ASCD Brake Switch

ASCD BRAKE SWITCH

Description

When the brake pedal is depressed, ASCD brake switch is turned OFF and stop lamp switch is turned ON.
ECM detects the state of the brake pedal by this input of two kinds (ON/OFF signal).
System Description for the ASCD function.


Component Function Check


1. CHECK ASCD BRAKE SWITCH FUNCTION

With CONSULT
1.Turn ignition switch ON.
2.Select "BRAKE SW-1" in "DATA MONITOR" mode with CONSULT.
3.Check "BRAKE SW-1" indication under the following conditions.





Without CONSULT
1.Turn ignition switch ON.
2.Check the voltage between ECM harness connector terminals as follows.





Is the inspection result normal?
YES- INSPECTION END
NO- Go to .


Diagnosis Procedure


1. CHECK ASCD BRAKE SWITCH POWER SUPPLY CIRCUIT

1.Turn ignition switch OFF.
2.Disconnect ASCD brake switch harness connector.
3.Turn ignition switch ON.
4.Check the voltage between ASCD brake switch harness connector and ground.





Is the inspection result normal?
YES- GO TO 3.
NO- GO TO 2.

2. DETECT MALFUNCTIONING PART

Check the following.
- Fuse block (J/B) connector E103
- 10 A fuse (No. 3)
- Harness for open or short between ASCD brake switch and fuse
- Repair open circuit or short to ground in harness or connectors.

3. CHECK ASCD BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.Turn ignition switch OFF.
2.Disconnect ECM harness connector.
3.Check the continuity between ASCD brake switch harness connector and ECM harness connector.





4.Also check harness for short to ground and short to power.
Is the inspection result normal?
YES- GO TO 5.
NO- GO TO 4.

4. DETECT MALFUNCTIONING PART

Check the following.
- Harness connectors E106, M6
- Harness for open or short between ECM and ASCD brake switch
- Repair open circuit or short to ground or short to power in harness or connectors.

5. CHECK ASCD BRAKE SWITCH


Is the inspection result normal?
YES- GO TO 6.
NO- Replace ASCD brake switch.

6. CHECK INTERMITTENT INCIDENT

Intermittent Incident.
- INSPECTION END


Component Inspection (ASCD Brake Switch)


1. CHECK ASCD BRAKE SWITCH-I

1.Turn ignition switch OFF.
2.Disconnect ASCD brake switch harness connector.
3.Check the continuity between ASCD brake switch terminals under the following conditions.





Is the inspection result normal?
YES- INSPECTION END
NO- GO TO 2.

2. CHECK ASCD BRAKE SWITCH-II

1.Adjust ASCD brake switch installation. Adjustments.
2.Check the continuity between ASCD brake switch terminals under the following conditions.





Is the inspection result normal?
YES- INSPECTION END
NO- Replace ASCD brake switch.