DTC B1231: Jam Protection Limit Switch Circuit on Driver Door; DTC B1232: Jam Protection Pulse Switch Circuit on Driver Door: Procedure

1. Lower the driver door power window from the fully closed position to the fully open position. Check if the DTC is erased.
   RESULT
   
   

   Result	Proceed to
   DTC is not erased	A
   DTC is erased	B

   HINT: 

   If the DTC is erased, it is possible that the multiplex network door ECU front LH incorrectly detected this DTC previously.

B → END 

A: Go to next step 

1. Reset the power window regulator motor. Refer to INITIALIZATION .
2. Check if the power window AUTO UP / DOWN function operates normally.

   OK

   AUTO UP / DOWN function operates normally.

OK → END 

NG: Go to next step 

1. Check the Data List for proper functioning of the limit switch.
   MULTIPLEX NETWORK DOOR ECU FRONT LH
   
   

   Item	Measurement Item / Display (Range)	Normal Condition	Diagnostic Note
   LIMIT SW	Jam protection limit switch / ON or OFF	ON: Jam protection limit switch operates OFF: Jam protection limit switch does not operate	-

   OK

   ON (jam protection limit switch operates) appears on screen.

OK → REPLACE MULTIPLEX NETWORK DOOR ECU FRONT LH 

NG: Go to next step 

Fig 1: Identifying D23 ECU And P15 Motor Connectors

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the D23 ECU connector.
2. Disconnect the P15 motor connector.
3. Measure the resistance of the wire harness side connectors.

   Standard Resistance

   Tester Connection	Specified Condition
   D23-10 (LMT) - P15-4 (LMT)	Below 1 Ω
   D23-21 (PLS) - P15-3 (PLS)	Below 1 Ω
   D23-11 (SGND) - P15-5 (E)	Below 1 Ω
   D23-10 (LMT) or P15-4 (LMT) - Body ground	10 kΩ or higher
   D23-21 (PLS) or P15-3 (PLS) - Body ground	10 kΩ or higher
   D23-11 (SGND) or P15-5 (E) - Body ground	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS AND CONNECTOR 

OK: Go to next step 

1. Temporarily replace the multiplex network door ECU front LH with a new or normally functioning one.
2. Check that a DTC is not output.

   OK

   DTC is not output.

NG → REPLACE FRONT POWER WINDOW REGULATOR MOTOR ASSEMBLY LH 

OK → END (ECU DEFECTIVE)