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 ICC SENSOR INTEGRATED UNIT
Refer to "DIAGNOSIS DESCRIPTION ".
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 as per 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 as per the following conditions:
ECM Condition Voltage (V) Connector + - Terminal Terminal M107 117 (ICC brake switch signal) 128 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 E114 1 Ground Battery voltage Is the inspection result normal?
YES: GO TO 10.
NO: GO TO 4.
- CHECK ICC BRAKE SWITCH POWER SUPPLY CIRCUIT-II
- Turn ignition switch OFF.
- Disconnect ICC brake hold relay.
- Turn ignition switch ON.
- Check the voltage between ICC brake hold relay harness connector and ground.
ICC brake hold relay Ground Voltage Connector Terminal E91 3 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 hold relay and fuse
: Repair open circuit or short to ground in harness or connectors.
- CHECK ICC BRAKE SWITCH POWER SUPPLY CIRCUIT-III
- Turn ignition switch OFF.
- Check the continuity between ICC brake switch harness connector and ICC brake hold relay harness connector.
ICC brake switch ICC brake hold relay Continuity Connector Terminal Connector Terminal E114 1 E91 4 Existed - Also check harness for short to ground and short to power.
Is the inspection result normal?
YES: GO TO 7.
NO: Repair open circuit, short to ground or short to power in harness or connectors.
- CHECK ICC BRAKE HOLD RELAY CONTROL CIRCUIT FOR OPEN AND SHORT
- Turn ignition switch OFF.
- Disconnect brake booster control unit harness connector.
- Check the continuity between ICC brake hold relay harness connector and brake booster control unit harness connector.
ICC brake hold relay Brake booster control unit Continuity Connector Terminal Connector Terminal E91 1 B249 47 Existed - Check the continuity between ICC brake hold relay harness connector and ground.
ICC brake hold relay Ground Continuity Connector Terminal E91 2 Ground 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 connectors E106, M6
- Harness connectors M117, B201
- Harness for open or short between ICC brake hold relay and brake booster control unit
- Harness for open or short between ICC brake hold relay and ground
: Repair open circuit, short to ground or short to power in harness or connectors.
- CHECK ICC BRAKE HOLD RELAY
Refer to "COMPONENT INSPECTION (ICC BRAKE HOLD RELAY) ".
Is the inspection result normal?
YES: GO TO 13.
NO: Replace ICC brake hold relay.
- 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 E114 2 M107 126 Existed - Also check harness for short to ground and short to power.
Is the inspection result normal?
YES: GO TO 12.
NO: GO TO 11.
- DETECT MALFUNCTIONING PART
Check the Following:
- Harness connectors E106, M6
- Harness for open or short between ICC brake switch and ECM
: Repair open circuit, short to ground or short to power in harness or connectors.
- CHECK ICC BRAKE SWITCH
Refer to "COMPONENT INSPECTION (ICC BRAKE SWITCH) ".
Is the inspection result normal?
YES: GO TO 13.
NO: Replace ICC brake switch. Refer to "REMOVAL AND INSTALLATION ".
- CHECK INTERMITTENT INCIDENT
Perform "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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