Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Inspection Procedure
- CHECK WIRELESS DOOR LOCK CONTROL FUNCTIONS (See
ON-VEHICLE INSPECTION )
- NG: Go to step 2
- OK: NORMAL
- REPLACE TRANSMITTER BATTERY (See
INSPECTION )
- After replacing the transmitter battery with a new or functioning one, check that the doors can be locked and unlocked by using the transmitter LOCK/UNLOCK switch.
- NG: Go to step 3
- OK: END
- CHECK WIRELESS DOOR LOCK FUNCTIONS (STANDARD OPERATION)
- Check standard LOCK/UNLOCK switch operation.NOTE: Standardized test procedure: press the transmitter switch for 1 second, directing the beam to driver side door outside handle from a distance of 1 m (3.28 ft). The transmitter should be pointed directly at the door handle, i.e. at 90° angle to the vehicle body.
- NG: Go to step 4
- OK: REPLACE DOOR CONTROL TRANSMITTER
- Check standard LOCK/UNLOCK switch operation.
- CHECK WIRELESS DOOR LOCK BUZZER
- Check that the wireless door lock buzzer sounds (see
ON-VEHICLE INSPECTION ).
OK: Wireless door lock buzzer sounds.
- NG: Go to step 18
- OK: Go to next step
- Check that the wireless door lock buzzer sounds (see
ON-VEHICLE INSPECTION ).
- SWITCH TO SELF-DIAGNOSTIC MODE
- Switch to self-diagnostic mode on the hand-held tester.
- Connect the hand-held tester to the DLC3.
- Turn the ignition switch ON and push the hand-held tester main switch ON.
- Please refer to the hand-held tester operator's manual for further details.
- Switch to self-diagnostic mode by operating the ignition key cylinder.
- Put the vehicle under the vehicle's initial condition (see ON-VEHICLE INSPECTION ), insert the key into the ignition key cylinder and remove it.
- Within 5 seconds of removing the key (step 1), insert the key into the ignition key cylinder (ignition key OFF). Then turn the ignition switch to ON and return it to OFF.
- Within 30 seconds returning the ignition switch OFF again (step 2), perform the following 9 times: Turn the ignition switch to ON and return it to OFF.
NOTE: If the change to self-diagnostic mode has failed, the system will return to normal mode.HINT:
- Turning the ignition switch ON after step b-(3) has been completed will end self-diagnostic mode.
- Do not lock or unlock doors during self-diagnostic mode.
- Check that the system has switched to self-diagnostic mode by checking the wireless door lock buzzer sound. Compare the buzzer sound to the illustration on the left.
OK:
The buzzer sound should be the same as that shown in Fig 1 .
- NG: Go to step 10
- OK: Go to next step
- Switch to self-diagnostic mode on the hand-held tester.
- CHECK BY SELF-DIAGNOSTIC MODE
- Inspect the diagnosis outputs when the door control transmitter switch is held down. The diagnosis outputs can be checked by listening to the wireless door lock buzzer.
Result:
BUZZER OUTPUT RESULTResult Proceed to Normal waves (buzzer sound patterns) for LOCK, UNLOCK, TRUNK OPEN or PANIC switches are output. A Unmatching recognition code is output and buzzer is ON. B No diagnosis outputs are present and buzzer is OFF. C
- B: REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSY (MULTIPLEX NETWORK BODY ECU)
- C: Go to step 8
- A: Go to next step
- Inspect the diagnosis outputs when the door control transmitter switch is held down. The diagnosis outputs can be checked by listening to the wireless door lock buzzer.
- REGISTER RECOGNITION CODE
- Check that the system can switch to rewrite mode or add mode and a recognition code can be registered.
OK: Recognition code can be registered.
- NG: Go to step 9
- OK: NORMAL
- Check that the system can switch to rewrite mode or add mode and a recognition code can be registered.
- CHECK RESPONSE OF DOOR CONTROL RECEIVER
- Prepare a new or functioning door control transmitter switch from the same vehicle model. Press and hold a switch on the transmitter and check that an unmatching recognition code is output.
OK: Unmatching recognition code is output.
- NG: Go to step 14
- OK: REPLACE DOOR CONTROL TRANSMITTER
- Prepare a new or functioning door control transmitter switch from the same vehicle model. Press and hold a switch on the transmitter and check that an unmatching recognition code is output.
- REPLACE DOOR CONTROL RECEIVER
- After replacing the door control receiver, check that the doors can be locked and unlocked by using the transmitter LOCK/UNLOCK switch.
OK: Doors can be locked and unlocked with transmitter.
- NG: REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSY (MULTIPLEX NETWORK BODY ECU)
- OK: END
- After replacing the door control receiver, check that the doors can be locked and unlocked by using the transmitter LOCK/UNLOCK switch.
- CONFIRM INPUT METHOD OF SELF-DIAGNOSTIC MODE
Result:
SELF DIAGNOSTIC RESULTResult Proceed to The method for changing the system to self-diagnostic mode works. A The method for changing the system to self-diagnostic mode does not work. B - B: Go to step 5
- A: Go to next step
- INSPECT UNLOCK WARNING SWITCH ASSY
- Remove the switch.
- Measure the resistance of the switch.
Standard:
CONNECTOR SPECIFIED CONDITIONTester Connection Switch Condition Specified Condition 1 - 2 Not pushed 10 kΩ or higher 1 - 2 Pushed Below 1 Ω
- NG: REPLACE UNLOCK WARNING SWITCH ASSY
- OK: Go to next step
- CHECK WIRE HARNESS (UNLOCK WARNING SWITCH ASSY - MULTIPLEX NETWORK BODY ECU AND BODY GROUND)
- Disconnect the U1 switch connector.
- Disconnect the B6 ECU connector.
- Measure the resistance of the wire harness side connectors.
Standard:
CONNECTOR SPECIFIED CONDITIONTester Connection Specified Condition U1-2 - B6-21 (KSW) Below 1 Ω U1-1 - Body ground Below 1 Ω
- NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
- OK: Go to next step
- CHECK WIRE HARNESS (DOOR CONTROL RECEIVER - BATTERY AND BODY GROUND)
- Disconnect the D4 receiver connector.
- Measure the voltage and resistance of the wire harness side connector.
Standard:
CONNECTOR SPECIFIED CONDITIONTester Connection Specified Condition D4-5 (+B) - Body ground 10 to 14 V D4-1 (E) - Body ground Below 1 Ω
- NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
- OK: Go to next step
- CHECK DOOR CONTROL RECEIVER (OUTPUT)
- Measure the voltage of the connector.
Standard:
- NG: Go to step 9
- OK: Go to next step
- Measure the voltage of the connector.
- CHECK WIRE HARNESS (DOOR CONTROL RECEIVER - MULTIPLEX NETWORK BODY ECU)
- Disconnect the D4 receiver connector.
- Disconnect the B8 ECU connector.
- Measure the resistance of the wire harness side connectors.
Standard:
CONNECTOR SPECIFIED CONDITIONTester Connection Specified Condition D4-2 (RDA) - B8-12 (RDA) Below 1 Ω D4-2 (RDA) - Body ground 10 kΩ or higher B8-12 (RDA) - Body ground 10 kΩ or higher
- NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
- OK: Go to next step
- CHECK WIRELESS DOOR LOCK CONTROL FUNCTIONS
Result:
WIRELESS DOOR LOCK CONTROL FUNCTIONS RESULTResult Proceed to Wireless door lock functions but hazard warning lamp answer-back does not occur. A Wireless door lock functions but wireless door lock buzzer answer-back does not occur. B Wireless door lock functions but hazard warning lamp answer-back and wireless door lock buzzer answer-back do not occur. C - B: Go to step 18
- C: REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSY (MULTIPLEX NETWORK BODY ECU)
- A: Go to next step
- CHECK HAZARD WARNING LAMPS
- Check that the hazard warning lamps blink when the hazard warning signal switch is pressed.
OK: Hazard warning lamps blink.
- NG: Go to LIGHTING SYSTEM (See LIGHTING SYSTEM - DIAGNOSTICS )
- OK: REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSY (MULTIPLEX NETWORK BODY ECU)
- Check that the hazard warning lamps blink when the hazard warning signal switch is pressed.
- INSPECT WIRELESS DOOR LOCK BUZZER
- Measure the resistance between terminals 1 and 2 of the buzzer.
Standard: Approximately 1 kΩ
NOTE:- The buzzer circuit is built into the multiplex network body ECU, not into the buzzer itself.
- When battery voltage is directly applied to the buzzer, the buzzer does not sound.
- NG: REPLACE WIRELESS DOOR LOCK BUZZER
- OK: Go to next step
- Measure the resistance between terminals 1 and 2 of the buzzer.
- CHECK WIRE HARNESS (WIRELESS DOOR LOCK BUZZER - MULTIPLEX NETWORK BODY ECU AND BODY GROUND)
- Disconnect the K1 buzzer connector.
- Disconnect the B9 ECU connector.
- Measure the resistance of the wire harness side connectors.
Standard:
CONNECTOR SPECIFIED CONDITIONTester Connection Specified Condition K1-1 - B9-2 (BZR) Below 1 Ω K1-2 - Body ground Below 1 Ω
- NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
- OK: REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSY (MULTIPLEX NETWORK BODY ECU)
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.