ASCD Brake Switch Circuit Check
ASCD Brake Switch Circuit Check
Component Description
When depress on the brake pedal, ASCD brake switch is turned OFF and stop lamp switch is turned ON. ECM detects the state of the brake pedal by this those two types of input (ON/OFF signal)
Refer to [Brake Pedal: Exploded View] ASCD System Description for the ASCD function.
Diagnosis Procedure
A/T Models
1. CHECK OVERALL FUNCTION-I
With SDT
1 Turn ignition switch ON.
2 Select "BRAKE SW1" in "Data list" mode with SDT.
3 Check "BRAKE SW1" indication under the following conditions.
Without SDT
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 SDT or tester.
OK or NG
OK
GO TO 4.
NG
GO TO 3.
3. DETECT MALFUNCTIONING PART
Check the following.
- Fuse block (J/B) connector E160
- 10 A fuse (No.12)
- Harness for open or short between ASCD brake switch and fuse
Repair open circuit or short to ground 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.
4 Also check harness for short to ground and short to power.
OK or NG
OK
GO TO 5.
NG
Repair open circuit, short to ground or short to power in harness or connectors.
5. CHECK ASCD BRAKE SWITCH
Refer to "Component Inspection".
OK or NG
OK
GO TO 6.
NG
Replace ASCD brake switch. Refer to Brake Pedal Exploded View.
6. CHECK INTERMITTENT INCIDENT
Refer to [Service Information for Electrical Incident: Intermittent Incident] Service Information for Electrical Incident: Intermittent Incident.
INSPECTION END
M/T Models
1. CHECK OVERALL FUNCTION-I
With SDT
1 Turn ignition switch ON.
2 Select "BRAKE SW1" in "Data list" mode with SDT.
3 Check "BRAKE SW1" indication under the following conditions.
Without SDT
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 CIRCUIT
1 Turn ignition switch OFF.
2 Disconnect ASCD clutch switch harness connector.
3 Turn ignition switch ON.
4 Check voltage between ASCD clutch switch terminal 1 and ground under the following conditions with SDT or tester.
OK or NG
OK
GO TO 7.
NG
GO TO 3.
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 SDT or tester.
OK or NG
OK
GO TO 5.
NG
GO TO 4.
4. DETECT MALFUNCTIONING PART
Check the following.
- Fuse block (J/B) connector E160
- 10 A fuse (No.12)
- Harness for open or short between ASCD brake switch and fuse
Repair open circuit, 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 Check harness continuity between ASCD brake switch terminal 2 and ASCD clutch switch terminal 1.
Refer to Wiring Diagram.
3 Also check harness for short to ground and short to power.
OK or NG
OK
GO TO 6.
NG
Repair open circuit, short to ground or short to power in harness or connectors.
6. CHECK ASCD BRAKE SWITCH
Refer to [P1572 ASCD Brake Switch] P1572.
OK or NG
OK
GO TO 9.
NG
Replace ASCD brake switch. Refer to [Brake Pedal: Exploded View] Brake Pedal Exploded View.
7. CHECK ASCD CLUTCH 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 clutch switch terminal 2.
Refer to Wiring Diagram.
4 Also check harness for short to ground and short to power.
OK or NG
OK
GO TO 8.
NG
Repair open circuit, short to ground or short to power in harness or connectors.
8. CHECK ASCD CLUTCH SWITCH
Refer to [P1572 ASCD Brake Switch] P1572.
OK or NG
OK
GO TO 9.
NG
Replace ASCD clutch switch. Refer to [Clutch Pedal: Exploded View] Exploded View.
9. CHECK INTERMITTENT INCIDENT
Refer to [Service Information for Electrical Incident: Intermittent Incident] Service Information for Electrical Incident: Intermittent Incident.
INSPECTION END
Component Inspection
ASCD Brake Switch
1) Turn ignition switch OFF.
2) Disconnect ASCD brake switch harness connector.
3) Check continuity between ASCD brake switch terminals 1 and 2 under the following conditions.
If NG, adjust ASCD brake switch installation, refer to [Clutch Pedal: On-Vehicle Inspection and Adjustment] Adjustments , and perform step 3 again.
ASCD Clutch Switch
1) Turn ignition switch OFF.
2) Disconnect ASCD clutch switch harness connector.
3) Check continuity between ASCD clutch switch terminals 1 and 2 under the following conditions.
If NG, adjust ASCD clutch switch installation, refer to Testing and Inspection , and perform step 3 again.