Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Diagnosis Procedure
- CHECK OVERALL FUNCTION-I
With CONSULT-III
- Turn ignition switch ON.
- Select "BRAKE SW1" in "DATA MONITOR" mode with CONSULT-III.
- Check "BRAKE SW1" indication under the following conditions.
INDICATION CONDITION CHARTCONDITION INDICATION Brake pedal: Fully released ON Brake pedal: Slightly depressed OFF Without CONSULT-III
- Turn ignition switch ON.
- Check voltage between ECM terminal 108 and ground under the following conditions.
VOLTAGE CONNECTOR TERMINALS REFERENCE CHARTCONDITION VOLTAGE Brake pedal: Fully released Battery voltage Brake pedal: Slightly depressed Approximately 0 V OK or NG
OK: INSPECTION END
NG: GO TO 2.
- CHECK ASCD BRAKE SWITCH POWER SUPPLY CIRCUIT
- Turn ignition switch OFF.
- Disconnect ASCD brake switch (2) harness connector.
- Stop lamp switch (1)
- Turn ignition switch ON.
- Check voltage between ASCD brake switch terminal 1 and ground with CONSULT-III or tester.
Voltage: Battery voltage
OK or NG
OK: GO TO 4.
NG: GO TO 3.
- DETECT MALFUNCTIONING PART
Check the following.
- Fuse block (J/B) connector E102
- 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.
- CHECK ASCD BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
- Turn ignition switch OFF.
- Disconnect ECM harness connector.
- Check harness continuity between ECM terminal 108 and ASCD brake switch terminal 2.
Refer to SYSTEM WIRING DIAGRAMS article.
Continuity should exist .
- Also check harness for short to ground and short to power.
OK or NG
OK: GO TO 6.
NG: GO TO 5.
- DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors E108, M15
- 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.
- CHECK ASCD BRAKE SWITCH
Refer to "COMPONENT INSPECTION "
OK or NG
OK: GO TO 7.
NG: Replace ASCD brake switch.
- CHECK INTERMITTENT INCIDENT
Refer to "DIAGNOSIS PROCEDURE ".
INSPECTION END
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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