Open in Stop Light Switch Circuit - Electronically Controlled Brake System

BRAKE CONTROL: 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 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 Initialization.

PROCEDURE

1. INSPECT FUSE (STOP SW FUSE)

(a) Remove the STOP SW fuse from the cowl side J/B RH.

(b) Check the STOP SW fuse.

Resistance:

Below 1 Ohms (Continuity)

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) Start the engine.

(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".

NG -- CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU TO LUGGAGE ROOM J/B ECU)
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU TO STOP LIGHT SWITCH)

(a) Disconnect the skid control ECU connector and stop light switch connector.

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

Resistance:

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

4. 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.

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.

Resistance:

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

6. INSPECT SKID CONTROL ECU (GND TERMINAL)

(a) Disconnect the skid control ECU (A13, A15) connectors.

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

Resistance:

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

7. RECONFIRM DTC

(a) Clear the DTC Electronically Controlled Brake System.

(b) Start the engine.

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

(d) Check if the same DTC is recorded Electronically Controlled Brake System.

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 HARNESS AND CONNECTOR (SKID CONTROL ECU TO LUGGAGE ROOM J/B ECU)

(a) Disconnect the skid control ECU connector and luggage room J/B ECU connector.

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

Resistance:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- INSPECT LIGHTING SYSTEM