Diagnosis Procedure

1. Push the ignition switch to ON.
2. Check that an operation noise of rear window defogger relay [located in fuse block (J/B)] can be heard when pressing the rear window defogger switch ON and OFF.

Is the inspection result normal-

YES

GO TO 2 .

NO

GO TO 5 .

Check if the following fuse in fuse block (J/B) is blown.

Is the inspection result normal-

YES

GO TO 3 .

NO

Replace the blown fuse after repairing the affected circuit.

1. Connect a voltmeter between fuse block (J/B) and ground.
2. While pressing the rear window defogger switch ON and OFF, check for voltage between fuse block (J/B) and ground.

   (+)		(-)	Condition		Voltage (V) (Approx.)
   Fuse block (J/B)
   Connector	Terminal
   M4	5P	Ground	Rear window defogger switch	ON	Battery voltage
   				OFF	0

Is the inspection result normal?

YES

GO TO 4 .

NO

Perform rear window defogger relay diagnosis. Refer to Diagnosis Procedure .

1. Press rear window defogger switch.
2. Check for voltage between A/C auto amp. connector and ground.

   (+)		(-)	Condition		Voltage (V) (Approx.)
   A/C auto amp.
   Connector	Terminal
   M137	35	Ground	Rear window defogger switch	ON	Battery voltage
   				OFF	0

Is the inspection result normal-

YES

Replace A/C auto amp. Refer to Removal and Installation .

NO

Repair or replace harness.

CONSULT

1. Select "REAR DEFOGGER" of "BCM".
2. Select "REAR DEF SW" in "Data Monitor" mode.
3. Check that the function operates normally according to the following conditions:

Is the inspection result normal-

YES

GO TO 8 .

NO

GO TO 6 .

Check voltage between BCM connector and ground.

Is the inspection result normal-

YES

Replace BCM. Refer to Removal and Installation .

NO

GO TO 7 .

1. Push ignition switch to OFF.
2. Disconnect BCM and front air control.
3. Check continuity between BCM connector and A/C auto amp.

   BCM		A/C auto amp.		Continuity
   Connector	Terminal	Connector	Terminal
   M18	32	M137	15	Yes

4. Check continuity between BCM harness connector and ground.

   BCM		Ground	Continuity
   Connector	Terminal
   M18	32		No

Is the inspection result normal-

YES

Replace A/C auto amp. Refer to Removal and Installation .

NO

Repair or replace harness.

CONSULT

1. Select "REAR DEFOGGER" of "BCM."
2. Select "REAR DEFOGGER" in "Active Test" mode.
3. Touch "On".
4. Check voltage between fuse block (J/B) connector and ground.

   (+)		(-)	Condition		Voltage (V) (Approx.)
   Fuse block (J/B)
   Connector	Terminal
   M4	6P	Ground	Rear window defogger active test	ON	0
   				OFF	Battery voltage

Is the inspection result normal-

YES

GO TO 11 .

NO

GO TO 9 .

Check voltage between fuse block (J/B) connector and ground.

Is the inspection result normal-

YES

Replace rear window defogger relay.

NO

GO TO 10 .

1. Push ignition switch to OFF.
2. Disconnect BCM and fuse block (J/B).
3. Check continuity between BCM connector and fuse block (J/B) connector.

   BCM		Fuse block (J/B)		Continuity
   Connector	Terminal	Connector	Terminal
   M19	61	M4	6P	Yes

4. Check continuity between fuse block (J/B) connector and ground.

Is the inspection result normal-

YES

Perform rear window defogger relay component inspection. Refer to Component Inspection . If OK, replace BCM. Refer to Removal and Installation .

NO

Repair or replace harness.

Check rear window defogger relay-2.

Refer to Component Inspection .

Is the inspection result normal-

YES

GO TO 12 .

NO

Replace rear window defogger relay-2.

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.