Where is the backup/reverse switch or relay for a 2003 Prius?

Discussion in 'Generation 1 Prius Discussion' started by violinguy, Feb 25, 2013.

  1. violinguy

    violinguy Junior Member

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    Hello,
    I have recently joined Priuschat and love the resources and wealth of info owners can find from fellow DIYs like us! I have an issue with my 2003 Prius. The reverse lights do not turn on when I put the vehicle in R. Checked the bulbs and they are fine. Checked all the relay (fuse) boxes and didn't find any burnt fuses.

    I have a Haynes Manual and other than a circuit diagram, there is nothing that I could find about the location of the backup light relay. By the diagram I can tell that it is connected to a "HOT IN RUN or START" circuit and a 10 A fuse. Although it is useful for showing the wire routing, it doesn't tell me where it is!! Thank you all for any help you can offer!!

    Frank,
    Owner of 2005 Prius with 250K miles and a 2003 Prius with 169
     
  2. ChapmanF

    ChapmanF Senior Member

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    The real wiring diagram manual will give you much more complete information than something from Haynes. You can view it online at techinfo.toyota.com for a small subscription fee (I think two days is about $15; some people do the two-day subscription and download material for future reference) or you can get it paperbound for $60 via the distributor, helminc.com.

    Mine is not in front of me at the moment, but I would not be surprised if the relay in question turned out to be located within the body ECU.

    Hope this helps,
    -Chap
     
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  3. violinguy

    violinguy Junior Member

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    Yes, I did find a website (TRD Parts Center) that clearly indicated it is under the instrument panel in the body. By the difficult to tell diagram, it appears it's around the steering wheel which would make sense since the shifting lever comes right into that point. Now I just need a photo so I can tell what I'm looking for in there!
     
  4. violinguy

    violinguy Junior Member

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    Thanks very much Chap! I did your suggestion and went to techinfo.toyota.com. Got a 2 day membership and VOILA! they had a pic of the location and how to test. To get to it:

    1) open glove compartment
    2) remove plastic restrainers (right and left sides-turn and pull)
    3) Locate small black cube-like plastic thing (mine has jd141w1-12V along with some other stuff written on it"
    4) using a flathead screwdriver push the tabs in to unhook the wiring harness that it's attached to
    5) pull out the black cube of it's harness
    6) test continuity (ohms) using a basic multitester
    7) Test both pairs of prongs (the one's going horizontal and the vertical ones). According to the instructions, they should both show continuity (0.0 or closed circuits).
    8) Install in reverse
    BTW: the cabin air filter can easily be removed and replaced/cleaned at this point as well!

    Hope that helps others who don't have to go through a few weeks of frustration finding this!!!
     
  5. violinguy

    violinguy Junior Member

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  6. ChapmanF

    ChapmanF Senior Member

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    Glad you found it. Did that tell you why your backup lights don't come on? Was the relay bad?

    -Chap
     
  7. violinguy

    violinguy Junior Member

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    Relay was bad, took 30 seconds to change and put back together! Tested and the lights came on! Toyota took me for $78!! There has to be a cheaper source of relays out there!!
     
  8. 3prongpaul

    3prongpaul Hybrid Shop Owner, worked on 100's of Prius's

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    Relays rarely fail. Find a used one on Ebay or from a recycler. I've got bags of good used Gen1 relays. $10 each including priority mail if anyone needs one. Just pmail me.
     
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