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.
Only Back Door cannot be Opened: Procedure
- SYSTEM CHECK
- Check the vehicle specification.
Result
Result Proceed to w/o Entry System Back Door Open Function A w/ Entry System Back Door Open Function B
B → See step 6
A: Go to next step
- Check the vehicle specification.
- CHECK POWER DOOR LOCK OPERATION (BASIC FUNCTION)
- Check the power door lock basic function. Refer to OPERATION CHECK .
OK
The power door lock basic functions operate normally.
NG → See step 14
OK: Go to next step
- Check the power door lock basic function. Refer to OPERATION CHECK .
- READ VALUE USING TECHSTREAM (DOOR LOCK STATUS)
- Connect the Techstream to the DLC3.
- Turn the power switch on (IG).
- Turn the Techstream on.
- Enter the following menus: Body Electrical / Main Body / Data List.
- Read the Data List according to the display on the Techstream.MAIN BODY (MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU))
Tester Display Measurement Item/Range Normal Condition Diagnostic Note Back Door Open Back door lock/Permit or Prohibt Permit: Back door unlocked
Prohibt: Back door locked- OK
The Techstream indicates Permit or Prohibit according to the door lock operation shown in the table.
NG → See step 15
OK: Go to next step
- PERFORM ACTIVE TEST USING TECHSTREAM
- Connect the Techstream to the DLC3.
- Turn the power switch on (IG).
- Turn the Techstream on.
- Enter the following menus: Body Electrical / Main Body / Active Test.
- Perform the Active Test according to the display on the Techstream.MAIN BODY (MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU))
Tester Display Test Part Control Range Diagnostic Note Trunk and Back-Door Open Operate back door lock motor ON or OFF - OK
The back door lock assembly unlatches when ON is selected.
NG → See step 6
OK: Go to next step
- READ VALUE USING TECHSTREAM
- Connect the Techstream to the DLC3.
- Turn the power switch on (IG).
- Turn the Techstream on.
- Enter the following menus: Body Electrical / Main Body / Data List.
- Read the Data List according to the display on the Techstream.MAIN BODY (MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU))
Tester Display Measurement Item/Range Normal Condition Diagnostic Note Back Door Open Handle SW Back door opener switch signal/ON or OFF ON: Back door opener switch pushed
OFF: Back door opener switch not pushed- OK
The Techstream indicates ON or OFF according to the switch operation shown in the table.
NG → See step 10
OK → See step 15
- INSPECT BACK DOOR LOCK ASSEMBLY
- Remove the back door lock assembly. Refer to REMOVAL .
- Check the operation of the door lock motor.
- Check the operation of the door courtesy switch.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Switch Condition Specified Condition 2 (+) - 1 (E) Locked 10 kΩ or higher 2 (+) - 1 (E) Unlocked Below 1 Ω TEXT IN ILLUSTRATION*a Component without harness connected
(Back Door Lock Assembly)*b Lock *c Unlock
- Measure the resistance according to the value(s) in the table below.
NG → See step 12
OK: Go to next step
- CHECK HARNESS AND CONNECTOR (BACK DOOR LOCK ASSEMBLY - MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU))
- Disconnect the main body ECU (multiplex network body ECU) connector.
- Disconnect the instrument panel junction block assembly connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition R18-4 (ACT+) - 2D-9 Always Below 1 Ω R18-4 (ACT+) - Body ground Always 10 kΩ or higher R18-2 (+) - L7-19 (BCTY) Always Below 1 Ω R18-2 (+) - Body ground Always 10 kΩ or higher R18-3 (ACT-) - Body ground Always Below 1 Ω R18-1 (E) - Body ground Always Below 1 Ω
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: Go to next step
- REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY
- Replace the instrument panel junction block assembly. Refer to REMOVAL .
NEXT: Go to next step
- CHECK BACK DOOR OPEN OPERATION
- Check that the back door can be opened.
OK
The back door can be opened normally.
NG → See step 15
OK → END (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY WAS DEFECTIVE)
- Check that the back door can be opened.
- INSPECT BACK DOOR OPENER SWITCH ASSEMBLY
- Remove the back door opener switch assembly. Refer to REMOVAL .
- Check the operation of the opener switch.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Switch Condition Specified Condition 2 (E) - 3 (UL) Back door opener switch not pushed 10 kΩ or higher 2 (E) - 3 (UL) Back door opener switch pushed Below 1 Ω TEXT IN ILLUSTRATION*a Component without harness connected
(Back Door Opener Switch Assembly)
NG → See step 13
OK: Go to next step
- CHECK HARNESS AND CONNECTOR (BACK DOOR OPENER SWITCH ASSEMBLY - MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU))
- Disconnect the main body ECU (multiplex network body ECU) connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition V4-3 (UL) - L7-23 (BDSU) Always Below 1 Ω V4-3 (UL) - Body ground Always 10 kΩ or higher V4-2 (E) - Body ground Always Below 1 Ω
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK → See step 15
- REPLACE BACK DOOR LOCK ASSEMBLY. Refer to REMOVAL
- REPLACE BACK DOOR OPENER SWITCH ASSEMBLY. Refer to REMOVAL
- GO TO PROBLEM SYMPTOMS TABLE. Refer to PROBLEM SYMPTOMS TABLE
- REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to REMOVAL
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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.
