LS - 1st and 2nd Gen (1990-2000) Discussion topics related to the 1990 - 2000 Lexus LS400

1990 LS400, power mirrors not working

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Old 10-14-07, 08:07 PM
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ttyR2
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Default 1990 LS400, power mirrors not working

Neither of the power mirrors work in the car. I downloaded the repair manual from TIS (definitely worth the $10, thanks LexLS!) and went through the troubleshooting procedures for the mirror system. It would appear that the power mirror ECU is defective. I checked connectivity for the switch assembly (all switch functions check out) and power to the ECU. When triggering various functions using the switch, no output voltage is recorded from the ECU. If that's the case, it can't be an issue with the power mirror motors or anything else, right? Just wanting to be sure before I track down a replacement ECU. There was one connection I didn't check that related to the telescopic column ECU...didn't feel like tearing into the car further at this point. Could that connection, which seems to relate to memorizing the mirror locations, have any effect on basic mirror functionality?
Old 10-14-07, 08:10 PM
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sonyman
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I can't answer your question about the telescopic ECM, but my guess would be that it's not the culprit if the telescopic wheel works as it should. If you end up needing the power mirror ECM, try www.car-part.com to find a good salvage unit.
Old 10-15-07, 08:24 PM
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ttyR2
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Ordered a used ECU for $40 from a place in Colorado. Here's hoping it works :-)
Old 10-18-07, 05:18 PM
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ttyR2
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Received the used PM ECU and the mirrors work again.
Old 09-12-08, 09:01 AM
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LILEVO
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Where is the PM computer located?
Old 09-12-08, 10:49 AM
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BR_blake
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Originally Posted by LILEVO
Where is the PM computer located?

x2

because my power mirrors are not working either. I would love to be able to set them to my memory seats.
Old 09-12-08, 07:48 PM
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ttyR2
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Behind the glove box. The Toyota diagnostic information was invaluable for troubleshooting the issue. Well worth the $10/day for the pdf downloads.
Old 12-18-11, 05:20 PM
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Dubbayoo
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Originally Posted by ttyR2
Neither of the power mirrors work in the car. I downloaded the repair manual from TIS (definitely worth the $10, thanks LexLS!) and went through the troubleshooting procedures for the mirror system. It would appear that the power mirror ECU is defective. I checked connectivity for the switch assembly (all switch functions check out) and power to the ECU. When triggering various functions using the switch, no output voltage is recorded from the ECU. If that's the case, it can't be an issue with the power mirror motors or anything else, right? Just wanting to be sure before I track down a replacement ECU. There was one connection I didn't check that related to the telescopic column ECU...didn't feel like tearing into the car further at this point. Could that connection, which seems to relate to memorizing the mirror locations, have any effect on basic mirror functionality?
What/who is TIS? I don't see a link on lexls.com for repair manuals.

(yes, I know this is an old thread but if I make a new one someone tells me to search so I did)
Old 12-18-11, 05:37 PM
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toyota information services.
Old 12-21-11, 04:22 PM
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Dubbayoo
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My mirrors aren't working either. A dealer said I needed a new mirror switch but they were no longer available. I see some on Ebay. I wonder if that part is all I need and more importantly, easily changed?


*Edit - It's not the mirror switch. Now I'm told it's the mirror ECU.

Last edited by Dubbayoo; 01-16-12 at 02:51 PM.
Old 01-16-12, 09:51 AM
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What does ECU stand for and is this the same thing?

http://www.ebay.com/itm/1990-1994-Le...sories&vxp=mtr
Old 01-16-12, 02:21 PM
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Celsior1uz
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Originally Posted by Dubbayoo
What does ECU stand for and is this the same thing?

http://www.ebay.com/itm/1990-1994-Le...sories&vxp=mtr
ECU stands for (electronic control unit)
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