combination meter repair - DIY

Bill,
The VIN is not programmed into the meter. Just swap them out and you'll be good to go. Great job finding the meter that matched your odometer, that's the hard part.

Matt

 

You can save your combo meter by just using a windshield shade. I never get out of the car unless it's in the window. The one they sell here at the PC SHOP the heat shield is the best. My first one lasted 6 years. It's insulated and form fitted to the Prius windshield. Good tint job helps too.

Reducing cabin heat will prolong the hybrid battery too.

 

Hi Matt,

Thanks for the response. I have replaced the combo meter and have had it running for a week. All appears to be well.

Thanks again!
Bill

 

My VIN number was not included in the extended warranty for the combo meter.

So, I finally got around to doing this repair because my car got to the point where I could not shut it off normally when the display was blank. I only changed the capacitors because I felt like changing the IC was too risky considering the tools I had on hand. I don't think the problem is the IC, but won't know for sure until the next cold day, which is not likely to be for 5 or 6 months. The whole job took about 4 hours, including changing the caps.

I will say this. If you are not a person that regularly works with this type of stuff and all you have is a cheap soldering iron, you should probably just go ahead and purchase a rebuilt meter. You should have a Metcal soldering iron (or equivalent) and a binocular microscope. Solder wick is also useful for this job. Take the caps off, wick the solder off the pads, then pre-tin the leads on the new caps. Put solder on one pad and hold the cap in place while you reflow the solder beneath it. After that you can flow solder under the other lead.

In addition to changing the caps, I reflowed any suspicious looking solder joints (there were many), on the bottom of the board.

To change the IC (which I did not), you would need a hot air tool to reflow all the pins at once. You could also reflow one pin at a time and pry them up with a pair of fine tweezers - but very risky. There is also some stuff called "Chip Quik" that can be used to lower the reflow temperature of the solder, and you can glop it over all the pins and reflow the entire chip with a soldering iron. If you use the latter method, then you need to really clean the pads off well before installing the new chip (reflow one pin to hold the chip in place, then flow solder under each of the other pins).

Interestingly, my combo meter had the blue pooky on the IC pins just like the NEW meter previously posted in this thread, but it still had the 100uF cap for C3. The blue pooky is a rubber-like material and can be peeled off with an exacto knife.

All of the caps I removed looked like they were in good physical condition. I measured them - they are all within tolerance (C3 is definitely 100uF). I even put them in the freezer and measured them cold, and C3 only dropped to about 95uF. So, unless there is a problem with the IC, then the real fix here is setting C3 to 220uF. Perhaps some changes in the IC when it's cold also, which in combination with the 100uF cap causes the circuit to malfunction. We shall see when the cold weather comes.

I was really glad to see the display light up when I pressed the power button, I will tell you that.

 

Do you know if the vehicle is useable while the meter is being repaired ?

 

I have 2008 Prius. My combination meter worked fine, when the 12V battery was at 12.7V or higher,
and went blank, when the voltage was lower. I took the unit out, and it was already worked on.
I have soldered wires on the +5V and 0V (5V) around C3 capacitor, I have put the wires through opening for buzzer, and just outside I have soldered a 22uF, 25V tantalum capacitor. I have used brown wire for positive 5V, and blue for 0V (5V). The C3 alone was 100uF, total capacitance of the 2 capacitors in parallel is 122 uF.
This fixed the problem, and the combination meter now works at 12.5V (12V battery voltage)
The 12V battery is a normal small car battery, not the one from Toyota. I didn't solder directly to C3, but to
the +5V and 0V copper pads. Watch for polarity, electrolytic and tantalum capacitors are polarized.
My next step will be replacing all lights with LEDs. I would like to give credit and thanks to other posters, who did all the research into the combination meter.

 

Thank you again to all who contributed to this thread. I just successfully replaced the regulator and the three capacitors on my combination meter. I ordered all the parts from Mouser just as described for about $15 for enough parts to do 3 meters.

At first I was not going to replace the regulator because of the blue goop that was around it, But I found that after the goop was heated by my hot air rework station, it came off very easily with isopropyl alcohol and a Q-tip. As with all surface mounted devices, you just need to make sure the regulator is on correctly and properly centered on the solder pads.
I was overjoyed to see the display come up without issue and I smile every time it lights up knowing I saved a ton doing it myself.

 

I know this is a very old post and the link no longer works but I was wondering if the repair has lasted?
anyone dealing with a company still doing these repairs.. let me know thanks

 

anyway to list the parts needed? id like to order them before ripping the car apart

 

Funny you should mention that. I was just about to post the parts I ordered. Hope the links show through.

726-TLE4278G
TLE4278G
Auto Linear

647-UUD1C221MCL
UUD1C221MCL1GS
16volts 220uF

667-EEE-HA1V331P
EEE-HA1V331P
Al Lytic Cap SMT

667-EEE-HA1V100R
EEE-HA1V100R
10uF 35V

 

thanks... ill give it a try ... what could go wrong

 

Here's the company's site:
Module Repair Pro INC

 

Try using acetone instead of alcohol.. It is the best pcb cleaner. Cuts much better than alcohol. I go over solder joints with acetone and wooden q tip and they look factory. Have for 30 years.

 

Thank you for the info, ordering parts to fix my 2006 CM.

 

So I'm going to have to do this on my 04 (bought 11/03), which has been in FL, outdoors, all its' life, and my wife almost never uses the sunshade, and didn't like the carpet dash pad so we gave it away...

I've been driving it for a few days as I work on repairing damage from a delaminated tire on my 06, and this CM issue is MADDENING. I even put a circuit breaker on the negative battery cable to cut power, and that worked yesterday morning/afternoon, but last night picking her up from work, NOTHING worked but pulling both plugs on the positive terminal, and that bigger one is a REAL bear to pull out. I'm thinking of putting the circuit breaker on the positive side, but I don't have insulators to cover its' studs, so I'd have to go crazy with 3M 33 to cover the exposed bolts to feel comfortable with it while I order the parts.

Those that have done the replacement - how many have replaced only the caps? I'll only have a cheap soldering iron, desoldering pump, and wick, so I'm thinking caps only.

I've replaced electrolytic caps on well over 100 computers and car ECUs over the years, but SM stuff often drives me nuts, as I don't have an iron to handle the smaller stuff. I HAVE done some SM replacements in the past, but really hate them. Though by the pics, at least these are full-size caps.

 

And another question - can I use an 06-09 board in the 04-05? I realize it won't have the READY on it, but I've always found it annoying stepping from the 04 to the 06 and having the CM "backwards" between them. And I might be able to get a working 06 cluster cheaply.

 

from what I understand 04 and 05 are the same then 06 to 09 are the same.. just hit a salvage yard LKQ sells them for under $50, I scored one for $24 when they did their 40% off sale .. of course mine has not crapped out since but Im going to hang on to it just in case..

 

Yes, you can. Another benefit of doing it is that the CM will roll passed 299,999 miles.

See the link in my signature titled "Combination Meters that stop at 299,999 miles, who's affected and what you can do about it." which details what's involved.

Hope that helps.

 

Yes it does! If I can get it cheap enough at the local boneyard, it will be worth grabbing for a backup for both my cars, if all I have to do is pull an SM LED if it is going in the 04.

 

Hello. Looks like my 2005 combo meter issue has just progressed past intermittent and will have to be dealt with. It's a handy household so I lean toward DIY installing a rebuilt one, but I have a concern with the dash breakdown. This car has been in southern Calif its whole life and plastic tabs tend to get crispy here. Those wheel cover ones just totally break off, and also we were in the headliner once and had to order a bunch of replacement connectors. Are we likely to break off tons of connectors and need replacement vents, pillar garnishes, etc. etc.?