combination meter repair - DIY

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

  1. Ultanium

    Ultanium Junior Member

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    I purchased a 2006 Prius, that has the dreaded dark dash, and the warranty was never completed to replace it. In searching this forum, and all over the net, I cannot find any specific details about what the problem is exactly, in order to fix it myself. PC member pEEF has erased nearly every post he made, concerning the issue, and has stopped doing the $75 repair, that he says is "electro-mechanical". Another interesting forum post claims that there was a change from lead based solder for ROHS specs, during the mid 2000's, and that is the issue. Yet another, says it is bad caps, which anyone can purchase for a couple bucks from Mouser, and put in themselves. Why is there such secrecy involving this repair? We have plenty of details on repairing the MFD, but not one detailed post on the CM? So here, in this thread, I will detail my experience in trying to fix my own CM, and welcome any input from others that have also tried. If I fail, I will send the darn thing off, and at least have some before and after pictures, to see what they fixed, and share it with everyone.

    Tj
     
  2. Ultanium

    Ultanium Junior Member

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  3. Ultanium

    Ultanium Junior Member

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  4. Ultanium

    Ultanium Junior Member

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  5. Ultanium

    Ultanium Junior Member

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    The symptoms should help determine where the fault lies. We know the rear hatch will refuse to operate, the check engine light still works, as do the blinker indicators, when the dash goes dark. Unplugging the white plug at the 12V battery for a minute, resets something, that will often allow the CM to work again, which leads me to believe it is a capacitor that is getting too weak, in the power circuit. Time to tear the dash apart, and put the multi-meter to work.

    Tj
     
  6. andrewclaus

    andrewclaus Active Member

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    Have fun with it. If you can't get it, there's at least one vendor on eBay who will fix it for about $115.
     
  7. m.wynn

    m.wynn Senior Member

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    I recall this being identified as a bad solder joint(s). Can't recall if it was pEEf, specifically, but someone definitely had pics posted clearly showing the offending solder bead(s). pEEf doesn't seem to come around anymore, either, which is a substantial loss to PC, imo. Sorry I'm of no help. I've also been unable to locate both the words and pics which once documented this issue. My cynicism certainly supposes the lawyer word had something to do with it...

    Luckily, I was able to get our '07's replaced under the ZTV enhancement. Best of luck and please share your findings!!
     
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  8. valde3

    valde3 Senior Member

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    I couldn’t find pEEf actually giving the exact information but found this:

    “The first problem is a design fault in the start-up circuit that controls reset on the fujitsu microcontroller. I have isolated the problem and have been able to re-engineer the circuit by adding in a new component. This insures it will never fail to start properly, so this "cold" problem will not recur. The original circuit is marginal and gets worse during extreme temperatures, and as the car continues to age. Once the problem starts it usually gets worse until eventually the display never comes on at all. All boards will eventually experience this problem, as it is a design fault!

    The other problem is caused by simple electromechanical faults related to vibration and temperature cycling. It's an industry-wide issue that's cropped up in many places since the RoHS came about. That's when they removed the lead from solder alloys, and an unintended side-effect is that products subjected to vibration and wide temperature extremes are more likely to fail due to a more brittle solder alloy.”
     
  9. Ultanium

    Ultanium Junior Member

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    The pictures would be a great help! I have searched Archive.org without success, so maybe someone saved them, and will share. I agree, Phil seems to have given up on PC, he had so many posts and shared his knowledge with everyone. I really hope someone didn't burn him, and run him off.

    Tj
     
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  10. valde3

    valde3 Senior Member

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    Did you actually find any topic where the pictures would have been? Because it seems that first pEEf was not telling how to do the repair because he repairing them for money and later he was just telling everybody to use the warranty.

    But maybe you could track one unit that he has repaired and you could probably spot his work pretty easy from it?
     
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  11. drew935

    drew935 Member

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    Please post any updates you have on the repair Ultanium. I think that it's a simple fix with replacing and resoldering the new parts.

    I was planning to send out my niece's 05 cluster with the eBay unless I can do it myself.
     
    #11 drew935, Jan 29, 2016
    Last edited: Jan 29, 2016
  12. tony2ltr

    tony2ltr Member

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    I am very interested in how one can diy thus repair. Thank you,
    Anthony
     
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  13. scargi01

    scargi01 Active Member

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    Here is what I know:

    1) When the temp drops my combo meter won't come on almost 100% of the time. You can tell if it isn't going to work simply by opening the door. If the open door warning light on the dash doesn't come on when the door is open the combo meter isn't going to work.

    2) I use the key FOB trick (Foot on the brake, lock, turn on lights, foot off the brake, lock) to get it back on, which works about 95% of the time. I have had a few times where it didn't work the first time but it did on the second time. If it doesn't work then there is nothing you can do until the car sits off for a period of time (not sure how long, but at least a couple of hours). If the meter doesn't work the car won't completely shut off. I have to hold down the button for at least 3-5 sends before the car turns off, and then the MFD doesn't turn off. To turn off the MFD, I put the key in the slot and remove it, which seems to turn off the car completely.

    3) If it does work I make sure to put the heat on the upper and lower vents. I don't know if this does any good or not but the idea is to warm up the combo meter.

    4) During the day, depending on the temp, the combo meter could go out again when the car is turned off. It never goes off while driving, only after it has been turned off.

    5) Don't know if it related but the cruise control quit working about the same time the combo meter started doing this.

    My question: If the combo meter can be "fixed" by performing the key fob process does that indicate it is some type of software issue? If the temp causes the combo meter to lose it's mind then is the key fob trick essentially "booting" the board?
     
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  14. exstudent

    exstudent Senior Member

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    You do realize, that the combo meter for 2004- certain 2009 Priu, has a Warranty Enhancement, for this problem?

    Warranty is for 9years (no mileage limitation), from the first date of first use (essentially when the very first owner purchased the vehicle).

    You should be able to goto any Toyota Dealer and tell them your combo meter is bad (intermittently works and must depress the power button to shut off the car).
     
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  15. dolj

    dolj Senior Member

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    So, scargi01's 2005 will be at least a year (coming up for 2) out of the extended warranty.
     
  16. scargi01

    scargi01 Active Member

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    Yes, I am out of warranty. Should have stated that above. Went to the dealer previously and they called Toyota, who said they would knock $100 off a $750 replacement bill. I have seen the videos online about how to replace the meter and that is probably what I will do when the weather warms up. I don't have a heated garage I can put the car in and I don't want to try unsnapping a bunch of plastic trim parts in cold weather. Anytime I touch a piece of plastic in cold weather it breaks.
     
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  17. drew935

    drew935 Member

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  18. scargi01

    scargi01 Active Member

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    Thanks the tip. Did they send you instructions for removing and installing the new one?
     
  19. drew935

    drew935 Member

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    No. That's not part of their job. The repair is their part and the removal and installation is ours.
    Here's instructions if you need them:
    Combination Meter Removal
     
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  20. NotScott

    NotScott New Member

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    I have an 05 that just went dark. Too bad this thread isn't followed through to a complete fix. If a guy on eBay can do it for $100 it should be pretty easy. Gonna see if I can figure out the fix. If so will post the actual fix detail here.