combination meter repair - DIY

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Ultanium, Jan 20, 2016.

  1. caravan2429

    caravan2429 Junior Member

    Joined:
    Sep 21, 2018
    64
    18
    0
    Location:
    Sandy, UT
    Vehicle:
    2007 Prius
    Model:
    II
    How do your guys program the correct mileage if there is replacement from another combination meter? Is there easier way to do? I know EEPROM, but don't have tools to do that.
     
  2. oregoncarl

    oregoncarl New Member

    Joined:
    Sep 15, 2019
    2
    3
    0
    Location:
    Oregon
    Vehicle:
    2008 Prius
    Model:
    Two
    Well, my "repair" lasted for about a month, then it went dead again. I suspect that I maybe didnt get a good connection on all the pins of the IC, So replacing that was maybe ambitious for someone without more electronics experience and better gear. Good news is that Texas Hybrid Batteries still does refurbished modules, and that worked out great. I have now pulled the dash off so many times that I was able to strip it, replace the meter, and put it all back together in 45 minutes!
     
    donbright and jerrymildred like this.
  3. Scholztec

    Scholztec Junior Member

    Joined:
    Nov 30, 2019
    4
    1
    0
    Location:
    Phoenix
    Vehicle:
    2006 Prius
    Model:
    Two
    Long time lurker, finally joined the site.

    My girlfriend’s 2006 has had intermittent failures that have become near-constant, so it’s time for me to try this fix.

    I know the 3 SM caps from the other posts. I’m nowhere near skilled or ambitious enough to try the regulator itself. However, since I’m in Phoenix, AZ (just past the surface of the sun in summertime), I’d like to replace the through-hole electrolytics at the same time (I can see 7 in the pics posted here). I can’t find any listing of what those caps are. They may be fine, but since disassembling the dash seems like a PITA, I’ll replace them if I’ve already gotten it apart. I’m trying to minimize downtime, as this is her only car, so I’d like to order them in advance.

    Does anyone know the values of the seven electrolytic through-hole caps on the board? Thanks!
     
  4. OBJUAN

    OBJUAN Member

    Joined:
    Aug 17, 2017
    96
    49
    0
    Location:
    canada
    Vehicle:
    2005 Prius
    Model:
    Base
    the thru hole caps will have the value printed on each. Just upgrade the temperatures to 105C.
     
    SFO likes this.
  5. Scholztec

    Scholztec Junior Member

    Joined:
    Nov 30, 2019
    4
    1
    0
    Location:
    Phoenix
    Vehicle:
    2006 Prius
    Model:
    Two
    Thanks very much for the reply. I’m looking for the values in advance, since I can’t afford to have her car down for a week while I wait for parts. There’s a lot of pictures posted of the board here, but none of them are close enough to read the values of those caps.


    Does anyone know the values of the seven electrolytic through-hole caps on the board? Thanks!
     
  6. oldtechaa

    oldtechaa Active Member

    Joined:
    Dec 28, 2018
    320
    209
    0
    Location:
    KY
    Vehicle:
    2008 Prius
    Model:
    II
    Yeah, Scholztec just didn't want to have to take it apart first. If someone like Matt had some cap values he could list, it'd probably be the best. I haven't taken mine apart yet, although I had my third failure to start today, my first this winter.
     
  7. VFerdman

    VFerdman Senior Member

    Joined:
    Jul 5, 2017
    1,138
    1,155
    3
    Location:
    Western Massachusetts
    Vehicle:
    2007 Prius
    Model:
    Three
    I have just completed the repair after a single incident of meter going dark and car not powering off without holding the power button down for 5 seconds. I did not want to wait for it to fail in the middle of the winter and used the last warm November day last week to pull the dash and replace the C3 cap. It's a 100uF SMD cap that I replaced with a 220uF through hole unit. I just soldered it to the SMD pads and all seems to be well so far. I do not think it's necessary to re-cap the whole meter. C3 is the only one that tends to go and I think it's because it was sized too small at 100uF. The tiniest degradation of that 100uF and the circuit fails. So installing a 220uF in there ensures it will not fail any time soon. I have not heard of any other failures of the meter, but that is not to say there aren't any others. In any case, pulling the dash is really not that difficult, especially if you've done it before. Everything comes out very well and goes back in relatively well also. I had a bit of trouble getting the dash to go home because I did not notice that the leading edge of it caught on the windshield vent . Once I figured it out, everything snapped back in like magic.

    One thing of note. Once I had everything together and the car started just fine, I had a red triangle lit up as well as the little red car with exclamation point on the MFD. Turns out that after the passenger air bag is disconnected and reconnected, as is the case in this procedure, the systems wants to do a self-check on it. Well, the self-check is not possible until there is a passenger in the passenger seat. So once I sat in the passenger seat and the SRS system did its thing, both warning lights went away and everything ran normally ever since.

    I would not be over-thinking it with re-capping, just get the problem resolved and keep on driving. I have not heard of those through hole caps failing. It's the C3 SMD 100uF cap that goes ever so slightly out of spec and that is why the problem is so intermittent. With time it gets less intermittent as the cap slides further from the 100uF needed for the circuit to operate. 220uF works great and is probably never going to degrade to below 100uF.

    Here is a picture on a through hole 220uF cap soldered in the C3 spot.
     

    Attached Files:

    #227 VFerdman, Dec 2, 2019
    Last edited: Dec 2, 2019
  8. OBJUAN

    OBJUAN Member

    Joined:
    Aug 17, 2017
    96
    49
    0
    Location:
    canada
    Vehicle:
    2005 Prius
    Model:
    Base

    They are all nichicon 105C, four 22uf-63v 6x12mm, two 100uf-50v 8x12mm, one 330uf-35v 10x16mm. The surface cap 100uf/16v gets upgraded to 220uf-35v, a thru hole cap can go in there. I also put another 0.1uf 0603 (C5) ceramic cap on top of the one already there to double it. good luck
     

    Attached Files:

    Landon51, VFerdman and SFO like this.
  9. Scholztec

    Scholztec Junior Member

    Joined:
    Nov 30, 2019
    4
    1
    0
    Location:
    Phoenix
    Vehicle:
    2006 Prius
    Model:
    Two
    You are a life saver. I love you. Thank you so much!
     
    SFO likes this.
  10. OBJUAN

    OBJUAN Member

    Joined:
    Aug 17, 2017
    96
    49
    0
    Location:
    canada
    Vehicle:
    2005 Prius
    Model:
    Base
    Doubt those caps are a problem, high quality high temp.
    The surface electrolytic caps are the problem....
     
    SFO likes this.
  11. Scholztec

    Scholztec Junior Member

    Joined:
    Nov 30, 2019
    4
    1
    0
    Location:
    Phoenix
    Vehicle:
    2006 Prius
    Model:
    Two
    I completely agree. I’m almost certain that they’re fine.

    This car spent 10 years freezing to death in subzero IL winters, and the last 3 years roasting in the AZ heat. I’m surprised that it took this long for C3 to fail. While I’m sure the other caps are fine, there’s two reasons I’ll replace them:
    1. It’s an extra $3 in parts where I’m already buying.
    2. I’m going to have the dash apart anyway.
    It’s like the C5 cap... probably don’t need to replace or add if you’re fixing C3, but if you’re already in the neighborhood, why not.

    Speaking of C5... my soldering skills are... not excellent. I’ve tackled minor repairs before, but nothing that tiny. Watching YouTube videos of people replacing C3 (as well as success stories here) leads me to believe that I can handle the bigger parts. I’d like to add on to C5, but I’m afraid of screwing it up. I have a tiny 20-watt RadioShack iron. I have some small tips for it, but those 0603s are microscopic. Do you have any suggestions for technique, or should I just leave it alone?

    Thanks again for all your help. This forum has been invaluable!
     
  12. VFerdman

    VFerdman Senior Member

    Joined:
    Jul 5, 2017
    1,138
    1,155
    3
    Location:
    Western Massachusetts
    Vehicle:
    2007 Prius
    Model:
    Three
    A word of caution. You may end up replacing excellent quality caps that Toyota chose with some inferior ones from wherever you are buying. Also soldering adds corrosive flux to the board. When done at the factory the boards are cleaned before being put in service from said flux. I doubt very much you will clean the flux after your replacement and it can and will in time corrode the contacts. Just saying. Some things are best left undone, even if it seems like a good idea to do them. I would (and did) do the absolute minimum soldering necessary to get the car working again and leave it be. Otherwise it will be: "If it ain't broke fix it till it is".
     
    jason6, fragglestickcar and SFO like this.
  13. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,181
    6,285
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    Totally agree especially since OP says his soldering skill is not high.
     
  14. pasadena_commut

    pasadena_commut Active Member

    Joined:
    May 2, 2019
    419
    135
    0
    Location:
    Southern California
    Vehicle:
    2007 Prius
    Model:
    N/A
    Flux yes, not necessarily corrosive flux. Rosin core solder, the type used for electronic circuits, is not corrosive. However, the rosin can make a compound which looks like copper corrosion. Acid core solder or pure solder with flux paste as is used for plumbing or metal work are indeed corrosive. See this article:

    https://www.kester.com/Portals/0/Documents/FAQs/GreenCorrosion_Global.pdf

    Elsewhere on that site they say:

    Rosin Flux Removal: The question that frequently comes up is, do rosin flux residues need to be removed?
    Rosin flux residues are non-conductive and non-corrosive. Under normal circumstances they do not have to be removed from a printed circuit assembly. Rosin residue removal would be for cosmetic considerations. In an environment where the working temperature of the assembly will exceed 200°F the rosin residues will melt and become conductive, in these situations flux removal is required.

    So I would just use a good quality (ie, from a known manufacturer, not who knows what from who knows where) rosin core solder and call it a day. No cleaning.

    I think the problems a beginner soldering a board like this might reasonably encounter are lifting a pad (too much heat) or burn some other component (by touching it with the soldering iron tip.) If through hole components are being removed a solder sucker or desoldering tool should be employed. Using both an iron and a sucker requires more coordination than using one of these:
    [​IMG]
     
  15. Vinny Boom-Bots

    Vinny Boom-Bots New Member

    Joined:
    Jan 12, 2020
    1
    1
    0
    Location:
    Rhode Island
    Vehicle:
    2007 Prius
    Model:
    ----USA----
    Hello everyone I am new here and have been trying to read all the posts about this repair. I am completely stuck. I switched out the 100uf 16v sm capacitor with a 200uf 16v radial capacitor (no name brand off eBay). Upon starting the car back up after the install my odometer came back on. It was not reading the fuel level and on the MFD the 2nd consumption screen would not show any data on the bar graph. It was showing the current MPG. The odometer went blank and then came back on as I was test driving it around the block. The fuel still was not registering and also the bar graph was still not showing data. The odometer went blank again and when it came back on the fuel level was showing correct but once again the bar graph was not registering any data. I parked the car and turned it off. I then came back out maybe an hour later to head to the store, started the car and the odometer came on as it should. I tried to disconnect my battery to "reset" it but the screen was still blank. I decided to take the entire dash back apart, remove that capacitor and solder a new one on. I was not sure if maybe it was a bad capacitor or if I accidentally over heated the capacitor while installing or bad connection. I put everything back together again with the new 220uf 16v radial capacitor. The car started and the odometer came back on. I happen to open my driver door and the odometer went blank again.

    Would I be missing another capacitor that needs to be replaced?
    Would the no name capacitor be the issue?
    I was told on a FB Forum that the 16v is too week and to use a 100uf but 25v not the 16v

    I appreciate everyone's time. I am trying to avoid sending it out for repair but if need be I will send it out to someone who knows what they're doing. I am just going off of what I have researched.
     
    VFerdman likes this.
  16. VFerdman

    VFerdman Senior Member

    Joined:
    Jul 5, 2017
    1,138
    1,155
    3
    Location:
    Western Massachusetts
    Vehicle:
    2007 Prius
    Model:
    Three
    Never ever use no name caps from ebay for anything that you care about working. There is simply too many junk parts around and knwon good parts are really cheap. Like REALLY cheap. I am not sure what the motivation to use no name caps would be, even. That said, the cap is probably okay short term (but who really knows?). Most people go up to higher voltage rating than 16V when replacing, but a good quality cap of 16V rating should last another 10 years (like the one you took out), so I voltage rating is not the issue, though I would go with a higher voltage rating. Electrolytic caps vary in quality very widely. So getting a good quality part is important and not very difficult. Just go to Mouser, Arrow, DigiKey or any other supplier you like and order a few caps from them. You will pay more for shipping than for a count of 10 caps, most likely, but such is life. Then you will have a quality cap that is within 20% tolerance or so. I would still go with higher than 100uF as that seems to be very close to what is required and larger values work just as well. As the caps get older they loose some of that value and are +/-20% to begin with. So your 100uF cap can easily be 80uF and in a few years can become 60uF, etc. I do not know at what value of this cap the problems begin to appear, but it seems that the cap you put in there may just be on the verge of the correct value. You need to replace it with a known good cap of greater than 100uF and go with the higher voltage rating also. Then make sure the polarity is correct and your solder work is neat and didn't damage other things in the vicinity. I think you are pretty close to the goal, but your choice of caps may have been poor.
     
    jerrymildred, edthefox5 and SFO like this.
  17. edthefox5

    edthefox5 Senior Member

    Joined:
    Jul 25, 2007
    9,417
    4,412
    0
    Location:
    Clearwater, Florida
    Vehicle:
    2007 Prius
    Model:
    Two
    Exactly.

    Mouser sells excellent LOW ESR Panasonic caps.Caps that specially have very low esr. No name caps are a guaranteed return to the scene of the crime.
     
    donbright and VFerdman like this.
  18. jason6

    jason6 Junior Member

    Joined:
    Sep 21, 2013
    6
    4
    0
    Vehicle:
    2009 Prius
    Model:
    Two
    I just added a 100uf cap and it fixed the problem. Before adding the combination meter would not turn on unless I turned on the lights first (that sometimes fixed the problem). After adding an extra 100uf cap instrument panel turns on every time, problem fixed. Thanks.

    Perhaps I missed some, but in reading the chat I did not see mention of the following related to the combination meter:

    * If you have a problem with the meter, before it is fixed, and if you have sks (smart key system) turn off the sks and leave it off. When the sks is enabled you may not otherwise be able to turn off the car without unplugging the battery.

    * There are many ebay listings to repair the meter, many for $50 and they offer warranties. I have heard on the chat that your car will be down while waiting for the return repair via mail. That is not true. You can operate the car without the instrument panel installed, just make sure to attache the power button and park button and you can drive without the panel in place.

    * Removing and replacing the cap is one option, but if you dont feel you have the skill to do this surface mount rework, you can of course tack on an extra cap - in my case 100 uf. This of course has been mentioned in the chat. What has not been stated is that on both sides of the cap are vias with thru holes that are directly connected to the cap pads. Make sure you ohm out the vias to verify you have the right ones. So you can use a standard non-surface mount cap and insert it into the correct thru holes and of course then fill the vias with solder. That worked fine for me and was easier than tacking an extra cap onto the pads of the existing cap.
     
    SFO likes this.
  19. pasadena_commut

    pasadena_commut Active Member

    Joined:
    May 2, 2019
    419
    135
    0
    Location:
    Southern California
    Vehicle:
    2007 Prius
    Model:
    N/A
    I would be a little concerned when going that route that the older cap would continue to degrade to the point where its internal resistance also dropped (because it corroded and shorted out internally). The new cap isn't going to help if the old one shorts it out. Conversely, you might get lucky and the old capacitor could fail "open". Anyway, replacing the original would be best, if at all possible.
     
    jason6 and VFerdman like this.
  20. jason6

    jason6 Junior Member

    Joined:
    Sep 21, 2013
    6
    4
    0
    Vehicle:
    2009 Prius
    Model:
    Two
    So would you
    So would you replace all the caps on the board - if not why would you think this one is more likely to fail? It was undersized originally and the claim is that caps get weaker over time. If it ain't broke, fix it anyway :) ?
     
Loading...