Toyota Tundra Service Manual: Windshield Deicer does not Operate

Toyota Tundra Service Manual / Vehicle Interior / Window / Glass / Windshield Deicer System / Windshield Deicer does not Operate

DESCRIPTION

When the air conditioning control assembly (windshield deicer switch) turns is turned on, a windshield deicer activation request signal is sent via the LIN communication line to the air conditioning amplifier. Then the air conditioning amplifier operates the windshield deicer.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

HINT:

This circuit uses the LIN communication line. Before performing the inspection, check that the LIN communication system is functioning normally (see page ).

NOTICE:

Inspect the fuses for circuits related to this system before performing the following procedure.

PROCEDURE

1.	PERFORM ACTIVE TEST USING TECHSTREAM (WINDSHIELD DEICER RELAY ASSEMBLY)

(a) Select the Active Test using the Techstream to generate a control command, and then check that the windshield deicer operates (See page ).

Air Conditioner

Tester Display	Test Part	Control Range	Diagnostic Note
Deicer Relay (Front)	Windshield deicer relay assembly	ON or OFF	-

OK:

Windshield deicer relay assembly turns ON and OFF.

GO TO STEP 3

2.	CHECK AIR CONDITIONING CONTROL ASSEMBLY

(a) Temporarily replace the air conditioning control assembly with a new or normally functioning one (See page ).

(b) Check that the malfunction disappears.

OK:

Malfunction disappears.

END (AIR CONDITIONING CONTROL ASSEMBLY IS DEFECTIVE)

REPLACE AIR CONDITIONING AMPLIFIER

3.	INSPECT WINDSHIELD DEICER RELAY ASSEMBLY (DEICER)

(a) Remove the windshield deicer relay assembly (DEICER) from the engine room relay block, junction block.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
3 - 5	When battery voltage is not applied between terminals 1 and 2	10 kΩ or higher
3 - 5	When battery voltage is applied to terminals 1 and 2	Below 1 Ω

REPLACE WINDSHIELD DEICER RELAY ASSEMBLY

4.	CHECK HARNESS AND CONNECTOR (DEICER RELAY - AIR CONDITIONING AMPLIFIER AND BATTERY)

*a	Component without relay connected (Engine Room Relay Block, Junction Block)

(a) Remove the windshield deicer relay assembly (DEICER) from the engine room relay block, junction block.

(b) Disconnect the J19 air conditioning amplifier connector.

Standard Voltage:

Tester Connection	Condition	Specified Condition
Windshield deicer relay assembly (DEICER) terminal 1 - Body ground	Ignition switch ON	11 to 14 V
	Ignition switch OFF	Below 1 V
Windshield deicer relay assembly (DEICER) terminal 3 - Body ground	Always	11 to 14 V

(d) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
Windshield deicer relay assembly (DEICER) terminal 2 - J19-40 (D)	Always	Below 1 Ω
Windshield deicer relay assembly (DEICER) terminal 2 or J19-40 (D) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.	CHECK HARNESS AND CONNECTOR (DEICER RELAY - WINDSHIELD DEICER WIRE)

(a) Remove the windshield deicer relay assembly (DEICER) from the engine room relay block, junction block.

(b) Disconnect the A23 windshield glass (windshield deicer wire) connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
Windshield deicer relay assembly (DEICER) terminal 5 - A23-1 (B)	Always	Below 1 Ω
Windshield deicer relay assembly (DEICER) terminal 5 or A23-1 (B) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

6.	CHECK HARNESS AND CONNECTOR (WINDSHIELD DEICER WIRE - BODY GROUND)

*a	Front view of wire harness connector (to Windshield Deicer Wire)

(a) Disconnect the windshield glass (windshield deicer wire) connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A23-2 (E) - Body ground	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

7.	CHECK HARNESS AND CONNECTOR (WINDSHIELD DEICER POWER SOURCE)

*a	Front view of wire harness connector (to Windshield Deicer Wire)

(a) Disconnect the windshield glass (windshield deicer wire) connector.

(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection	Condition	Specified Condition
A23-1 (B) - A23-2 (E)	Ignition switch ON, windshield deicer switch on	11 to 14 V
A23-1 (B) - A23-2 (E)	Ignition switch ON, windshield deicer switch off	Below 1 V

REPLACE WINDSHIELD GLASS

REPLACE AIR CONDITIONING AMPLIFIER

Terminals Of Ecu

Windshield Glass

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