C1249

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

DTC C1249/49 - Open in Stop Light Switch Circuit

DESCRIPTION

The skid control ECU inputs the stop light switch signal and detects braking condition.
The skid control ECU has a circuit for open detection. The skid control ECU outputs the DTC if it detects an open in the stop light signal input line when the stop light switch is off or an open in the stop light circuit (skid control ECU side).






WIRING DIAGRAM





INSPECTION PROCEDURE
NOTICE:
When replacing the skid control ECU, perform initialization of linear solenoid valve and calibration Programming and Relearning.

PROCEDURE

1. INSPECT FUSE (STOP SW FUSE)
(a) Remove the STOP SW fuse from the main body ECU RH.
(b) Check the STOP SW fuse.
Standard resistance:
Below 1 Ohms
NG -- REPLACE FUSE (STOP SW FUSE)
OK -- Continue to next step.
2. READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH)
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch ON (IG).
(c) Select the Data List mode on the Techstream.

ABS / VSC / TRAC:





(d) Check that the stop light observed on the Techstream changes when the brake pedal is depressed.
OK:
When the brake pedal is depressed, the Techstream displays "ON".
OK -- CHECK WIRE HARNESS (SKID CONTROL ECU - LUGGAGE ROOM JUNCTION BLOCK ECU)
NG -- Continue to next step.
3. CHECK WIRE HARNESS (SKID CONTROL ECU - STOP LIGHT SWITCH)




(a) Disconnect the A13 ECU connector.
(b) Disconnect the A35 switch 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.
4. INSPECT STOP LIGHT SWITCH (POWER SOURCE TERMINAL)




(a) Disconnect the A35 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) Disconnect the stop light switch connector.
(b) 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 WIRE HARNESS (SKID CONTROL ECU - BODY GROUND)




(a) Disconnect the A13 and A15 ECU connectors.
(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.
7. RECONFIRM DTC
(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.
(b) Turn the power switch ON (READY).
(c) Depress the brake pedal several times to test the stop light circuit.
(d) Check if the same DTC is recorded Reading and Clearing Diagnostic Trouble Codes.
HINT: Reinstall the sensors, connectors, etc. and restore the vehicle to its prior condition before rechecking for DTCs.

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
A -- END
8. CHECK WIRE HARNESS (SKID CONTROL ECU - LUGGAGE ROOM JUNCTION BLOCK ECU)




(a) Disconnect the A13 ECU connector.
(b) Disconnect the LC 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 -- CHECK LIGHTING SYSTEM