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 DTC WITH ADAS CONTROL UNIT
Refer to "CONSULT FUNCTION (ICC/ADAS) " and "DTC INDEX ".
Are any DTCs detected?
YES: Perform the Diagnosis Procedure corresponding to the detected DTC.
NO: GO TO 2.
- CHECK OVERALL FUNCTION
WITH CONSULT
- Turn ignition switch ON.
- Select "BRAKE SW1" in "DATA MONITOR" mode with CONSULT.
- Check "BRAKE SW1" indication under the following conditions.
Monitor item Condition Indication BRAKE SW1 (ICC brake switch) Brake pedal Slightly depressed OFF Fully released ON
WITHOUT CONSULT
- Turn ignition switch ON.
- Check the voltage between ECM harness connector terminals under the following conditions.
ECM Condition Voltage (V) Connector + - Terminal Terminal E80 147 (ICC brake switch signal) 175 Brake pedal Slightly depressed Approx. 0 Fully released Battery voltage Is the inspection result normal?
YES: INSPECTION END
NO: GO TO 3.
- CHECK ICC BRAKE SWITCH POWER SUPPLY CIRCUIT-I
- Turn ignition switch OFF.
- Disconnect ICC brake switch harness connector.
- Turn ignition switch ON.
- Check the voltage between ICC brake switch harness connector and ground.
ICC brake switch Ground Voltage Connector Terminal E68 2 Ground Battery voltage Is the inspection result normal?
YES: GO TO 7.
NO: GO TO 4.
- CHECK ICC BRAKE SWITCH POWER SUPPLY CIRCUIT-II
Check the voltage between ICC brake switch harness connector and ground.
ICC brake switch Ground Voltage Connector Terminal E68 1 Ground Battery voltage Is the inspection result normal?
YES: GO TO 6.
NO: GO TO 5.
- DETECT MALFUNCTIONING PART
Check the following.
- Fuse block (J/B) connector E103
- 10 A fuse (No. 3)
- Harness for open or short between ICC brake switch and fuse
: Repair open circuit or short to ground in harness or connectors.
- CHECK ICC BRAKE SWITCH
Refer to "COMPONENT INSPECTION (ICC BRAKE SWITCH) ".
Is the inspection result normal?
YES: GO TO 9.
NO: Replace ICC brake switch. Refer to "REMOVAL AND INSTALLATION ".
- CHECK ICC BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
- Turn ignition switch OFF.
- Disconnect ECM harness connector.
- Check the continuity between ICC brake switch harness connector and ECM harness connector.
ICC brake switch ECM Continuity Connector Terminal Connector Terminal E68 2 E80 147 Existed - Also check harness for short to ground and short to power.
Is the inspection result normal?
YES: GO TO 9.
NO: GO TO 8.
- DETECT MALFUNCTIONING PART
Check the following.
- Harness for open or short between ICC brake switch and ECM
- Loose or poor connection for each connector and harness
: Repair open circuit, short to ground or short to power in harness or connectors.
- CHECK INTERMITTENT INCIDENT
Refer to "INTERMITTENT INCIDENT ".
: 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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