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 POWER DOOR LOCK OPERATION
NG: GO TO POWER DOOR LOCK CONTROL SYSTEM (See INSPECTION )
OK: Go to next step.
- CHECK DTC
Data list (for MANUAL UP/DOWN switch)
- Using the hand-held tester, check that DTC B1221 is output when the switch is operated.
HINT: Using DTC "B1221" which is a code when any of the master switch is constantly turned on, the MANUAL UP/DOWN switch operation can be monitored. If there is an output of DTC "B1221" when the switch is operated, the switch circuit can be considered normal.
Standard [Driver side J/B (body ECU) (Switch condition)]:
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NG: REPLACE POWER WINDOW REGULATOR MASTER SWITCH ASSY
OK: Go to next step.
- CONFIRM REMOTE CONTROL POWER WINDOW BY MASTER SWITCH OPERATION
HINT:
- When the rear door does not operate by master switch, proceed to "A".
- When the passenger's door does not operate by master switch, proceed to "B".
B: REPAIR OR REPLACE WIRE HARNESS AND CONNECTOR MPX2 (D17-8) <=> MPX2 (F13-8) WIRE HARNESS
A: Go to next step.
- CHECK CONTINUITY OF COMMUNICATION LINE
- Disconnect the B5 and B6 connectors of the driver side J/B.
- Disconnect the R15 power window regulator switch assy rear (LH side) connector.
- Disconnect the R16 power window regulator switch assy rear (RH side) connector.
- Check the continuity of each terminal of the disconnected connectors.
Standard (Rear door LH):
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Standard (Rear door RH):
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
HINT:
- When the rear door LH does not inspect the continuity, proceed to "NG-A".
- When the rear door RH does not inspect the continuity, proceed to "NG-B".
NG-A: REPAIR OR REPLACE WIRE HARNESS AND CONNECTOR MPX4 (B6-5) <=> MPX1 (R15-8) WIRE HARNESS
NG-B: REPAIR OR REPLACE WIRE HARNESS AND CONNECTOR MPX5 (B5-1) <=> MPX1 (R16-8) WIRE HARNESS
OK: REPLACE DRIVER SIDE JUNCTION BLOCK ASSY
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.