Lexus NX: All Door Entry Lock/Unlock Functions and Wireless Functions do not Operate

DESCRIPTION

If the entry lock and wireless lock operations cannot be performed, there may be door control receiver malfunctions, wave interference or problems in the communication which is used for the entry and wireless function between the door control receiver and certification ECU (smart key ECU assembly).

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

1.	INSPECT AUXILIARY BATTERY VOLTAGE

(a) Measure the voltage of the auxiliary battery with the power switch off.

Standard voltage:

11 to 14 V

HINT:

It may be possible to tell whether the auxiliary battery is discharged by operating the horn.

If the voltage is below 11 V, recharge or replace the auxiliary battery before proceeding to the next step.

NEXT

2.	CHECK FOR DTC

(a) Open the driver door using the mechanical key built into the electrical key transmitter sub-assembly.

(b) Check for DTCs.

Body Electrical > Smart Access > Trouble Codes

Result	Proceed to
DTCs are not output	A
DTCs are output	B

B

GO TO DIAGNOSTIC TROUBLE CODE CHART

A

3.	CHECK DOOR AJAR WARNING

(a) When the doors are locked by operating the entry lock function with all doors closed, check that the door ajar warning operates.

HINT:

Warning function (door ajar warning)

Click here

Result	Proceed to
The wireless buzzer does not sound	A
The wireless buzzer sounds	B

B

GO TO LIGHTING SYSTEM (Proceed to Door Courtesy Switch Circuit)

A

4.	CHECK POWER DOOR LOCK CONTROL SYSTEM

(a) When the door control switch on the multiplex network master switch assembly is operated, check that the doors unlock and lock according to the switch operation.

Click here

Result	Proceed to
Power door lock function operates normally	A
Power door lock function does not operate normally	B

B

GO TO POWER DOOR LOCK CONTROL SYSTEM

A

5.	CHECK KEY DIAGNOSTIC MODE

(a) Check the following antennas in key diagnostic mode.

Body Electrical > Smart Access > Utility

Tester Display
Communication Check(Key Diag Mode)

(1) Check the electrical key antenna (for driver door): When the electrical key transmitter sub-assembly is brought within 0.7 to 1 m (2.30 to 3.28 ft.) of the front door outside handle assembly (for driver door), check that the wireless buzzer sounds. HINT: Select either channel 1 or channel 2 and inspect key diagnostic mode for each channel. If the buzzer sounds with [CH1] displayed but not with [CH2], the electrical key transmitter sub-assembly cannot be detected by channel 2 due to a malfunction, such as wave interference.

*a 0.7 to 1 m (2.30 to 3.28 ft.)

(2) Check the electrical key antenna (for front passenger door): When the electrical key transmitter sub-assembly is brought within 0.7 to 1 m (2.30 to 3.28 ft.) of the front door outside handle assembly (for front passenger door), check that the wireless buzzer sounds. HINT: Select either channel 1 or channel 2 and inspect key diagnostic mode for each channel. If the buzzer sounds with [CH1] displayed but not with [CH2], the electrical key transmitter sub-assembly cannot be detected by channel 2 due to a malfunction, such as wave interference.

*a 0.7 to 1 m (2.30 to 3.28 ft.)

(3) Check the electrical key antenna (for rear door (for driver side)): When the electrical key transmitter sub-assembly is brought within 0.7 to 1 m (2.30 to 3.28 ft.) of the rear door outside handle assembly (for driver side), check that the wireless buzzer sounds. HINT: Select either channel 1 or channel 2 and inspect key diagnostic mode for each channel. If the buzzer sounds with [CH1] displayed but not with [CH2], the electrical key transmitter sub-assembly cannot be detected by channel 2 due to a malfunction, such as wave interference.

*a 0.7 to 1 m (2.30 to 3.28 ft.)

(4) Check the electrical key antenna (for rear door (for front passenger side)): When the electrical key transmitter sub-assembly is brought within 0.7 to 1 m (2.30 to 3.28 ft.) of the rear door outside handle assembly (for front passenger side), check that the wireless buzzer sounds. HINT: Select either channel 1 or channel 2 and inspect key diagnostic mode for each channel. If the buzzer sounds with [CH1] displayed but not with [CH2], the electrical key transmitter sub-assembly cannot be detected by channel 2 due to a malfunction, such as wave interference.

*a 0.7 to 1 m (2.30 to 3.28 ft.)

(5) Check the No. 1 indoor electrical key antenna assembly (front floor): When the electrical key transmitter sub-assembly is at either inspection point, check that the wireless buzzer sounds. HINT: Select either channel 1 or channel 2 and inspect key diagnostic mode for each channel. If the buzzer sounds with [CH1] displayed but not with [CH2], the electrical key transmitter sub-assembly cannot be detected by channel 2 due to a malfunction, such as wave interference.

*a Inspection Point

(6) Check the No. 2 indoor electrical key antenna assembly (rear floor): When the electrical key transmitter sub-assembly is at either inspection point, check that the wireless buzzer sounds. HINT: Select either channel 1 or channel 2 and inspect key diagnostic mode for each channel. If the buzzer sounds with [CH1] displayed but not with [CH2], the electrical key transmitter sub-assembly cannot be detected by channel 2 due to a malfunction, such as wave interference.

*a Inspection Point

(7) Check the No. 3 indoor electrical key antenna assembly (inside luggage): When the electrical key transmitter sub-assembly is at either inspection point, check that the wireless buzzer sounds. HINT: Select either channel 1 or channel 2 and inspect key diagnostic mode for each channel. If the buzzer sounds with [CH1] displayed but not with [CH2], the electrical key transmitter sub-assembly cannot be detected by channel 2 due to a malfunction, such as wave interference.

*a Inspection Point

(8) Check the electrical key antenna (outside luggage compartment): When the electrical key transmitter sub-assembly is brought within 0.7 to 1 m (2.30 to 3.28 ft.) of the electrical key antenna (outside luggage compartment), check that the wireless buzzer sounds. HINT: Select either channel 1 or channel 2 and inspect key diagnostic mode for each channel. If the buzzer sounds with [CH1] displayed but not with [CH2], the electrical key transmitter sub-assembly cannot be detected by channel 2 due to a malfunction, such as wave interference. OK: Wireless buzzer sounds.

*a 0.7 to 1 m (2.30 to 3.28 ft.)

Result	Proceed to
Diagnostic mode inspections fail for both channels	A
Diagnostic mode inspections succeed for both channels	B
Diagnostic mode inspection succeeds for only one of the channels	C

B

GO TO STEP 18

C

GO TO STEP 27

A

6.	CHECK WAVE ENVIRONMENT

(a) Bring the electrical key transmitter sub-assembly that was checked first near the door control receiver and select the failed channel (the channel in which the buzzer did not sound) to recheck key diagnostic mode.

Click here

Result	Proceed to
The wireless buzzer does not sound	A
The wireless buzzer sounds	B

B

AFFECTED BY WAVE INTERFERENCE

A

7.	CHECK TRANSMITTER BATTERY

(a) Check the transmitter battery level of the electrical key transmitter sub-assembly that was checked first.

(1) Press and hold the lock switch of the transmitter for 5 seconds and check the number of times that the transmitter LED illuminates.

Result	Proceed to
Transmitter LED illuminates 3 times or more when switch is pressed and held	A
Transmitter LED does not illuminate when switch is pressed and held	B
Transmitter LED illuminates once or twice but not a third time	C

B

GO TO STEP 17

C

REPLACE TRANSMITTER BATTERY

A

8.	CHECK ELECTRICAL KEY TRANSMITTER SUB-ASSEMBLY

(a) Check if there is another electrical key transmitter sub-assembly available that is already registered to the vehicle.

Result	Proceed to
Another registered electrical key transmitter sub-assembly is not available	A
Another registered electrical key transmitter sub-assembly is available	B

B

GO TO STEP 10

A

9.	ELECTRICAL KEY TRANSMITTER SUB-ASSEMBLY REGISTRATION (NEW ELECTRICAL KEY TRANSMITTER SUB-ASSEMBLY)

(a) Register a new electrical key transmitter sub-assembly.

Click here

NEXT

10.	CHECK ENTRY LOCK OPERATION

(a) Using another registered electrical key transmitter sub-assembly, check that the entry lock and unlock functions operate.

Result	Proceed to
Entry function does not operate normally	A
Entry function operates normally	B

B

END (ELECTRICAL KEY TRANSMITTER SUB-ASSEMBLY WAS DEFECTIVE)

A

11.	CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - DOOR CONTROL RECEIVER AND BODY GROUND)

(a) Disconnect the I52 certification ECU (smart key ECU assembly) connector.

(b) Disconnect the P11 door control receiver connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
I52-18 (RCO) - P11-10 (+5)	Always	Below 1 Ω
I52-20 (RDAM) - P11-9 (DATA)	Always	Below 1 Ω
I52-19 (CSEL) - P11-6 (CSEL)	Always	Below 1 Ω
P11-12 (GND) - Body ground	Always	Below 1 Ω
I52-18 (RCO) or P11-10 (+5) - Body ground	Always	10 kΩ or higher
I52-20 (RDAM) or P11-9 (DATA) - Body ground	Always	10 kΩ or higher
I52-19 (CSEL) or P11-6 (CSEL) - Body ground	Always	10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

12.	CHECK ENTRY LOCK OPERATION

(a) Connect all connectors and check that the entry lock and unlock functions operate.

Click here

Result	Proceed to
Entry function does not operate normally	A
Entry function operates normally	B

B

END (CONNECTOR WAS NOT CONNECTED SECURELY)

A

13.	CHECK DOOR CONTROL RECEIVER

(a) Measure the resistance according to the value(s) in the table below. Standard Resistance: Tester Connection Condition Specified Condition P11-12 (GND) - Body ground Always Below 1 Ω

*a Component with harness connected (Door Control Receiver)

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
P11-9 (DATA) - P11-12 (GND)	Procedure: Power switch off All doors closed All doors locked Lock or unlock switch of electrical key transmitter sub-assembly pressed	Below 1 V → Pulse generation (See waveform 1)

(c) Using an oscilloscope, check waveform 1. NOTICE: The oscilloscope waveform shown in the illustration is an example for reference only. Noise, chattering, etc. are not shown. Waveform 1 (Reference) Item Content Tester Connection P11-9 (DATA) - P11-12 (GND) Tool Setting 5 V/DIV., 500 ms/DIV. Condition Procedure: Power switch off All doors closed All doors locked Lock or unlock switch of electrical key transmitter sub-assembly pressed

*a Before lock or unlock switch of electrical key transmitter sub-assembly pressed *b After lock or unlock switch of electrical key transmitter sub-assembly pressed

NG

REPLACE DOOR CONTROL RECEIVER

OK

14.	CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

(a) Measure the voltage according to the value(s) in the table below. Standard Voltage: Tester Connection Condition Specified Condition P11-1 (IG) - P11-12 (GND) Power switch on (IG) 10 to 16 V P11-10 (+5) - P11-12 (GND) Procedure: Power switch off Electrical key transmitter sub-assembly switch not pressed → pressed Below 1 V → 4.5 to 6.0 V → Below 1 V P11-6 (CSEL) - P11-12 (GND) Procedure: Power switch off All doors closed Below 1 V → Pulse generation

*a Component with harness connected (Door Control Receiver)

NG

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

OK

15.	REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

(a) Replace the certification ECU (smart key ECU assembly) and perform registration again.

NEXT

16.	CHECK WIRELESS DOOR LOCK CONTROL SYSTEM

(a) Check that the wireless door lock functions operate normally.

Click here

Result	Proceed to
Wireless door lock function operates normally	A
Wireless door lock function does not operate normally	B

A

END (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) WAS DEFECTIVE)

B

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

17.	INSPECT TRANSMITTER BATTERY

(a) Inspect the transmitter battery.

Click here

NOTICE:

Do not wrap the lead wire around a terminal, wedge it between terminals, or solder it. The terminal may be deformed or damaged, and the transmitter battery will not be able to be installed correctly.

OK

REPLACE ELECTRICAL KEY TRANSMITTER SUB-ASSEMBLY

NG

REPLACE TRANSMITTER BATTERY

18.	PERFORM REGISTRATION

(a) Perform registration of the B code.

HINT:

Refer to Registration (ECU CODE REGISTRATION).

Click here

NEXT

19.	CHECK ENTRY LOCK OPERATION

(a) After B code registration is complete, check that the entry lock and unlock functions operate.

Click here

Result	Proceed to
Entry function does not operate normally	A
Entry function operates normally	B

B

END (B CODE REGISTRATION FAILED)

A

20.	READ VALUE USING TECHSTREAM (B CODE)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

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

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

Body Electrical > Smart Access > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
B Code	B code registration status	Regd or No Regd	Regd: B code registered correctly No Regd: B code not registered correctly	-

Body Electrical > Smart Access > Data List

Tester Display
B Code

Result	Proceed to
"No Regd" is displayed on the Techstream	A
"Regd" is displayed on the Techstream	B

B

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

A

21.	READ VALUE USING TECHSTREAM (B CODE DIFFERENCE)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

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

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

Body Electrical > Smart Access > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
B Code Difference	B code mismatch	Yes or No	Yes: Communication malfunction No: Communication normal	-

Body Electrical > Smart Access > Data List

Tester Display
B Code Difference

Result	Proceed to
"No" is displayed on the Techstream	A
"Yes" is displayed on the Techstream	B

B

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

A

22.	CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

(a) Measure the voltage while checking the Data List on the Techstream.

(1) Connect the Techstream to the DLC3.

(2) Turn the power switch on (IG).

(3) Turn the Techstream on.

(4) Enter the following menus: Body Electrical / Power Source Control / Data List.

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

*a

Component with harness connected (Certification ECU (Smart Key ECU Assembly))

-

-

Body Electrical > Power Source Control > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
Power Supply Condition	Power supply state	All OFF, ACC ON, IG ON or ST ON	All OFF: Power switch off (ACC and IG) ACC ON: Power switch on (ACC) IG ON: Power switch on (IG) ST ON: Sending hybrid control system start request signal	-

Body Electrical > Power Source Control > Data List

Tester Display
Power Supply Condition

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
I51-3 (IG1D) - Body ground	Power switch off	Below 1 V
	Power switch on (ACC)	Below 1 V
	Power switch on (IG)	9 V or higher
I53-9 (ACCD) - Body ground	Power switch off	Below 1 V
	Power switch on (ACC)	9 V or higher
	Power switch on (IG)	9 V or higher

NG

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

OK

23.	READ VALUE USING TECHSTREAM (ACC SW, IG SW)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

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

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

Body Electrical > Main Body > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
ACC SW	Power switch status	ON or OFF	ON: Power switch on (ACC) OFF: Power switch off	"ON" is displayed even though the power switch is on (IG).
IG SW	Power switch status	ON or OFF	ON: Power switch on (IG) OFF: Power switch off	"OFF" is displayed even though the power switch is on (ACC).

Body Electrical > Main Body > Data List

Tester Display
ACC SW
IG SW

HINT:

If the certification ECU (smart key ECU assembly) misjudges for any reason that the power switch is on (IG) even though the power switch is off, the entry lock and unlock functions stop.

Result	Proceed to
The main body ECU (multiplex network body ECU) judges properly that the power source is off when the power switch is off	A
The main body ECU (multiplex network body ECU) does not judge properly that the power source is off when the power switch is off	B

B

TROUBLESHOOT MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

A

24.	CHECK ENTRY LOCK OPERATION

(a) Disconnect and reconnect the certification ECU (smart key ECU assembly) connector.

(b) Check that the entry lock and unlock functions operate.

Click here

Result	Proceed to
Entry function does not operate normally	A
Entry function operates normally	B

B

END (CONNECTOR WAS NOT CONNECTED SECURELY)

A

25.	REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

(a) Replace the certification ECU (smart key ECU assembly) with a new one and perform registration again.

NEXT

26.	CHECK WIRELESS DOOR LOCK CONTROL SYSTEM

(a) Check that the wireless door lock functions operate normally.

Click here

Result	Proceed to
Wireless door lock function operates normally	A
Wireless door lock function does not operate normally	B

A

END (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) WAS DEFECTIVE)

B

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

27.	CHECK WAVE ENVIRONMENT

(a) Bring the electrical key transmitter sub-assembly that was checked first near the door control receiver and select the failed channel (the channel in which the buzzer did not sound) to recheck key diagnostic mode.

Result	Proceed to
The wireless buzzer does not sound	A
The wireless buzzer sounds	B

B

AFFECTED BY WAVE INTERFERENCE

A

28.	CHECK ELECTRICAL KEY TRANSMITTER SUB-ASSEMBLY

(a) Check if there is another electrical key transmitter sub-assembly available that is already registered to the vehicle.

Result	Proceed to
Another registered electrical key transmitter sub-assembly is not available	A
Another registered electrical key transmitter sub-assembly is available	B

B

GO TO STEP 30

A

29.	ELECTRICAL KEY TRANSMITTER SUB-ASSEMBLY REGISTRATION (NEW ELECTRICAL KEY TRANSMITTER SUB-ASSEMBLY)

(a) Register a new electrical key transmitter sub-assembly.

Click here

NEXT

30.	CHECK WAVE ENVIRONMENT

(a) Bring another registered electrical key transmitter sub-assembly near the door control receiver and select the failed channel (the channel in which the buzzer did not sound) to recheck key diagnostic mode.

Result	Proceed to
The wireless buzzer does not sound	A
The wireless buzzer sounds	B

B

END (ELECTRICAL KEY TRANSMITTER SUB-ASSEMBLY WAS DEFECTIVE)

A

31.	CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - DOOR CONTROL RECEIVER)

(a) Disconnect the I52 certification ECU (smart key ECU assembly) connector.

(b) Disconnect the P11 door control receiver connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
I52-19 (CSEL) - P11-6 (CSEL)	Always	Below 1 Ω
I52-19 (CSEL) or P11-6 (CSEL) - Body ground	Always	10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

32.	CHECK ENTRY LOCK OPERATION

(a) Connect all connectors and check that the entry lock and unlock functions operate.

Click here

Result	Proceed to
Entry function does not operate normally	A
Entry function operates normally	B

B

END (CONNECTOR WAS NOT CONNECTED SECURELY)

A

33.	CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

(a) Measure the voltage according to the value(s) in the table below. Standard Voltage: Tester Connection Condition Specified Condition P11-6 (CSEL) - P11-12 (GND) Procedure: Power switch off All doors closed Below 1 V → Pulse generation

*a Component with harness connected (Door Control Receiver)

NG

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

OK

34.	CHECK DOOR CONTROL RECEIVER

(a) Enter key diagnostic mode and select the channel for which the wireless buzzer did not sound.

(b) Measure the voltage according to the value(s) in the table below. Standard Voltage: Tester Connection Condition Specified Condition P11-9 (DATA) - P11-12 (GND) Procedure: Power switch off All doors closed All doors locked Lock or unlock switch of electrical key transmitter sub-assembly pressed Below 1 V → Pulse generation (See waveform 1) HINT: Inspection should be performed while the electrical key antenna check in key diagnostic mode is being performed on the failed channel (the channel in which the buzzer did not sound).

*a Component with harness connected (Door Control Receiver)

(c) Using an oscilloscope, check waveform 1. NOTICE: The oscilloscope waveform shown in the illustration is an example for reference only. Noise, chattering, etc. are not shown. Waveform 1 (Reference) Item Content Tester Connection P11-9 (DATA) - P11-12 (GND) Tool Setting 5 V/DIV., 500 ms/DIV. Condition Procedure: Power switch off All doors closed All doors locked Lock or unlock switch of electrical key transmitter sub-assembly pressed

*a Before lock or unlock switch of electrical key transmitter sub-assembly pressed *b After lock or unlock switch of electrical key transmitter sub-assembly pressed

NG

REPLACE DOOR CONTROL RECEIVER

OK

35.	REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

(a) Replace the certification ECU (smart key ECU assembly) and perform registration again.

NEXT

36.	CHECK WIRELESS DOOR LOCK CONTROL SYSTEM

(a) Check that the wireless door lock functions operate normally.

Click here

Result	Proceed to
Wireless door lock function operates normally	A
Wireless door lock function does not operate normally	B

A

END (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) WAS DEFECTIVE)

B

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

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