Ignition Knob Switch Check

WARNING: This page is about a different car, the 2008 Infiniti QX56. However, it is still accessible from the selected car via links, so may be relevant.

CHECK IGNITION KNOB SWITCH

With CONSULT-III

Display "PUSH SW" on DATA MONITOR screen, and check if ON/OFF display is linked to ignition switch operation.

DATA MONITOR

Monitor item	Condition
PUSH SW	Ignition switch is pushed: ON
PUSH SW	Ignition switch is released: OFF

Without CONSULT-III

Turn ignition switch OFF.
Disconnect Intelligent Key unit connector.

Check voltage between Intelligent Key unit harness connector M70 terminal 27 and ground.

VOLTAGE SPECIFICATION

Connector	Terminals		Condition	Voltage (V) (Approx.)
Connector	(+)	(-)	Condition	Voltage (V) (Approx.)
M70	27	Ground	Ignition switch is pushed	Battery voltage
M70	27	Ground	Ignition switch is released	0

Fig 1: Checking Voltage Between Intelligent Key Unit Harness Connector M70 Terminal 27 And Ground

Is the inspection result normal?

YES: Ignition knob switch is OK.

NO: GO TO 2

CHECK IGNITION KNOB SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect key switch and ignition knob switch connector.
3. Check voltage between key switch and ignition knob switch harness connector M12 terminal 1 and ground.
  1 - Ground : Battery voltage
  
  Fig 2: Checking Voltage Between Key Switch And Ignition Knob Switch Harness Connector M12 Terminal 1 And Ground
Is the inspection result normal?

YES: GO TO 3

NO: Repair or replace key switch and ignition knob switch power supply circuit.

CHECK IGNITION KNOB SWITCH OPERATION

Check continuity between key switch and ignition knob switch terminals 1 and 2.

CONTINUITY SPECIFICATION

Component	Terminals		Condition	Continuity
Ignition knob switch	1	2	Ignition switch is pushed	Yes
Ignition knob switch	1	2	Ignition switch is released	No

Fig 3: Checking Continuity Between Key Switch And Ignition Knob Switch Terminals 1 And 2

Is the inspection result normal?

YES: GO TO 4

NO: Replace key switch and ignition knob switch.

CHECK IGNITION KNOB SWITCH CIRCUIT
1. Check continuity between Intelligent Key unit harness connector (A) M70 terminal 27 and key switch and ignition knob switch harness connector (B) M12 terminal 2.
  27 - 2 : Continuity should exist.
2. Check continuity between Intelligent Key unit harness connector M70 terminal 27 and ground.
  27 - Ground : Continuity should not exist.
  
  Fig 4: Checking Continuity Between Intelligent Key Unit Harness Connector M70 Terminal 27 And Ground
Is the inspection result normal?

YES: Check the condition of harness and harness connector.

NO: Repair or replace harness between Intelligent Key unit and key switch and ignition knob switch.