Well, it happened to my Gen 2. Combination meter malfunction.

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by VFerdman, Nov 26, 2019.

  1. VFerdman

    VFerdman Senior Member

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    This morning I got a frantic text from my wife saying that the car won't shut off and the speedometer is not working.

    I have to note here that what I felt was not dread, but some strange feeling of familiarity with the issue, even though I have never encountered it myself. Having been a member here since I bought my 2007 Prius in 2017 I have been diligently learning about these cars as I have truly become very fond of them through my ownership experience.

    So when I read the text, I caught myself thinking "I know EXACTLY what this is!". It was a very good feeling and I owe it mostly to this forum (You Tube also helps). My wife did figure out that holding the power button for a long time shuts off the car and when she came back to it, everything seemed normal again. So the bad 100uF cap on the meter is beginning to go. When I have a chance I will be dealing with it by pulling the meter out and replacing the cap (C3, I believe) with a 220uF one. Fortunately I am totally comfortable with a soldering iron (have been soldering since I was 10 years old and tinkered with home made radio receivers). I also have plenty of salvaged and new electrolytic caps around (I have a hard time throwing away salvageable electronics and my wife calls my collection "the wire museum"). Is there anything that anyone has learned from replacing their own cap? It seems pretty straight forward, but just in case there are some long term issues, I'd like to know. I plan to replace with a through-hole component, as surface mount is more difficult to work with. Are there vibration issues for the through-hole cap sitting on SM pads? Should I use a little hot glue to stabilize it?

    Thank you for the great forum and the fact that instead of "Oh, $hit!" I had an "Oh, I know how to fix this!" moment today.
     
  2. jerrymildred

    jerrymildred Senior Member

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    That's fun when you know just what to do. As Red Green says, "If the ladies don't find you handsome, they should at least find you handy." :D

    I have not had to replace that cap (yet) but I think I'd use some silicone or maybe hot glue to support it. Not sure what the heat might do, so I'd favor the silicone.

    Here's the link to the video I used to remove the CM --


    And here's the final step after you show your wife how great it works when you're all done.


    :D :D :D (y)
     
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  3. JC91006

    JC91006 Senior Member

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    If my wife told me this while she was on the road, I would have a "OH Shit" moment
     
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  4. VFerdman

    VFerdman Senior Member

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    Well, she was parked and couldn’t shut the car off. Then she figured out that holding the power button shut out off. So it was all safe. When she came back out of the store the meter worked again, so no issues with the trip back. In any case, combo meter failure is not catastrophic. Car will drive fine. Speedometer can be replaced temporality with a phone gps navigator. There was no reason for “oh $hit”.
     
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  5. VFerdman

    VFerdman Senior Member

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    Thanks, I watched the same video and am almost done with the repair now. Just need to test and reassemble everything.

    i am usually found very handy by the ladies. Not sure I can do a Tarzan thing. I look nothing like that without a shirt :)
     
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  6. VFerdman

    VFerdman Senior Member

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    I completed the repair last night. It was really not too difficult, mostly time-consuming dis-assembling the dash and re-assembling. Here are some beauty shots of my car without the dash and some closeups of the cap I replaced. I went with 22uF 35V can I had kicking around. I am pretty sure it was a salvaged part. My collection of new ones did not have the 220uF. I decided to not add anything in addition to soldering as there are several through hole electrolytic caps right next to this one soldered to surface mount pads in the factory. They are okay, so I figured that this will be fine also.

    One note that I am not sure I saw mentioned is that after the final re-assembly I started the car and everything was fine, except for the red triangle was lit up on the dash as well as the red car with exclamation mark on the MFD. No codes were stored in the realm that I could access with my generic OBD2 reader and I was very stumped. Then I went and sat in the passenger seat while the car was on and the airbag sensor in the seat kicked in and caused the airbag to go through its self-test cycle after which the triangle and the MFD warning went away and everything is well. I can only assume that the system sensed the fact that the airbag was disconnected and went into a self-test mode after it was re-connected, but couldn't perform it until the passenger presence sensor was activated. This is what makes sense to me, anyway. It is all good now and no warning lights at all. The combination meter is functioning perfectly so far. The problem was only beginning and this was the very first time we ever experienced it. I took advantage of the fact that the outside temperature was above my age (in Fahrenheit) and proactively did the repair as I really do not want to be dealing with it in the middle of the winter.

    Thanks again to this forum for the info about this issue.
     

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