T-SB-0172-09 Combination Meter - Intermittent Display

[Patrick Wong]

Some of our taxicab driver members first pointed out this problem, since they are logging many more miles on their Prius than normal drivers.
Instrument Panel Problem (with video!!!)

Carolyn of Luscious Garage subsequently provided her theory and analysis regarding its root cause.
http://lusciousgarage.com/index.php/...ead_dashboard/

This TSB acknowledges the problem and indicates an improved combination meter is available.

[dogfriend]

The warranty coverage of 3yrs/36k is a bummer. My impression is that the cars with this problem have been way past the mileage limit.

[philmcneal]

the installation looks easy but i heard combination meter can go for 1k! ai ya i guess i'll have to live with it since its random when it happens lol

thanks guys for the replies

04 prius has almost 220,000 km on it whoo! lol yea it used to be a taxi ... only taxi guys eh

[cwerdna]

Originally Posted by dogfriend

The warranty coverage of 3yrs/36k is a bummer. My impression is that the cars with this problem have been way past the mileage limit.

Yeah, bummer, esp. given that I just noticed the cost that LG cites.

If I'm reading the VIN right (going by the 9 after the #), the TSB applies to ALL vehicles before some point in the 09 model yaer.

I've been to Yazaki's booth each time I've been Tokyo Motor Show... If mine fails, maybe I should gripe to them if I can make it next time...

[wedge40]

My 08 Prius (25Kmiles) has done this twice now on startup in cold weather. Both times after driving for about 20 minutes it came back on and seemed to work just fine.
If it doesn't do it for the service tech, can I use the TSB to get them to fix the problem. Or if I document having the problem now and if fails outside of warrenty will it then be covered?

It really sucks not knowing stuff like speed and the amount of gas I have in the tank.

Wedge

[Patrick Wong]

Suggest you take a good photo when the problem happens so you can prove the problem exists. Also suggest you print the TSB and take with you to the dealer.

[prince101005]

Originally Posted by dogfriend

The warranty coverage of 3yrs/36k is a bummer. My impression is that the cars with this problem have been way past the mileage limit.

I bought the extended warranty for 75kmi and 8.5 years but the tri-fold pamphlet is not clear and waiting on dealership answer (quite busy right now). Anyone know if this problem is covered under the extended warranty?

I've had this happen twice now, both on mornings that were not only cold but that were drastic drops in temperature compared to the day and night previous. Each time I've shut off and re-started a couple of times resulting in the lights coming on. 2008, with 38k miles. Happened last Friday and before that was around 20k miles I believe.

Also, is this problem known to exist in any warmer climates, or only in the cold? I'm moving to Texas soon and may not experience it there. Still want it fixed to stave off any related future problems though. But if the warranty don't cover it than I may wait it out in Texas!

WP

[prince101005]

Update. Contacted the Dealer who said first thing they have to do is try to replicate this. I discussed the TSB with him with this being a recognized problem for my yr Prius and that it has happened only twice so far in 2 years. Now he is going to "talk to his Prius expert" and contact me again tomorrow....what do you think the odds are? ya' me too - I have a camera in the car for next time.

[prince101005]

UPDATE: 12 JUN 2010: Combination Meter replaced by Toyota of Woodbridge, VA.

After taking the car to Toyota Dealership's in Waldorf, MD, Stafford, VA and Woodbridge, VA (in process of moving) I contacted Toyota through their website and they re-contacted me and coordinated an appointment in Woodbridge. There it was replaced and covered 100% through the extended warranty.

[pEEf]

UPDATED: With solution!

There are 2 distinct problems with these boards. The first is a temperature and time sensitive problem. It will generally manifest itself for the first time on a cold day on cars that are getting older. (in other words just out of warranty!) You will power up the car and be greeted to a very dark instrument panel, speedometer, odometer, fuel gauge, PRND display, warning lights, etc. The car will still go to ready and be driveable, but will feel very odd with no lights! Some will pop on later while driving, while some will come on only after a power cycle when warmed up. When you go to shut off the car, one normal press on the power button sometimes will not shut off the car when the display is still black. The solution, until you fix the problem, is to hold the power button down for about 3 seconds.

The second problem manifests itself by the speed / fuel / PRND display doing crazy things or blinking on and off while driving, flashing segments, etc. On rare circumstances the car will need the 3 second power button push to shut down, but generally it will not.

I have now repaired hundreds of these boards with 100% success, both for PriusChatters and locally. I repair both problems on each board, even if they haven't occurred so they are covered for the future. I believe my repaired boards are more reliable than new ones, even the ones with the supposed "fix".

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

Restriction_of_Hazardous_Substances_Directive

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.

Here's the board itself:


If you are under warranty, Toyota will replace this board for you, however the replacement board suffers from the same problem and will eventually fail. If you are not under warranty, the replacement cost starts at around $500, though several people said their "stealers" quoted over $1000!

I am now offering a discounted service for fellow PriusChatters on these Combination Meter boards for a flat fee of $125. (plus shipping)

In the event I somehow cannot repair them, (which has yet to happen) I will not charge you anything for the attempt. I'll also give you a repair warranty for five years, but obviously the warranty doesn't cover damage during shipping or installation, so be careful packing and handling! (I can't repair broken glass!)

As well as costing less and being more reliable, another advantage of repair of your Combination Meter board is your odometer mileage display remains accurate! If you've already replaced the existing one, I can service it for a spare, or for use in another Prius. I can program the correct mileage into it for another car.

Some additional things to consider; you will not have any reverse lights while the CM board is malfunctioning. (or removed) It will also not report vehicle speed to the other vehicle systems. This is why on some cars the Nav doesn't work properly. The rear hatch release has a lockout feature so it doesn't open while you are moving, so the lack of speed indication may prevent the hatch from unlatching when you try to open it. The power ECU also demands a 3 second press on the power button to turn off the Hybrid system if it thinks you might be moving, so this why you must hold it to get the car to turn off. You also will not accumulate any mileage or get any kind of fuel indication or warning, so driving the car will be a bit like gambling.

If you pull (or have pulled) the CM, your car will still run, just like it does when the display goes dark, so the car will still be operable if you wish to use it while the board is in transit. (just be sure to keep that tank topped off!) I can usually turn these around in one business day upon receipt. If you'd like to have it repaired, just send me an email at: P4L at hotmail.com.

I am also working with Luscious Garage in San Francisco on these, so if you are in the SF area, Carolyn will treat you right. She can pull your CM in a few minutes and re-install it once I have repaired it.

If you have basic mechanical skills and a some simple hand tools you can remove it yourself. I only need the actual main board itself as shown in the picture, not the whole cluster, but if you don't wish to take the cluster apart, you can send me the whole thing. The main board is about 9" x 4" so it's small, but needs to be handled and packed well as the VFD display is glass.

[Here] are instructions for removing the CM board, but I know I've seen better written instructions for getting into the dash here in the forums. If someone finds them, I'd love to include a link here. Be sure to disconnect the 12v battery before attempting work!

If you have any questions, or are ready to ship, feel free to send an email to me at P4L at hotmail.com. I accept PayPal for payments and will send you an invoice once your board passes all the tests.