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 ASCD BRAKE SWITCH POWER SUPPLY CIRCUIT
- Turn ignition switch OFF.
- Disconnect ASCD brake switch harness connector.
- Turn ignition switch ON.
- Check the voltage between ASCD brake switch harness connector and ground.
VOLTAGE SPECIFICATIONASCD brake switch Ground Voltage Connector Terminal E109 1 Ground Battery voltage Is the inspection result normal?
YES: GO TO 3.
NO: GO TO 2.
- DETECT MALFUNCTIONING PART
Check the following.
- Fuse block (J/B) connector E103
- 10 A fuse (No. 3)
- Harness for open or short between ASCD brake switch and fuse
Repair open circuit or short to ground in harness or connectors.
- CHECK ASCD BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
- Turn ignition switch OFF.
- Disconnect ECM harness connector.
- Check the continuity between ASCD brake switch harness connector and ECM harness connector.CONTINUITY SPECIFICATION
ASCD brake switch ECM Continuity Connector Terminal Connector Terminal E109 2 M107 126 Existed - Also check harness for short to ground and short to power.
Is the inspection result normal?
YES: GO TO 5.
NO: GO TO 4.
- DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors E106, M6
- 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 (ASCD BRAKE SWITCH) "
Is the inspection result normal?
YES: GO TO 6.
NO: Replace ASCD brake switch.
- CHECK INTERMITTENT INCIDENT
Refer to "INTERMITTENT INCIDENT ".
INSPECTION END
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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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