Toyota Tundra Service Manual: No Answer-Back

Toyota Tundra Service Manual / Vehicle Interior / Door Lock / Wireless Door Lock Control System / No Answer-Back

DESCRIPTION

In some cases, wireless door lock control functions are normal but the hazard warning light and/or wireless door lock buzzer answer-back function(s) does not operate. In such cases, hazard warning light and wireless door lock buzzer signal outputs from the main body ECU (multiplex network body ECU) may be malfunctioning.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

The wireless door lock control system uses the CAN communication system. First, confirm that there is no malfunction in the CAN communication system. Refer to the How to Proceed with Troubleshooting procedure.

Click here

PROCEDURE

1.	READ VALUE USING TECHSTREAM (ANSWER-BACK OPERATION)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Enter the following menus: Customize Setting / Wireless Door Lock.

(e) Select the setting by referring to the table below.

Wireless Door Lock

Display (Item)	Default	Content	Setting
Hazard Answer Back	ON	When LOCK switch on transmitter pressed, all hazard warning lights illuminate once. When UNLOCK switch pressed, all hazard warning lights illuminate twice	ON/OFF
Wireless Buzzer Resp	ON	Function that makes wireless buzzer sound for answer-back when transmitter LOCK/UNLOCK switch pressed	ON/OFF
Wireless Buzzer Vol	Level5	Wireless door lock buzzer volume	Level7/Level6/Level5/Level4/Level3/Level2/Level1/Level0

Either item is OFF or Level 0

PERFORM CUSTOMIZE FUNCTION

Both items are ON and except Level 0

2.	CHECK WIRELESS DOOR LOCK CONTROL FUNCTIONS

(a) Check the wireless door lock control function using the door control transmitter assembly.

Wireless door lock/unlock does not operate normally.

GO TO PROBLEM SYMPTOMS TABLE

Wireless door lock/unlock operates normally.

3.	READ VALUE USING TECHSTREAM (DOOR UNLOCK DETECTION SWITCH)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Enter the following menus: Body Electrical / Main Body / Data List.

(e) Read the Data List according to the display on the Techstream.

Main Body

Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
FL Door Lock Pos	Driver side door unlock detection switch signal/ON or OFF	ON: Driver side door is unlocked OFF: Driver side door is locked	-
FR Door Lock Pos	Front passenger side door unlock detection switch signal/ON or OFF	ON: Front passenger side door is unlocked OFF: Front passenger side door is locked	-
RL-Door Lock Pos SW	Rear door lock position switch signal/ON or OFF	ON: Either of rear door LH or rear door RH is unlocked OFF: Both of rear door LH and rear door RH are locked	-
RR-Door Lock Pos SW	Rear door lock position switch signal/ON or OFF	ON: Either of rear door LH or rear door RH is unlocked OFF: Both of rear door LH and rear door RH are locked	-

OK:

The Techstream should display as shown in the table according to door lock operation.

Result	Proceed to
OK	A
NG	B

GO TO LIGHTING SYSTEM (Proceed to Door Unlock Detection Switch Circuit)

4.	CHECK WIRELESS ANSWER-BACK OPERATION

(a) Check the wireless answer-back operation using the door control transmitter assembly.

Only hazard warning light answer-back does not occur.

GO TO STEP 10

Only wireless door lock buzzer answer-back does not occur.

5.	PERFORM ACTIVE TEST USING TECHSTREAM (WIRELESS DOOR LOCK BUZZER)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Enter the following menus: Body Electrical / Main Body / Active Test.

(e) Perform the Active Test according to the display on the Techstream.

Main Body

Tester Display	Test Part	Control Range	Diagnostic Note
Wireless Buzzer	Wireless door lock buzzer	ON/OFF	-

Wireless door lock buzzer turns on/off.

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

Wireless door lock buzzer does not turn on/off.

6.	CHECK HARNESS AND CONNECTOR (WIRELESS DOOR LOCK BUZZER - DRIVER SIDE JUNCTION BLOCK ASSEMBLY)

(a) Disconnect the A65 wireless door lock buzzer connector.

(b) Disconnect the 3H driver side junction block assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A65-1 (B) - 3H-29	Always	Below 1 Ω
A65-2 (E) - Body ground	Always	Below 1 Ω
A65-1 (B) or 3H-29 - Other terminals and body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

7.	CHECK DRIVER SIDE JUNCTION BLOCK ASSEMBLY

(a) Remove the main body ECU (multiplex network body ECU) from driver side junction block assembly.

Click here

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
3H-29 - A-21 (BZR)	Always	Below 1 Ω

*a	Component without harness connected (Driver Side Junction Block Assembly)

REPLACE DRIVER SIDE JUNCTION BLOCK ASSEMBLY

8.	REPLACE WIRELESS DOOR LOCK BUZZER

(a) Temporarily replace the wireless door lock buzzer with a new one.

Click here

9.	CHECK WIRELESS DOOR LOCK BUZZER OPERATION

(a) Check the operation of the wireless answer-back function.

OK:

Wireless answer-back function operates normally.

END (WIRELESS DOOR LOCK BUZZER WAS DEFECTIVE)

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

10.	CHECK HAZARD WARNING LIGHTS OPERATION

(a) Check that the hazard warning light blinks when the hazard warning signal switch is pressed.

OK:

Hazard warning light signal is normally.

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

GO TO LIGHTING SYSTEM (Proceed to Hazard Warning Switch Circuit)

How To Proceed With Troubleshooting

Only Wireless Control Function is Inoperative

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Toyota Tundra Service Manual: No Answer-Back

How To Proceed With Troubleshooting

Only Wireless Control Function is Inoperative

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