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Dash not lighting up. Instrument panel No Speedo etc.

Discussion in 'Gen 2 Prius Technical Discussion' started by SuperDave, May 25, 2017.

  1. jerrymildred

    jerrymildred Senior Member

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    If you need it, here's the video I followed to get to my CM, @Prius Dragster. Lots of steps, but none of them difficult.

     
  2. Prius Dragster

    Prius Dragster Junior Member

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    Thank you Jerry. My name is Jim, by the way. Another cold snap here in Winchester, VA last night, down to the 20's plus wind chills this a.m. Power out as well as an additional bonus, no extra charge. Couple these factors with the fact I don't have a garage, I won't be attempting a DIY on the CM anytime soon. It sounds like I can still drive the car, the nuisance aspect being that the dead digital dash may or may not kick in at any time. It is the first time it has happened to me since I owned the car (3 weeks), but no telling how often it may have happened to the previous owner. Possibly one of the unspecified reasons for selling it? I will press on with driving it and switching out with the Tundra on occasion, waiting for better weather and possibly a local contact who may be familiar with these things and will do the service for me without breaking the bank.
     
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  3. SuperDave

    SuperDave Member

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    Jim It may or may not act up again, who is to say, mine is still fine. I suspect that my low 12v battery (from sitting) triggered mine to act up when I tried to start it. If you have trouble again, check the dimmer switch and connection, I believe that either the power or ground may go through it, any problems with it could affect the display.
     
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  4. k9gmj

    k9gmj Junior Member

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    I have a 2005 Prius and yesterday I was driving around shopping, stopped for about 10 minutes and when I got in the dash was completely blank. Finally found the 15A Dome fuse was blown, replace it and everything Ok. Why it decided to blow I have no idea.
     
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  5. jerrymildred

    jerrymildred Senior Member

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    You're welcome, Jim. I understand about the cold weather taking all the fun out of working on a car. Check with Matt at @Texas Hybrid Batteries. He can give you options other than a new CM and is a member here as someone already mentioned.
     
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  6. Prius Dragster

    Prius Dragster Junior Member

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    Thanks Dave. I am not sure how to tell when the 12v battery in these cars is getting weak. No slow starter to listen to. The battery in it right now is obviously aftermarket, some discount auto parts store brand that I have never heard of. Two things I have heard about these cars: Keep the fluids and batteries all Toyota, even though they are most likely the most expensive out there. I may have the battery checked when it warms up a little. I hate to do that to the Advance Auto Parts guy when the weather is crappy.
     
  7. Prius Dragster

    Prius Dragster Junior Member

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    Will do. I have already found his website. Good information to have in reserve should I need it.
     
  8. SuperDave

    SuperDave Member

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    Jerry it looks like you have owned both the Gen 2 and 3's. How does the mileage compare between the two? I have often though about a buying a gen3, but cant bring myself to do it for now, unless the mileage is greater. I tend to get better mileage than most out of my gen2's, it must be the competitive racer in me, always wanting better performance lol.
     
  9. SuperDave

    SuperDave Member

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    The car will be your biggest indicator, I would say that if it starts fine without needing any charging you should be ok. As we all know there are no guarantees in life, and 12v lead acid batteries are no different.

    As a general comment to your situation and also K9gmj's, these cars are so complex and starting to age, that sometimes "fluke" things will happen, never to happen again (when your lucky) lol.
     
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  10. Prius Dragster

    Prius Dragster Junior Member

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    I am finding that out, Dave. It doesn't scare me (yet), but I may sign up for AAA again to be on the safe side. Not for fear of being left on the side of the road so much as for attempting home repairs that may leave me with a car half apart that won't run. Oh, and an OBD II. Definitely need to join the 20th;) century regarding that!
     
  11. jerrymildred

    jerrymildred Senior Member

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    We're getting a little off topic, but not for the first time on PC. :)

    We're on our 3rd Gen 2 Prius. And My PiP is based on the Gen 3, but it does a little better than a regular Gen 3. Each generation gets a little better fuel economy -- maybe 5-10% better. That's not enough all by itself to financially justify upgrading. I traded in my '05 because it was needing some rather expensive repairs, had 150,000 miles on it, and I was really wanting to have the PiP. (Prime would have been even better, but out of my price range.) Even with the repair costs, I'd have spent much less fixing the '05, assuming nothing else expensive failed like the air conditioner or something.

    The biggest differences between the Gen 2 & 3 that I see are (in order of significance to me):
    Positive:
    Newer battery should last longer if both are original.
    Considerably quieter and a smoother ride.
    More information on the display.
    Slightly better mileage.
    A little more power.
    Gen 3 looks better than Gen 2 to me.
    Negative:
    I really miss that hidden tray under the middle arm rest.
    Middle arm rest itself doesn't come forward enough to suit me.
    Harder to change the oil. (But not super hard.)

    Specific to the Plug in Prius:
    Positive:
    Combined gas and electricity over the past year (15,542 miles) is $200 less than the same distance vs a 49 mpg hatchback.
     
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  12. dolj

    dolj Senior Member

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    You do, your CM is faulty. The two things that seem to upset the CM when it is faulty are cold and flakey 12 V supply.
    The only warning the car will give you is flash the Master Caution Light (MCL) ( /!\ – big red triangle with ! in the middle) on start up. The MCL is the only warning light that does not light on the self check on start, so it should be very obvious when it flashes. Even so, not many notice it enough to actually think that the car is trying to tell the driver something, that and the fact it turns off so most think, "ah, problem solved."

    You can read the open voltage (Car totally off); the voltage under load (use 10-20 A load), see what it drops to and holds at for 2-5 min; and the voltage with the car in READY. By comparing these, they can be used to ascertain the health of the 12 V battery.
     
  13. Prius Dragster

    Prius Dragster Junior Member

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    Thanks, dolj. It has been colder than a "normal" (is there such a thing?) winter here in VA during December and now into January. Below 0 at night sometimes and teens and 20's during the day, plus wind chills. The day my digital dash went dark was a warm up day in between cold fronts, actually made it in the 60's that particular day. With all of that said, it is now back in the 20's and with what I would consider a "sketchy" 12v battery, I am considering a new one. In typical fashion, the date tabs were not punched out on the battery when it was installed so don't know how old it is. I don't recall seeing the red "!" MCL at start up and did not know to key on it if I saw it, even if it went away. I will be on the lookout for that as well. I will drive it today and pay attention to all lights. - As a side note that may shine some light on how this car was maintained in the past - the low tire pressure light was on in the car when I bought it. I assumed low tire pressure, I can adjust that, not a big deal. Went to a service station air pump when the tires were cold and adjusted all to 35 psi. Light still on. I felt the two tires on the rear were sketchy when I purchased it even though it had a fresh safety inspection sticker on the windshield. Already too long tire story cut very, very short, I ended getting new 4 tires, and when the newer tires were removed to be replaced, it was discovered that both were installed without tire pressure monitoring devices on the valve stems. I am guessing the previous owner did not want to go the added expense of the devices. It goes without saying but I will say it anyway - I could have adjusted air pressure all I wanted, that annoying little light was never going to go out.
     
  14. Prius Dragster

    Prius Dragster Junior Member

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    Combination meter has blacked out again. Temps in the 30's but also rain. Can moisture impact these things? Just feeling around in the dark again. Same problems with turning it off, as in, it would not turn off. Still had power to the main readout information screen and the accessory power outlet on the lower part of the dash was still on. (phone charger adapter still had the blue light on) Finally got the car to turn off but still no speedo/trans indicator/odometer. Two days now. I will disconnect/reconnect the 12v battery, hopefully tomorrow, to see if that does another version of a hard reset. Driving my Tundra for now. Does the ECU retain odometer information if needed? I would assume it does in case I need that information for a replacement CM.....
     
  15. Texas Hybrid Batteries

    Texas Hybrid Batteries Senior Member

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    Unfortunitly miles driven while the combination meter is not functioning don't get logged.

    Matt
     
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  16. Prius Dragster

    Prius Dragster Junior Member

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    A long-winded update follows: Yesterday, I had my combination meter replaced at a local repair shop I trust. Not the local Toyota dealer. I obtained an updated/refurbished CM from Matt at Texas Hybrid Batteries located in Weatherford, TX. Very helpful and knowledgeable with regard to the CM issue. The job looks doable for a backyard mechanic such as myself, but do to weather issues (cold and rainy) and the odometer not working when the CM goes away, I opted to have it done ASAP. I am sure there are those that find the odometer not registering a blessing as they pour untold additional miles on the car (the car drives fine, just no digital readouts straight ahead and the main information screen does not show instant consumption information. No check engine lights or anything like that, Again, all is black) but I don't care for that kind of "record keeping". I am fortunate that the shop I use allowed me to be in the back when the tech was working on it. I even asked questions along the way and they didn't charge me extra! The dismantling process mirrored the Youtube video showing how to replace the CM and the tech just took his time, not forcing anything. He pointed out that many of the plastic parts and clips will become brittle in cold weather, so if doing this without a heated garage or other enclosed facility, the car heater should be run on high long enough to get the plastic parts warm and pliable for bending and tweaking. I sent my old CM back to Texas Hybrid for the core charge and all appears to be good 2 days into it. One of my personal concerns is for the accuracy of the odometer. I find it strange that Toyota designed this vehicle to have a significant part like the odometer memory controlled by only one device; one that as it turns out, craps out fairly often in the generation II's. Anyway, all appears to be good. As a side note, I called the local Toyota dealer to see what they would charge to have this part replaced. The service writer told me it is a 4-hour job @ $115.00 per hour labor rate (My shop charges $80.00 per hour and had it done in just under 2 hours), and the part from Toyota was approximately $400.00 (Texas Hybrid charged less than half this price, but I will leave it to them to convey actual part costs.) Plus, the car had to sit for the 2-3 days at the dealership while waiting for the new CM to be delivered due to the authentication issues with regard to the odometer. Approximately $910.00 was the quote over the phone, barring other issues that may be encountered. I provided my actual mileage (the current reading as it sat in my driveway + the mileage needed to get to my repair facility) to Texas Hybrid when I ordered the replacement CM and they "flash-programmed" the replacement CM to reflect the stated mileage prior to shipping. I was fortunate that the bad CM would come back to life after a day or two for no apparent reason and I had the luxury of being able to park the car while the readout was black. The Inclination Sensor associated with the fuel tank bladder also needs to be reset after the replacement CM is installed. Texas Hybrid provided the step-by-step instructions needed to get this done as well. It took the tech two tries before he got the necessary confirmation readout on the replacement CM. Glad it is done, driving with confidence again.
     
  17. Sam Spade

    Sam Spade Senior Member

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    Excellent post.

    It would be MUCH easier to read if you would hit return occasionally and make some white space (paragraphs). (y)
     
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  18. Prius Dragster

    Prius Dragster Junior Member

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    Noted Sam. Made perfect sense to me as I rambled on, but you are right. As you point out and I was told by many English composition teachers - Assume those reading your story know absolutely nothing about any of the content. Simplify and explain the smallest details and make the story as easy as possible to follow. Otherwise, the reader will lose interest, move on, and your message will not have been delivered.
     
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  19. Sam Spade

    Sam Spade Senior Member

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    ;)
     
  20. Tombukt2

    Tombukt2 Senior Member

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