Open in Stop Light Switch Circuit - 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 (housed in the actuator assembly) 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 detecting an open in the stop light input line or the ground line of the stop light circuit with the stop light switch off (brake pedal not depressed).

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. INSPECT STOP FUSE

(a) Remove the STOP fuse from the main body ECU (instrument panel junction block).
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:

NG -- REPLACE STOP FUSE
OK -- Continue to next step.
2. CHECK STOP LIGHT OPERATION
(a) Install the STOP fuse.
(b) Check that the stop light comes on when the brake pedal is depressed, and goes off when the brake pedal is released.
OK:

NG -- INSPECT STOP LIGHT SWITCH (POWER SOURCE TERMINAL)
OK -- Continue to next step.
3. 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 -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT)
OK -- Continue to next step.
4. INSPECT SKID CONTROL ECU (IG1 TERMINAL)

(a) Turn the ignition switch to ON.
(b) 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.
5. INSPECT SKID CONTROL ECU (GND TERMINAL)

(a) Turn the ignition switch to OFF.
(b) 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.
6. RECONFIRM DTC
(a) Reconnect the skid control ECU connector.
(b) Clear the DTC ABS (Antilock Brake 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 ABS (Antilock Brake 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 BRAKE ACTUATOR ASSEMBLY
A -- CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION)
7. INSPECT STOP LIGHT SWITCH (POWER SOURCE TERMINAL)

(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.
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) Disconnect the skid control ECU connector.
(b) 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 DTC ABS (Antilock Brake 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 ABS (Antilock Brake System).
Result: