combination meter repair - DIY

Replaced the three capacitors on my 2007 combination meter. I was going to replace the IC circuit thingy but it looked too hard and people have seemed to have good luck with just the caps being changed out. When the car started up I too had a sigh of relief when the dash lit up normally. Getting to the CM was a piece of cake with the video. Working on the CM was a bit challenging for a soldering newbie like myself. Those caps were tiny tiny tiny and I didn't have a magnifying glass or anything so I took time and once I melted the pads I started getting better (also using tweezers to pull one side of the old board off while melting the old solder seemed to work to get them off). I really hope that my work holds up! I won't know if it works until the dead cold of the Minnesota winter because that's when my old CM would not turn on (10 below zero and colder). Otherwise everything working great! Thanks to all the contributors!

Note: I'm glad I bought 3x all the parts because I had some trouble with one of the new tiny caps and had two backups to use.

 

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.

What does this mean exactly? I don't understand the lock part.

 

It took me a few minutes to work out your post, as the quote you cut and pasted was from page one and it was not obvious that it was a quote. If you quoted the post correctly, the person you quoted would get a notification, which would greatly increase the chances of getting a reply.

Back to your question, I'd presume that it meant to press the lock button on the driver's door. Which one? I'd again presume the all door lock. I guess you're like me, and don't like to presume, so, yeah, some clarification would be in order.

 

Yea, I don't know why I didn't just hit reply on that post, rereading again it says the key FOB trick so maybe it means the lock button on the key FOB?

Then as for the meter itself, I was flipping through the pages and it appears the consensus is you change the 3 caps and the meter should work well for awhile, but I didn't see which caps to order? I saw that it said to order from Mouser but is there part numbers anywhere?

 

See post #71 in this thread.

 

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This one is not a solution, it is a bandaid just to get you home.

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I'm new to the forums and cannot create a thread yet, so here my post goes
Hello, I'm fairly new to this Toyota Prius as far as maintenance comes.
I do need some guidance on correctly diagnosing this issue.
Starting a few months back I would start the car in the morning and notice the dash, power brakes and steering were not on.
Shut off the car, restart and everything would be working as it should.
Now that happened probably 10 or so times before it completely stopped working altogether.
I have paid for the dash repair and installed it with no luck.
I have replaced the 12v battery twice now just because the first battery yielded a low cranking amp output.
I can start and drive the car currently but I have no power steering, no power brakes, no power window and the dash does not show any blue dots linking the rear battery.
Thank you in advanced for you time

 

Been on this forum for over a year, but here is my first post. Have an '05 Prius Gen2 that has run perfectly since new. Now has about 104,000 kms on it.
I've read the complete thread on repairing the Combination Meter (CM), and am now going to tackle it.
My CM just suddenly died a month ago. The failure did NOT affect any other feature of the car, just no display. I tried all the tricks to bring it back to life, none worked.
I had Toyota replace the meter with a new unit for $CAN605, which seemed a good price compared to what I have read! Toyota dealer gave me the old meter to 'play with'. Only problem with the new CM is that the mileage is now at zero, though the tech did find the old mileage and write it in the owner's manual, page 2, which is specifically for that purpose.
I bought a good capacitor meter, and checked the capacitors on my old CM. Unlike all other posts I read, the 3 surface mount caps (the usual bad suspects) on my board read: C1 9.25; C2 328; C3 114 uF. So, the maximum 'out of tolerance' reading is C3 at 14%. I suspect that should be OK?
BUT, the electrolytics at the end of the board are dead. 2 have visible burst tops, and all give readings either double, or only a fraction of the stated capacitance. They will be easy to replace.
Then, C32 reads only 169uF, but should be 330uF. I don't know what that capacitor should do, but I could replace it easily.

Does anyone have any suggestions or advice on all of the above? Is there anyway, short of owning an EPROM programmer, to change the odometer to the correct mileage? Is there anyway to test the display by applying 12V and ground to the board? I cannot find a pinout for the board.
Greatly appreciate any advice.

 

Our cars do not require cranking amps... They require steady voltage to the on board computers. What kind of battery did you install? The 12v battery in your car only powers the relays and accessories, it doesn't crank the internal combination engine. We could probably be more help if we knew the year and miles of the vehicle. When you say you paid for the dash repair, do you mean you replaced the combination meter with a new one or repaired your original combination meter by soldering in new capacitors? If you can answer some of these questions, we might be able to get you closer to an explanation or even a solution. Best of luck! -Derek

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For my previous post #151- I reread the whole thread again and found a post that stated the +12V and Ground pins to power up the CM. Thank you.
As well, found out that Toyota dealers cannot program old mileage into new meters, but should have sent the mileage to the supplier in Toyota California to have them do it. I understand now it is impossible to do without removing the display unit.
Still hope to be able to repair this CM some time.

 

did you fix it?

 

Finally got around to fixing my combination meter.

I ordered the three capacitors and IC from Mouser (though I didn't replace the IC, see below):
Mouser PN Manufacturer PN Description
726-TLE4278G TLE4278G Auto Linear
647-UUD1C221MCL UUD1C221MCL1GS 16volts 220uF
667-EEE-HA1V100R EEE-HA1V100R 10uF 35V
667-EEE-HA1V331P EEE-HA1V331P Al Lytic Cap SMT


Thanks go out to Texas Hybrid Batteries for the part numbers! I can't link but you can copy those PNs into Mouser's (or Digi-Key, or whoever) website and you'll get the right parts.

I decided to order 5 each of the caps because they were cheap, and 2 of the ICs. Total was ~ $20 with shipping.

I was having occasional no-display issues - once every few months - but it glitched on me again last week and with winter on the way I wanted to get it done.

Removing the dash was straightforward, there are several good videos on how to do it. Lots of panels to take off but nothing really difficult.

Once I got the display out, I didn't see any bulging or leaking electrolyte on any of the capacitors.

The parts are difficult to replace since there isn't a lot of room to work around the VFD and the traces are heavy. I took the display in to my office & used a good soldering iron + microscope to be sure I did it right. The IC is coated with some blue goop, I elected not to replace it on the assumption that it was the capacitors that were bad and that I didn't have replacement coating to seal the new IC. We'll see if that comes back to bite me later... but based on the experience of others probably not.

Put everything back together and it works. It's only been a few days, but if it lasts through the winter without glitching I'll consider it fixed.

I measured the capacitors I took off, the capacitance values are spot on (+/- a few %) but I couldn't check ESR with the little meter I have. Sometime soon I'll hook them up to an ESR meter and see what they look like.

Good luck to all who attempt this.

 

Blue goop is just tamper proofing. it peals off (on a good day) or dissolves in isopropyl 99%.

I've replaced my caps, doubled up C5, regulator is fine and pulled the eeprom. Yep, I pulled the VFD to get the eeprom...
That may not be necessary as there is the possibility of in-circuit-programming from the bottom of the board, next time...
Still trying to find some memory mapping info to set the odo to the old CM numbers.

 

Got my combination meter fixed at KlaxonPro Hybrid Technology in Los Angeles for $160.

 

Takes 1/2hr to replace the caps and <$20 for 4 sets with shipping. Course you'll need the tools,
25watt pencil iron, 60/40 solder for electronics and anti-static workstation/protocols.
Easily a DIY project........

 

Good News Everyone! Another update....

I replaced the caps on the 09 CM unit doubling up C5 as well, just in case.
Matt at Texas Hybrid posted a list of suitable caps.
I did not replace the regulator chip, it was working fine before and the ones I
ordered have not arrived anyway. I removed the VFD and the 93C66 eeprom.
I used an SP200SE reader programmer to get an image of the eeprom and sent
it to Matt at Texas Hybrid. He edited the file with my original ODO and I put it into the eeprom.
There was a quirk with the file having the byte order swapped giving me a wildly different ODO number.
Yeah, I had to removed the VFD and eeprom again. Matt realized the byte order error and I
put the new file in the eeprom. I then soldered the eeprom and VFD back on to the CM board, again.
After confirming the ODO was correct I reassembled the panel and installed it in my 05.
I had used the 09 harness that came with the donor CM but it would not power up. Exchanged
the harness back to the original 05 and worked fine. And apparently the Canadian version of the
CM does not suffer from the 299,999 limit, Doh! I like the layout of the 09 CM better anyway.....

 

Got some pictures?