Diagnosis Procedure

WARNING: This page is about a different car, the 2020 Infiniti Q50. However, it is still accessible from the selected car via links, so may be relevant.

INSPECTION START
Perform inspection in accordance with procedure that confirms malfunction.

Which procedure confirms malfunction?

Component Function Check 1

GO TO 2.

Component Function Check 2

GO TO 5.
CHECK HORN FUNCTION
Check horn function using horn switch.

Do the horn sound?

YES

GO TO 3.

NO

Check horn circuit. Refer to Wiring Diagram .

CHECK HORN RELAY 1 CONTROL SIGNAL

Turn ignition switch ON.
Select "VEHICLE SECURITY HORN" in "ACTIVE TEST" mode of "THEFT ALM" of "BCM" using CONSULT.

Check voltage between IPDM E/R harness connector and ground.

(+)		(-)	Test item		Voltage
IPDM E/R
Connector	Terminal
E121	23	Ground	VEHICLE SECURITY HORN	On	0 - 1 V
				Off	9 - 16 V

Is the operation normal?

YES

GO TO 11.

GO TO 4.

CHECK HORN RELAY 1 CONTROL SIGNAL CIRCUIT

Disconnect IPDM E/R connector and horn relay 1 connector.

Check continuity between IPDM E/R harness connector and horn relay 1 harness connector.

IPDM E/R		Horn relay 1		Continuity
Connector	Terminal	Connector	Terminal	Continuity
E121	23	E102	2	Existed

Check continuity between IPDM E/R harness connector and ground.

IPDM E/R		Ground	Continuity
Connector	Terminal
E121	23		Not existed

Is the inspection result normal?

YES

Replace IPDM E/R. Refer to IPDM E/R : Removal & Installation .

Repair or replace harness.

CHECK HORN RELAY 2 CONTROL SIGNAL

Turn ignition switch ON.
Select "VEHICLE SECURITY HORN" in "ACTIVE TEST" mode of "THEFT ALM" of "BCM" using CONSULT.

Check voltage between IPDM E/R harness connector and ground.

(+)		(-)	Test item		Voltage
IPDM E/R
Connector	Terminal
E121	22	Ground	VEHICLE SECURITY HORN	On	0 - 1 V
				Off	9 - 16 V

Is the operation normal?

YES

GO TO 11.

GO TO 6.

CHECK HORN RELAY 2 POWER SUPPLY

Check voltage between horn relay 2 harness connector and ground.

(+)		(-)	Voltage
Horn relay 2
Connector	Terminal
E101	1	Ground	Battery voltage

Is the inspection result normal?

YES

GO TO 7.

Check 10 A fuse [No. 65 located in the fuse block (J/B)].

Check harness for open or short between horn relay 2 and fuse.

CHECK HORN LOW CONTROL CIRCUIT

Disconnect IPDM E/R connector and horn relay 2 connector.

Check continuity between IPDM E/R harness connector and horn relay 2 harness connector.

IPDM E/R		Horn relay 2		Continuity
Connector	Terminal	Connector	Terminal	Continuity
E121	22	E101	2	Existed

Check continuity between IPDM E/R harness connector and ground.

IPDM E/R		Ground	Continuity
Connector	Terminal
E121	22		Not existed

Is the inspection result normal?

YES

GO TO 8.

Repair or replace harness.

CHECK HORN LOW CIRCUIT

Disconnect horn low connector.

Check continuity between horn relay 2 harness connector and horn low harness connector.

Horn relay 2		Horn low		Continuity
Connector	Terminal	Connector	Terminal	Continuity
E101	3	E247	1	Existed

Check continuity between horn relay 2 harness connector and ground.

Horn relay 2		Ground	Continuity
Connector	Terminal
E101	3		Not existed

Is the inspection result normal?

YES

GO TO 9.

Repair or replace harness.

CHECK HORN LOW GROUND CIRCUIT

Check continuity between horn low harness connector and ground.

Horn low		Ground	Continuity
Connector	Terminal
E247	2		Existed

Is the inspection result normal?

YES

GO TO 10.

Repair or replace harness.

CHECK HORN RELAY 2
Refer to Component Inspection .

Is the inspection result normal?

YES

Replace horn low.

NO

Replace horn relay 2.
CHECK INTERMITTENT INCIDENT
Check intermittent incident. Refer to Inspection .

INSPECTION END