Rear Window Defogger System Does Not Operate

WINDSHIELD / WINDOWGLASS: WINDOW DEFOGGER SYSTEM: Rear Window Defogger System does not Operate

Rear Window Defogger System does not Operate

DESCRIPTION

- The rear defogger & mirror heater switch on the multi-display inputs a request signal to the A/C amplifier (ECU). Then, the A/C amplifier turns ON the RR-DEF relay built into the power distributor in response to the input, thus switching ON the rear defogger. (The deicer and mirror heater also turn ON at the same time)
HINT: The power distributor is built into the J/B No.2.

- The RR-DEF relay is built into the J/B No.2. For inspection, use the terminals in the J/B No.2.

- If RR-DEF relay is malfunctioning , replace the J/B No.2.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. INSPECT COMMUNICATION LINE
(a) Use Techstream to check for normal function of the multiplex communication system.
(1) (ECU unconnected, communication line malfunctioning) Without DTC B1214, B1215 or B 1262 outputs, proceed to A.
(2) (ECU unconnected, communication line malfunctioning) With DTC B1214, B1215 or B 1262 outputs, proceed to B.
B -- GO TO MULTIPLEX COMMUNICATION SYSTEM
A -- Continue to next step.
2. INSPECT FUSE (HEATER, RR-DEF)
(a) Remove the HEATER fuse from the instrument panel J/B.
(b) Remove the RR-DEF fuse from the FL block.
(c) Check the resistance.
Standard resistance:
Below 1 Ohms
NG -- REPLACE FUSE
OK -- Continue to next step.
3. PERFORM ACTIVE TEST
(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch on.
(c) Perform the Active Test according to the display on the tester.

AIR CONDITIONER:

NG -- INSPECT JUNCTION BLOCK
OK -- Continue to next step.
4. CHECK AIR CONDITIONING SYSTEM OPERATE
NG -- GO TO AIR CONDITIONING SYSTEM
OK -- REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY
5. INSPECT JUNCTION BLOCK

(a) Check the voltage of the terminal of the J/B.
Standard voltage:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)
OK -- Continue to next step.
6. INSPECT JUNCTION BLOCK (MODE MONITOR TERMINAL)

(a) Check the voltage of the terminal to the following condition.

- Engine running.

- A/C switch is OFF.

- Rear defogger and deicer switch is ON.

Result:

B -- CHECK WIRE HARNESS (REAR WINDOW DEFOGGER - JUNCTION BLOCK NO.2)
A -- Continue to next step.
7. INSPECT JUNCTION BLOCK (RR-DEF RELAY)
(a) Remove the junction block No.2.

(b) Connect the battery positive (+) lead to terminal 2B-8 and battery negative (-) terminal lead to terminal 2H-12, 2B-7 and 2H-11.
(c) Check the voltage of the RR-DEF relay terminals.
Standard voltage:

(d) Connect another battery positive (+) lead to the terminal 2H-12.
(e) Check the voltage of the RR-DEF relay terminals.
Standard voltage:

NG -- REPLACE JUNCTION BLOCK
OK -- Continue to next step.
8. INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY

(a) Disconnect the A8 connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
9. INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY

(a) Connect the A8 connector.
(b) Connect Techstream to the DLC3.
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage:

HINT: *1: Perform the Active Test according to the display on the tester.

AIR CONDITIONER:

NG -- REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY
OK -- Continue to next step.
10. INSPECT REAR WINDOW DEFOGGER WIRE

NOTICE:
- When cleaning the glass, wipe the glass along the wire using a soft and dry cloth. Take care not to damage the wires.
- Do not use detergents or glass cleaners that have abrasive ingredients.
- When measuring voltage, wrap a piece of tin foil around the tip of the negative tester probe and press the foil against the wire with your finger, as shown in the illustration.

(a) Turn the ignition switch on.
(b) Turn the defogger switch ON.

HINT: If there is approximately 10 V, the wire may be broken between the center of the wire and the wire end on the battery side. If there is no voltage, the wire may be broken between the center of the wire and the end on the ground side.
(d) Place the voltmeter positive (+) lead against the defogger wire on the battery side.
(e) Place the voltmeter negative (-) lead with the foil strip against the wire on the ground side.
(f) Slide the positive (+) lead from the battery side to the ground side.
(g) The point where the voltage drops from approximately 10 V to 0 V is where the defogger wire is broken.
HINT: If the defogger wire is not broken, the voltmeter indicates 0 V at the positive (+) end of the defogger wire but gradually increases to approximately 12 V as the meter probe moves to the other end.

NG -- REPAIR REAR WINDOW DEFOGGER WIRE
OK -- Continue to next step.
11. CHECK WIRE HARNESS (REAR WINDOW DEFOGGER - JUNCTION BLOCK NO.2)

(a) Disconnect the N4, N5 defogger and 2B J/B connectors.
(b) Check the resistance of the wire harness side connectors.
Standard resistance:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE NOISE FILTER
12. CHECK WIRE HARNESS (REAR WINDOW DEFOGGER - JUNCTION BLOCK NO.2)

(a) Disconnect the N4, N5 defogger and 2B J/B connectors.
(b) Check the resistance of the wire harness side connectors.
Standard resistance:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
13. INSPECT JUNCTION BLOCK (RR-DEF RELAY)
(a) Remove the junction block No.2.

(d) Connect another battery positive (+) lead to the terminal 2H-12.
(e) Check the voltage of the RR-DEF relay terminals.
Standard voltage:

NG -- REPLACE JUNCTION BLOCK
OK -- REPLACE NOISE FILTER