)
OK -- Continue to next step.
4. INSPECT SKID CONTROL ECU (GND TERMINAL)
(a) Turn the engine switch off.
(b) Make sure that there is no looseness at the locking part and the connecting part of the connectors.
(c) Disconnect the skid control ECU connectors.
(d) Measure the resistance according to the value(s) in the table below.
Standard resistance:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)
OK -- Continue to next step.
5. RECONFIRM DTC
(a) Reconnect the skid control ECU connectors.
(b) Clear the DTCs Vehicle Stability Control System.
(c) Start the engine.
(d) Depress the brake pedal several times to test the stop light circuit.
(e) Check if the same DTC is recorded Vehicle Stability Control System.
Result:
HINT
If troubleshooting has been carried out according to the Problem Symptoms Table, refer back to the table and proceed to the next step Problem Symptoms Table.
B -- REPLACE SKID CONTROL ECU Removal
A -- CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) Diagnosis System
6. INSPECT STOP SW FUSE
(a) Remove the STOP SW fuse from the main body ECU RH (cowl side junction block RH).
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:
NG -- REPLACE STOP SW FUSE
OK -- Continue to next step.
7. INSPECT STOP LIGHT SWITCH (POWER SOURCE TERMINAL)
(a) Install the STOP SW fuse.
(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 connector.
(d) 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.
8. 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.
9. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - STOP LIGHT SWITCH)
(a) Make sure that there is no looseness at the locking part and the connecting part of the connector.
(b) Disconnect the skid control ECU connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
10. RECONFIRM DTC
(a) Reconnect the skid control ECU connector and the stop light switch connector.
(b) Clear the DTCs Vehicle Stability Control System.
(c) Start the engine.
(d) Depress the brake pedal several times to test the stop light circuit.
(e) Check if the same DTC is recorded Vehicle Stability Control System.
Result:
HINT
If troubleshooting has been carried out according to the Problem Symptoms Table, refer back to the table and proceed to the next step Problem Symptoms Table.
B -- REPLACE SKID CONTROL ECU Removal
A -- INSPECT LIGHTING SYSTEM (STOP LIGHT CIRCUIT) Symptom Related Diagnostic Procedures
11. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - STOP LIGHT SWITCH)
(a) Turn the engine switch off.
(b) Make sure that there is no looseness at the locking part and the connecting part of the connectors.
(c) Disconnect the skid control ECU connector and the stop light switch connector.
(d) Measure the resistance according to the value(s) in the table below.
Standard resistance:
HINT
If troubleshooting has been carried out according to the Problem Symptoms Table, refer back to the table and proceed to the next step Problem Symptoms Table.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE SKID CONTROL ECU Removal
12. CHECK BRAKE PEDAL AND STOP LIGHT SWITCH INSTALLATION
(a) Turn the engine switch off.
(b) Check the brake pedal height and stop light switch installation Adjustments.
OK:
The brake pedal height and stop light switch installation are normal.
HINT
If troubleshooting has been carried out according to the Problem Symptoms Table, refer back to the table and proceed to the next step Problem Symptoms Table.
NG -- ADJUST BRAKE PEDAL OR STOP LIGHT SWITCH Adjustments
OK -- REPLACE BRAKE PEDAL SUPPORT ASSEMBLY (BRAKE PEDAL LOAD SENSING SWITCH) Removal