LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Suzuki >> 2012 >> Equator Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine General Information & Diagnosis - Qr25DE (4 Of 5) >> DTC P1572: ASCD Brake Switch >> Diagnosis Procedure >> M/T Models
April 5, 2026: LEMON Manuals is launched! Read the announcement.

M/T Models

DIAGNOSIS PROCEDURE

Step Action YES NO
1  CHECK OVERALL FUNCTION-I 
  1. 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.
G06444306G06444307G06444308Courtesy of SUZUKI OF AMERICA CORP.SUZUKI OF AMERICA CORP.SUZUKI OF AMERICA CORP.

  1. 2) Without SDT
    1. Turn ignition switch ON.
    2. Check voltage between ECM terminal 108 and ground under the following conditions.
G06444306G06444307G06444308Courtesy of SUZUKI OF AMERICA CORP.SUZUKI OF AMERICA CORP.SUZUKI OF AMERICA CORP.
G06444306G06444307G06444308Courtesy of SUZUKI OF AMERICA CORP.SUZUKI OF AMERICA CORP.SUZUKI OF AMERICA CORP.

OK or NG 		 GO TO 2. GO TO 3.
2  CHECK OVERALL FUNCTION-II 
  1. With SDT 

    Check "BRAKE SW2" indication in "Data list" mode.

  2. Without SDT 

    Check voltage between ECM terminal 101 and ground under the following conditions.


OK or NG 		 GO TO 14. GO TO 10.
3  CHECK ASCD BRAKE SWITCH CIRCUIT 
  1. Turn ignition switch OFF.
  2. Disconnect ASCD clutch switch harness connector.
G06444309G06444310G06444311Courtesy of SUZUKI OF AMERICA CORP.SUZUKI OF AMERICA CORP.SUZUKI OF AMERICA CORP.

  1. 3. Turn ignition switch ON.
  2. 4. Check voltage between ASCD clutch switch terminal 1 and ground under the following conditions with SDT or tester.
G06444309G06444310G06444311Courtesy of SUZUKI OF AMERICA CORP.SUZUKI OF AMERICA CORP.SUZUKI OF AMERICA CORP.
G06444309G06444310G06444311Courtesy of SUZUKI OF AMERICA CORP.SUZUKI OF AMERICA CORP.SUZUKI OF AMERICA CORP.

OK or NG 		 GO TO 8. GO TO 4.
4  CHECK ASCD BRAKE SWITCH POWER SUPPLY CIRCUIT 
  1. Turn ignition switch OFF.
  2. Disconnect ASCD brake switch harness connector.
G06444312G06444313Courtesy of SUZUKI OF AMERICA CORP.SUZUKI OF AMERICA CORP.

  1. 3. Turn ignition switch ON.
  2. 4. Check voltage between ASCD brake switch terminal 1 and ground with SDT or tester.
G06444312G06444313Courtesy of SUZUKI OF AMERICA CORP.SUZUKI OF AMERICA CORP.

Voltage: Battery voltage 
OK or NG 		 GO TO 6. GO TO 5.
5  DETECT MALFUNCTIONING PART 
Check the following.
  • Fuse block (J/B) connector E160
  • 10A 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.  
6  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 .

    Continuity should exist. 

  3. Also check harness for short to ground and short to power.

OK or NG 		 GO TO 7. Repair open circuit, short to ground or short to power in harness or connectors.
7  CHECK ASCD BRAKE SWITCH 
Refer to [P1572 ASCD BRAKE SWITCH ].
OK or NG 		 GO TO 14. Replace ASCD brake switch.
8  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 .

    Continuity should exist. 

  4. Also check harness for short to ground and short to power.

OK or NG 		 GO TO 9. Repair open circuit, short to ground or short to power in harness or connectors.
9  CHECK ASCD CLUTCH SWITCH 
Refer to [P1572 ASCD BRAKE SWITCH ].
OK or NG 		 GO TO 14. Replace ASCD clutch switch.
10  CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT 
  1. Turn ignition switch OFF.
  2. Disconnect stop lamp switch harness connector.
G06444314G06444315Courtesy of SUZUKI OF AMERICA CORP.SUZUKI OF AMERICA CORP.

  1. 3. Check voltage between stop lamp switch terminal 1 and ground with SDT or tester.

    Voltage: Battery voltage 

G06444314G06444315Courtesy of SUZUKI OF AMERICA CORP.SUZUKI OF AMERICA CORP.

OK or NG 		 GO TO 12. GO TO 11.
11  DETECT MALFUNCTIONING PART 
Check the following.
  • Fuse block (J/B) connector E160
  • 10A fuse (No. 20)
  • Harness for open or short between stop lamp switch and fuse
 Repair open circuit, short to ground or short to power in harness or connectors.  
12  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 		 GO TO 13. Repair open circuit, short to ground or short to power in harness or connectors.
13  CHECK STOP LAMP SWITCH 
Refer to [P1572 ASCD BRAKE SWITCH ].
OK or NG 		 GO TO 14. Replace stop lamp switch.
14  CHECK INTERMITTENT INCIDENT 
Refer to [SERVICE INFORMATION FOR ELECTRICAL INCIDENT: INTERMITTENT INCIDENT ]		 INSPECTION END   
scientia non olet · About LEMON Manuals