Diagnosis Procedure

ASCD BRAKE SWITCH


Diagnosis Procedure

1.CHECK OVERALL FUNCTION-I
With CONSULT-III
1. Turn ignition switch ON.
2. Select "BRAKE SW1" in "DATA MONITOR" mode with CONSULT-III.
3. Check "BRAKE SW1" indication under the following conditions.





Without CONSULT-III
1. Turn ignition switch ON.





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





OK or NG
OK>> GO TO 2.
NG>> GO TO 3.
2.CHECK OVERALL FUNCTION-II
With CONSULT-III
Check "BRAKE SW2" indication in "DATA MONITOR" mode.





Without CONSULT-III
Check voltage between ECM terminal 101 and ground under the following conditions.










OK or NG
OK >> INSPECTION END
NG>> GO TO 7.
3.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-III or tester.

Voltage: Battery voltage

OK or NG
OK>> GO TO 5.
NG>> GO TO 4.
4.DETECT MALFUNCTIONING PART
Check the following.
- Fuse block (J/B) connector E30
- 10 A fuse
- 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.
5.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 6.
NG>> Repair open circuit or short to ground or short to power in harness or connectors.
6.CHECK ASCD BRAKE SWITCH
Refer to Component Inspection.
OK or NG
OK>> GO TO 11.
NG>> Replace ASCD brake switch.
7.CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.





2. Disconnect stop lamp switch harness connector.
3. Check voltage between stop lamp switch terminal 1 and ground with CONSULT -II or tester.






Voltage: Battery voltage

OK or NG
OK>> GO TO 9.
NG>> GO TO 8.
8.DETECT MALFUNCTIONING PART
Check the following.
- Fuse block (J/B) connector E30
- 10 A fuse
- Harness for open or short between stop lamp switch and battery
- Repair open circuit or short to ground or short to power in harness or connectors.
9.CHECK STOP LAMP SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 101 and stop lamp switch terminal 2. Refer to Wiring Diagram.

Continuity should exist.

3. Also check harness for short to ground and short to power.
OK or NG
OK>> GO TO 10.
NG>> Repair open circuit or short to ground or short to power in harness or connectors.
10.CHECK STOP LAMP SWITCH
Refer to P1805.
OK or NG
OK>> GO TO 11.
NG>> Replace stop lamp switch.
11.CHECK INTERMITTENT INCIDENT
Refer to Description Diagnosis Procedure.
- INSPECTION END