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Power Mirror Ecu Circuit Test

  1. Remove power mirror ECU. Disconnect electrical connectors from power mirror ECU. Check for continuity between specified terminals. See POWER MIRROR ECU CONTINUITY TEST  table. See Fig 1. If there is no continuity, repair wiring or component as necessary.
  2. If there is continuity, reconnect electrical connectors. Check voltage between ground and specified terminals. See POWER MIRROR ECU VOLTAGE TEST  table. If voltage is as specified, circuits are okay; replace power mirror ECU. If voltage is not as specified, check wiring and components as necessary. If wiring and components are okay, replace power mirror ECU.
POWER MIRROR ECU CONTINUITY TEST

Condition Terminals
Always (1) ;A1 & A2; A1 & A3; A8 & A10; A9 & A10; A11 & Ground; A12 & A13
Select Switch LEFT
UP B3 & B6
DOWN B1 & B6
LEFT B3 & B5
RIGHT B1 & B5
Select Switch RIGHT
UP B2 & B3
DOWN B1 & B2
LEFT B3 & B4
RIGHT B1 & B4
(1) There should be continuity between terminal A16 of power mirror ECU and terminal No. 9 of tilt and telescoping ECU connector "B". See Fig 1 and Fig 2.
POWER MIRROR ECU VOLTAGE TEST

Terminal Condition Volts
A4 Always Battery
A7 Ignition ACC Battery
A7 Ignition OFF Zero
A1 Right Mirror, LEFT Battery
A2 Right Mirror, UP Battery
A3 Right Mirror, RIGHT Or DOWN Battery
A5 Right Mirror, LEFT (1) 0.0-0.9
A5 Right Mirror, RIGHT (1) 2.8-5.0
A6 Right Mirror, DOWN (1) 2.8-5.0
A6 Right Mirror, UP (1) 0.0-0.9
A8 Left Mirror, RIGHT Battery
A9 Left Mirror, UP Battery
A10 Left Mirror, DOWN Or LEFT Battery
A13 Either Mirror, Except OFF About 5.0
A14 Left Mirror, LEFT (1) 2.8-5.0
A14 Left Mirror, RIGHT (1) 0.0-0.9
A15 Left Mirror, DOWN (1) 2.8-5.0
A15 Left Mirror, UP (1) 0.0-0.9
B2 Always About 5.0
B4 Always About 5.0
B5 Always About 5.0
B6 Always About 5.0
(1) As mirror moves, voltage should gradually change.
Fig 1: Testing Power Mirror ECU Circuits (LS400)
G92C01029Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Fig 2: Terminal Of Tilt & Telescoping ECU Connector "B" ID (LS400)
G92E01030Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002