I appreciate someone's opinion on this. I have an '04 Prius with 125,000 trouble-free miles. I've not even had to do a brake job; just routine maintenance and recalls/updates. Yesterday the display screen stopped working. Pressing A/C displayed something like 'cannot detect air conditioner,' or something-or-another. Today it worked and didn't work. Everything on the car works: a/c, radio, energy usage, etc. There's just a blank screen with the wheels spinning but no energy data and sometimes I can't toggle between modes. THE 12 VOLT battery shows nominally 10.6v with the car off in accessory mode. Can this be the issue? I'm going to replace it anyway (it's 8+ years old), but I like learning from problems amd appreciate anyone's detective skills! BTW, the local dealer quotes $330+ tax for the new one installed ($80 of that is labor. $250 for the battery)... Thanks!
Yes, that is an issue. Fix it before spending money on anything else. The battery price seems a bit high, if you have a bit of time you should be able to find it under $200 without labor. Search around PC for prices and for Optima Yellowtop alternatives. But if you need it today to get to work, the opportunity of cost of the delay may easily exceed the savings.
I would say that your car has two problems: 1. You need a new 12V battery 2. You need to either replace or repair the MFD. There are many posts about this.
Here's a twist... when I turn the smart key system off everything works fine; so, I've ordered the Optima battery ($184 delivered) and will see if it indeed is due to the 9 year-old 12v gel cell...
I read that entire "Prius MFD" page to where the author found a microfracture in a solder joint. Likely a cold solder joint. I once baked a laptop motherboard at around 385 degrees for 15 minutes on my EE PhD brother's recommendation to fix a broken cold solder joint in the onboard video card and it WORKED! Might that be possible here, once all plastics are separated from the electornics?
I would not recommend the action you are talking about. I would look up OP Peef on this forum and PM him he does a quick turn round repair service at a very realistic price. The car will run without the display so once removed toy can continue to use the car.
I got the Optima Yellowtop, verified its voltage as full, and installed (it was easy)... Unfortunately, the problem is still there: "Check the connection to the air conditioner" and "No audio" when I press those buttons. Scrolling through the 4 buttons works but they respond with a slight delay. Power distribution graphics show wheels spinning but nothing else... I'm wondering if it's worth opening the dash up to get to the MFD and just see if unplugging and replugging the harness will do any good. It seems kinda odd the MFD would malfunction after 8 years and 125,000 trouble-free miles!
There are many of these cases reported, so it is not a particularly isolated event. I would not think that just wiggling the wires is going to make any permanent change. Intermittent connection problems are the bane of electronics technicians. Unfortunately, it is not at all odd that these things fail, given the data from all the taxis in SF Bay area that are repaired by Luscious Garage. Baking the board sounds very risky. Getting it repaired seems like a good way to go. Autobeyours.com can help you out.
ANOTHER UPDATE: I ran the heater MAX for one hour with the dash vents closed... The display worked fine the whole time, leading me to believe that heat-expansion of that solder joint closed the fault. I am going to buy a replacement MFD and disassemble my bad one -- then bake the electronics as described earlier. I'll report back. Can anyone tell me what's the cutoff for the GOOD MFDs in the '05 models?! I'd hate to buy another bad one from a junler...
Have your EE brother look over the board first, to review for components that cannot survive that temperature. As an EE myself, I can think examples where this process is likely to work, and others containing components that will likely be damaged.
I repaired my 2004 MFD myself a couple of years ago. It is not difficult with the correct tools: Fine point solder iron (1/64 inch) Fine solder (also 1/64 inch, preferably with lead) Solder Flux pen Magnifying glass on a stand JeffD
Arrrgh... I chanced a $105 eBay MFD from an '05 (mine's an '04). It must have been from a Prius made after Toyota's 'fix' because the back is a little different. Installed I got no display at all. But... the clock works... the flashers work... So, I removed it and will send mine off for repair, but with it out there's no speedometer with the lights on! Soooo, I put the '05 one BACK in for now and will resell it when I get mine back. I'll photograph the different backs when I have them out together...
