Diagnosis Procedure

WARNING: This page is about a different car, the 2009 Nissan Maxima. However, it is still accessible from the selected car via links, so may be relevant.

CHECK REAR WINDOW DEFOGGER RELAY GROUND CIRCUIT

Turn ignition switch ON.
Check voltage between BCM connector and ground.

TERMINAL VOLTAGE REFERENCE CHART

Terminals			Condition of rear window defogger switch	Voltage (V) (Approx.)
(+)		(-)
BCM connector	Terminal
M18	59	Ground	ON	0
			OFF	Battery voltage

Fig 1: Checking Voltage Between BCM Connector And Ground

Courtesy of NISSAN MOTOR CO., U.S.A.

Is the inspection result normal?

YES: Rear window defogger relay power supply circuit is OK.

NO: GO TO 2

CHECK HARNESS CONTINUITY

Turn ignition switch OFF.
Disconnect BCM and fuse block (J/B).

Check continuity between BCM connector (A) and fuse block (J/B) connector (B).

TERMINAL CONTINUITY REFERENCE CHART

BCM connector	Terminal	Fuse block (J/B) connector	Terminal	Continuity
M18 (A)	59	M4 (B)	4Q	Yes

Fig 2: Checking Continuity Between BCM Connector And Fuse Block (J/B) Connector

Courtesy of NISSAN MOTOR CO., U.S.A.

Check continuity between BCM connector (A) and ground.

TERMINAL CONTINUITY REFERENCE CHART

BCM connector	Terminal	Ground	Continuity
M18 (A)	59	Ground	No

Is the inspection result normal?

YES: GO TO 3

NO: Repair or replace harness.

CHECK REAR WINDOW DEFOGGER RELAY
Check rear window defogger relay.

Refer to "COMPONENT INSPECTION ".

Is the inspection result normal?

YES: GO TO 4

NO: Replace rear window defogger relay.
CHECK INTERMITTENT INCIDENT
Check intermittent incident.

Refer to "INTERMITTENT INCIDENT ".

Is the inspection result normal?

YES: Check the following.
- Battery power supply circuit.
- Fuse block (J/B).
NO: Repair or replace the malfunctioning parts.