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.
Key Switch (Intelligent Key Unit Input) Check
- CHECK KEY SWITCH
With CONSULT-III
Check key switch ("KEY SW") in "DATA MONITOR" mode with CONSULT-III.
CONSULT-III DESCRIPTIONMonitor item Condition KEY SW Insert mechanical key into ignition switch: ON Remove mechanical key from ignition switch: OFF Without CONSULT-III
- Turn ignition switch OFF.
- Disconnect Intelligent Key unit harness connector.
- Check voltage between Intelligent Key unit harness connector M42 terminal 7 and ground.VOLTAGE AND CONTINUITY SPECIFICATIONS
Connector Terminals Condition Voltage (V) (Approx.) (+) (-) M42 7 Ground Insert mechanical key into ignition switch Battery voltage Remove mechanical key from ignition switch 0 Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
OK: Key switch is OK.
NG: GO TO 2.
- CHECK KEY SWITCH POWER SUPPLY CIRCUIT
- Remove mechanical key from ignition switch.
- Disconnect key switch and ignition knob switch connector.
- Check voltage between key switch and ignition knob switch harness connector M49 terminal 2 and ground.
2 - Ground : Battery voltage
Fig 2: Checking Voltage Between Key Switch And Ignition Knob Switch Harness Connector M49 Terminal 2 And GroundCourtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
OK: GO TO 3.
NG: Repair or replace key switch and ignition knob switch power supply circuit.
- CHECK KEY SWITCH OPERATION
Check continuity between key switch and ignition knob switch terminals 1 and 2.
VOLTAGE AND CONTINUITY SPECIFICATIONSComponent Terminals Condition Continuity Key switch 1 2 Insert mechanical key into ignition switch. Yes Remove mechanical key from ignition switch. No Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
OK: GO TO 4.
NG: Replace key cylinder assembly (built-in key switch).
- CHECK KEY SWITCH CIRCUIT
- Check continuity between Intelligent Key unit harness connector M42 (A) terminal 7 and key switch and ignition knob switch harness connector M49 (B) terminal 1.
7 - 1 : Continuity should exist.
- Check continuity between Intelligent Key unit harness connector M42 (A) terminal 7 and ground.
7 - Ground : Continuity should not exist.
Fig 4: Checking Continuity Between Intelligent Key Unit Harness Connector M42 (A) Terminal 7 And GroundCourtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
OK: Check the condition of harness and harness connector.
NG: Repair or replace harness between Intelligent Key unit and key switch and ignition knob switch.
- Check continuity between Intelligent Key unit harness connector M42 (A) terminal 7 and key switch and ignition knob switch harness connector M49 (B) terminal 1.
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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