SMART ENTRY AND START SYSTEM (for Entry Function) Back Door Entry Lock and Unlock Functions do not Operate

DESCRIPTION

If the entry lock and unlock functions do not operate for the back door only, the request code may not be being transmitted from the back door or the license plate light assembly (trigger switch) may be malfunctioning. If the entry functions for other doors operate properly, communication between the electrical key transmitter sub-assembly and certification ECU (smart key ECU assembly) is normal. In this case, there may be a problem with request code transmission (communication between the certification ECU [smart key ECU assembly]) license plate light assembly (trigger switch) or electrical key antenna), or there may be wave interference.

WIRING DIAGRAM

INSPECTION PROCEDURE

Note

The smart entry and start system (for Entry Function) uses a multiplex communication system (LIN communication system) and the CAN communication system. Inspect the communication function by following How to Proceed with Troubleshooting Click here. Troubleshoot the smart entry and start system (for Entry Function) after confirming that the communication systems are functioning properly.
and turn a courtesy light switch on and off at intervals of 1.5 seconds or less until communication between the GTS and the vehicle begins. Then select the Model Code "KEY REGIST" under manual mode and enter the following menus: Body Electrical / Entry&Start(CAN).

While using the GTS, periodically turn a courtesy light switch on and off at intervals of 1.5 seconds or less to maintain communication between the GTS and the vehicle.
Check that there are no electrical key transmitter sub-assemblies in the vehicle.
Before replacing the certification ECU (smart key ECU assembly), refer to the smart entry and start system (for Entry Function) precaution Click here.
After repair, confirm that no DTCs are output by performing the "DTC Output Confirmation Operation".

PROCEDURE

CHECK POWER DOOR LOCK OPERATION
1. When the door control switch on the power window regulator master switch assembly is operated, check that the doors unlock and lock according to the switch operation.
  
  OK
  
  Door locks operate normally.
NG
GO TO POWER DOOR LOCK CONTROL SYSTEM Click here

OK

OK
Door locks operate normally.

CHECK FOR DTC

Check for DTCs Click here.

Result
Result	Proceed to
DTC B27A8 is not output.	A
DTC B27A8 is output.	B

Go to DTC B27A8 Click here

CHECK WAVE ENVIRONMENT

Text in Illustration
*a	Approximately 0.3 m (0.984 ft.)

Bring the electrical key transmitter sub-assembly approximately 0.3 m (0.984 ft.) from the license plate light assembly and perform an entry function check Click here.

Note

If the electrical key transmitter sub-assembly is brought within 0.2 m (0.656 ft.) of license plate light assembly, communication may not be possible.

Tech Tips

If the inspection result is that the problem only occurs in certain locations or at certain times of day, the possibility of wave interference is high. Also, added vehicle components may cause wave interference. If installed, remove them and perform the operation check.

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

AFFECTED BY WAVE INTERFERENCE

READ VALUE USING GTS (Tr/B - DOOR UNLOCK SWITCH)

Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Enter the following menus: Body Electrical / Entry&Start / Data List.

According to the display on the GTS, read the Data List.

Entry&Smart
Tester Display	Measurement Item / Range	Normal Condition	Diagnostic Note
Tr/B-Door Unlock SW	Back door trigger switch / ON or OFF	ON: Back door trigger switch pushed OFF: Back door trigger switch not pushed	Displays whether the back door opening switch assembly is on or off. Use this Data List item to help determine if there is a switch malfunction when the back compartment door open function does not operate.

OK
On the GTS screen, the display changes between ON and OFF as shown in the table above.

CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU [SMART KEY ECU ASSEMBLY] - LICENSE PLATE LIGHT ASSEMBLY AND BODY GROUND) Click here

CHECK KEY DIAGNOSTIC MODE
1. Text in Illustration
  
  *a 0.7 to 1 m (2.30 to 3.28 ft.)
  
  Check the following antennas in key diagnostic mode.
2. Select either channel 1 or channel 2 and perform the key diagnostic mode inspection for each channel.
  
  Tech Tips
  
  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.
  1. Check the electrical key antenna (back 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 license plate light assembly, check that the wireless door lock buzzer sounds.
    
    OK
    
    Wireless door lock buzzer sounds.
NG
CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU [SMART KEY ECU ASSEMBLY] - ELECTRICAL KEY ANTENNA) Click here

OK

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

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

OK
Wireless door lock buzzer sounds.

CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU [SMART KEY ECU ASSEMBLY] - ELECTRICAL KEY ANTENNA)

Disconnect the B76 certification ECU (smart key ECU assembly) connector.
Disconnect the S1 electrical key antenna (back door) connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
B76-8 (CLG8) - S1-2 (ANTE8)	Always	Below 1 Ω
B76-24 (CG8B) - S1-1 (CLGB)	Always	Below 1 Ω
B76-8 (CLG8) or S1-2 (ANTE8) - Body ground	Always	10 kΩ or higher
B76-24 (CG8B) or S1-1 (CLGB) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

Connect the B76 certification ECU (smart key ECU assembly) connector.
Connect the S1 electrical key antenna (back door) connector.

Using an oscilloscope, check the waveform.

Text in Illustration
*a	Component with harness connected (Certification ECU [Smart Key ECU Assembly])	*b	Waveform 1
*c	Trigger switch ON	-	-

Tester Connection

Switch Condition

Tool Setting

Specified Condition

B76-8 (CLG8) - B76-24 (CG8B)

Procedure:

Engine switch off
All doors closed

Not pulse generation

Procedure:

Engine switch off
All doors closed
Press the trigger switch on the licence plate light assembly

2 V/DIV., 500 ms/DIV.

Pulse generation (See waveform 1)

CHECK ENTRY DOOR LOCK OPERATION Click here

REPLACE ELECTRICAL KEY ANTENNA (BACK DOOR) Click here

CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU [SMART KEY ECU ASSEMBLY] - LICENSE PLATE LIGHT ASSEMBLY AND BODY GROUND)

Disconnect the B75 certification ECU (smart key ECU assembly) connector.
Disconnect the a10 license plate light assembly (trigger switch) connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
B75-14 (TSW5) - a10-1	Always	Below 1 Ω
a10-2 - Body ground	Always	Below 1 Ω
B75-14 (TSW5) or a10-1 - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

INSPECT LICENSE PLATE LIGHT ASSEMBLY (TRIGGER SWITCH)
1. Remove the license plate light assembly Click here.
2. Inspect the license plate light assembly Click here.
NG
REPLACE LICENSE PLATE LIGHT ASSEMBLY Click here

OK
CHECK ENTRY DOOR LOCK OPERATION
1. Check the operation of the entry lock/unlock function.
  
  Tech Tips
  
  Disconnect and reconnect the connectors of certification ECU (smart key ECU assembly) and license plate light assembly before performing the inspection.
  
  OK
  
  Entry lock/unlock operate normally.
NG
REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

OK

END (CONNECT CONNECTORS PROPERLY)