Back Door cannot be Opened: Procedure

1. Check the Data List to determine if the back door lock function properly.
   BACK DOOR (POWER BACK DOOR ECU)
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Door Lock Status	Back door lock condition signal / LOCK or UNLOCK	LOCK: Back door is locked UNLOCK: Back door is unlocked	-

   OK

   The back door functions as specified in the normal condition.

NG → See step   7 

OK: Go to next step 

1. Check the Data List to determine if the back door handle switch function properly.
   MAIN BODY (MAIN 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 is pushed OFF: Back door opener switch is not pushed	-

   OK

   The back door opener switch functions as specified in the normal condition.

NG → See step   5 

OK: Go to next step 

Fig 1: Inspecting Back Door Lock

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Remove the back door lock, refer to REMOVAL .
2. Apply battery voltage and check operation of the door lock motor.

   OK

   Measurement Condition	Specified Condition
   Battery positive (+) → Terminal 1 (DC+) Battery negative (-) → Terminal 2 (DC-)	Latch turns to full-latch position
   Battery positive (+) → Terminal 2 (DC-) Battery negative (-) → Terminal 1 (DC+)	Latch turns to open-latch position

3. Measure the resistance of the switch.

   Standard resistance

   Full-latch switch 

   Sector switch 

   Back door courtesy light switch 

   Tester Connection	Door Lock Latch Position	Specified Condition
   5 (HAF) - 4 (GND)	Over-latch	Below 1 Ω
   5 (HAF) - 4 (GND)	Open-latch	10 kΩ or higher
   5 (HAF) - 4 (GND)	Full-latch	10 kΩ or higher
   5 (HAF) - 4 (GND)	Half-latch	10 kΩ or higher

   Tester Connection	Door Lock Latch Position	Specified Condition
   6 (POS) - 4 (GND)	Open-latch	Below 1 Ω
   6 (POS) - 4 (GND)	Over-latch	10 kΩ or higher
   6 (POS) - 4 (GND)	Full-latch	10 kΩ or higher
   6 (POS) - 4 (GND)	Half-latch	10 kΩ or higher

   Tester Connection	Door Lock Latch Position	Specified Condition
   3 (BDCY) - 4 (GND)	Open-latch	Below 1 Ω
   3 (BDCY) - 4 (GND)	Half-latch	Below 1 Ω
   3 (BDCY) - 4 (GND)	Full-latch	10 kΩ or higher
   3 (BDCY) - 4 (GND)	Over-latch	10 kΩ or higher

NG → See step   11 

OK: Go to next step 

1. Disconnect the T4 back door lock connector.
   Fig 2: Identifying Back Door Lock And Power Back Door ECU Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the O15 ECU connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   T4-1 (DC+) - O15-2 (DC+)	Always	Below 1 Ω
   T4-2 (DC-) - O15-1 (DC-)	Always	Below 1 Ω
   T4-5 (HAF) - O15-22 (HAF)	Always	Below 1 Ω
   T4-6 (POS) - O15-24 (POS)	Always	Below 1 Ω
   T4-3 (BDCY) - O15-20 (FUL)	Always	Below 1 Ω
   T4-4 (GND) - Body ground	Always	Below 1 Ω
   T4-1 (DC+) - Body ground	Always	10 kΩ or higher
   T4-2 (DC-) - Body ground	Always	10 kΩ or higher
   T4-5 (HAF) - Body ground	Always	10 kΩ or higher
   T4-6 (POS) - Body ground	Always	10 kΩ or higher
   T4-3 (BDCY) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   9 

1. Remove the back door opener switch, refer to REMOVAL .
   Fig 3: Identifying Back Door Opener Switch

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Switch Position	Specified Condition
   2 - 3	Back door opener switch not pushed (OFF)	10 kΩ or higher
   2 - 3	Back door opener switch pushed (ON)	Below 1 Ω

NG → See step   10 

OK: Go to next step 

1. Disconnect the h1 switch connector.
   Fig 4: Identifying Back Door Opener Switch And Main Body ECU Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the D8 ECU connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   h1-3 - D8-26 (BDSU)	Always	Below 1 Ω
   h1-2 - Body ground	Always	Below 1 Ω
   h1-3 - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK) 

1. Replace the power back door drive unit (power back door ECU), refer to REMOVAL .

NEXT: Go to next step 

1. Check that the back door closer operates normally.

   OK

   It operates normally.

NG → REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK) 

OK → END (REPLACE BACK DOOR MOTOR UNIT (POWER BACK DOOR ECU) DEFECTIVE)