Clock & MPG Screen Random Reset? Gas Gauge?

have them physically remove the battery from the car and do a load test on it to rule it out.

i do not know about the gas gauge

the general rule of thumb is toyota dealers do not like physically testing
the 12 v battery

 

http://www.autoshop101.com/forms/Hybrid13.pdf

that says the dealer can recalibrate the gauge if you have problems with it

 

My '08 just did almost the same thing. This morning, the mileage-per-tank counter reset in the middle of a tank, and this afternoon, the gas gauge dropped from 3 pips missing to empty (fill tank indicator came on.) I filled up right away and only had to put in 3.5 gallons.

I hope this is not a symptom of problems!

 

My guess is that your 12V auxiliary battery is bad. If you have access to a digital voltmeter, perhaps you could measure the battery voltage when the car is IG-OFF and when it is READY.

You can do this either by measuring the voltage from the dedicated jump start terminal in the large relay/fuse box near the driver's side fender to a bare metal point on the body; or else finding the battery in the right-rear corner of the hatch and measuring the voltage at the battery terminals.

When IG-OFF, the voltage should read ~12.6V several hours after the car was last driven. If the voltage is much lower than this, this is evidence that the battery needs to be charged or is bad.

When READY, the voltage should read ~13.8V which shows that the DC to DC converter is working properly.

 

r mann, thx for your message. been having similar problems with my clock and mpg reset, and the car powering on immediately after turning it off. fortunately, no gas gauge problems. Just curious, did the dealer say where exactly the loose pin was located? Do you have any aftermarket modifications like EV Mode?

I've checked the voltage on the 12volt using the onscreen display check and i'm at 14v in ready mode. So, i'm ruling out that its my battery.

 

priususername,

I've been looking for the directions to get the 12V battery voltage up on
the MFD without success.

Could you post how to do this or provide a pointer to where it is?

 

You need to put the MFD in it's maintenance mode. First from accessory mode (to get the battery voltage with no charging current and with a low current load) hold the dashboard INFO button down and flash the parking lights 3 times. Press the on screen menu button and then signals. The Battery voltage should read a little above 12volts.

Now press the POWER button to put a larger current load on the battery. The voltage should drop a little, but stay above 12v.

Now hold the BRAKE down and then press the POWER button to go into READY mode. The voltage should jump to just below 14 volts as the charging system turns on.

Powering down your Prius puts everything back into its normal operation.

JeffD

 

Re: Voltage Display on MFD

JeffD,

Thank you sir. :thumb:

 

A failing 12V battery is the general culprit.

Tom

 

My 2008 Prius is experiencing the exact same problems and they say that I have a faulty ignition switch that is causing my 12V battery to drain. The cost of repair is $304. Is the ignition switch not covered under the powertrain warranty (I have 52k miles on my prius).

Also, I had my Prius in the body shop for almost a month where they most likely left the keys in the car...would this cause any problems to the battery/ignition?

 

There is no ignition switch, so you may want to ask for further details (perhaps a relay is being replaced?)

An electrical issue like that would likely be covered under the 3 year / 36K mile warranty which has expired in your case.

It is certainly likely that the 12V battery had discharged after one month of non-use, regardless of whether the fob was left in the car or not.

 

Thanks. I received a second opinion from another Toyota dealer who says there is an electrical short in the rear passenger side. I was rear ended two months ago on that side and had about $8000 in repairs.

They estimate this repair to cost $480 (mostly for labor).

 

I Have a 2008 GEN II package 5, with a clock that resets intermittently, some times over night sometimes during the day!!! Based on the post I have read it could be the battery or a loose connection in the fuse panel.
Is there a way to check the battery voltage on the 2008 Prius, as the intructions from jdenenberg, did not work for the 2008?

Also does anyone know which fuses it is and where the loose connection might be?


Many thanks to all

Bill

 

You can hook up a decent digital multimeter and check voltage. Unless you've just attempted to charge the 12 volt, and with reasonable ambient temperatures, the voltage should be around 12.6 or higher.

If you have just attempted charging, just drive it around a bit before checking voltage, otherwise your readings will be unrealistically high.

If it's down around 12.3~12.4 that's kind of low. In that case I'd try charging. A decent, low amperage "intelligent" charger, run overnight might do it.

All of the hook-up can be at the fuse box 12 volt battery connection in the engine compartment, check the owners manual for more info.