Test D: Power Seat Control Ecu

Check ECU ground circuit for high resistance, poor connections or defects. If high resistance or defects are found, repair as necessary and recheck circuit to verify repair. If high resistance or defects were not found, replace ECU with a normal functioning one and check if symptoms reappear.
Check ECU terminal circuits. See Figure,Figure, Fig 1 and Fig 2 . If circuits are not as indicated, replace ECU with a normal functioning one and check if symptoms reappear.

Fig 1: Checking Seat Control ECU Circuits (Avalon - 1 Of 2)
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Fig 2: Checking Seat Control ECU Circuits (Avalon - 2 Of 2)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002