ASCD Brake Switch

ASCD BRAKE SWITCH

Component 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).
Refer to the ASCD function.


Diagnosis Procedure


1. CHECK OVERALL FUNCTION-I

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 voltage between ECM terminal 108 and ground under the following conditions.





OK or NG
OK- INSPECTION END
NG- GO TO 2.

2. 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 voltage between ASCD brake switch terminal 1 and ground with CONSULT or tester.
Voltage: Battery voltage
OK or NG
OK- GO TO 4.
NG- GO TO 3.

3. DETECT MALFUNCTIONING PART

Check the following.
- Harness connectors M31, E152
- Fuse block (J/B) connector M4
- 10 A fuse (No. 15)
- Harness for open or short between ASCD brake switch and fuse
- Repair open circuit or short to ground or short to power in harness or connectors.

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

1.Turn ignition switch OFF.
2.Disconnect ECM harness connector.
3.Check harness continuity between ECM terminal 108 and ASCD brake switch terminal 2.
Refer to Wiring Diagram.
Continuity should exist.
4.Also check harness for short to ground and short to power.
OK or NG
OK- GO TO 5.
NG- Repair open circuit or short to ground or short to power in harness or connectors.

5. CHECK ASCD BRAKE SWITCH

.
OK or NG
OK- GO TO 6.
NG- Replace ASCD brake switch.

6. CHECK INTERMITTENT INCIDENT

How to Check Terminal and Intermittent Incident.
-INSPECTION END


Component Inspection


ASCD BRAKE SWITCH

1.Turn ignition switch OFF.
2.Disconnect ASCD brake switch harness connector.





3.Check harness continuity between ASCD brake switch terminals
1 and 2 under the following conditions.





If NG, adjust ASCD brake switch installation, Adjustments, and perform step 3 again.