DTC B2251: Back Door Closer Switch Malfunction: Procedure

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

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Courtesy SW	Back door courtesy light switch signal / ON or OFF	ON: Back door is open OFF: Back door is closed	-

   OK

   The display is as specified in the normal condition.

NG → See step   2 

OK → See step   5 

Fig 1: Identifying Back Door Lock Component & Connector Terminal Identification

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Remove the back door lock, refer to REMOVAL
2. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Back door courtesy light switch 

   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   4 

OK: Go to next step 

1. Disconnect the T4 door lock connector.
   Fig 2: Identifying T4 Door Lock & O15 ECU Connector Terminal Identification

   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
   T4-3 (BDCY) - O15-20 (FUL)	Always	Below 1 Ω
   T4-4 (GND) - Body ground	Always	Below 1 Ω
   T4-3 (BDCY) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   5