Seat

Lock Switch Circuit

5steps
~30min
2/5difficulty
Done 0 of 5

DESCRIPTION

Each of the left and right seats has lock switches that detect the lock condition of the seat legs to the floor when the seat is in the original or folded-down state. If any of the lock switches detect an unlock condition, the 3rd SEAT indicator on the combination meter will come on and the folding-down, return, and reclining operations will be disabled.

WIRING DIAGRAM

WIRING DIAGRAM

INSPECTION PROCEDURE

1 INSPECT FOLD SEAT CONTROL ECU

INSPECT FOLD SEAT CONTROL ECU
  1. Remove the fold seat control ECU with connector still connected.
  2. Measure the voltage according to the value(s) in the table below.

Standard voltage LH side

Standard voltage

RH side

Standard voltage

2 CHECK HARNESS AND CONNECTOR (FOLD SEAT CONTROL ECU - LOCK SWITCH)

CHECK HARNESS AND CONNECTOR
  1. Disconnect the connectors from the fold seat control ECU.
  2. Disconnect the connector from the lock switch.
  3. Measure the resistance according to the value(s) in the table below.

Standard resistance LH side

Standard resistance

RH side

Standard resistance

3 CHECK HARNESS AND CONNECTOR (LOCK SWITCH - BODY GROUND)

CHECK HARNESS AND CONNECTOR
  1. Measure the resistance according to the value(s) in the table below.

Standard resistance LH side

Standard resistance

RH side

Standard resistance

4 REPLACE LOCK SWITCH

HINT: Since the lock switch cannot be inspected while it is removed from the vehicle, replace the lock switch with a normal one and check that the condition returns to normal.

OK: Same problem does not occur.

REPLACE FOLD SEAT CONTROL ECU

Test yourself

A quick Toyota Sienna quiz: every answer comes with an explanation and a link to the manual page.