'system shut down' on Mk.3 Yaris.

[Geoff Peace]

On my wifes Mk.3 Yaris, 1.33 litre petrol model. I have noticed that when the ignition is switched off the clock display remains on and the fuel gauge remains stationary. After about twenty minutes or so the clock display goes off and the fuel gauge returns to zero. I presume some system has 'shut down'. If I needed to measure the residual or dark current being drawn by the battery I would need to wait until the system had shut down. Can anyone enlighten me about this please? Also does anyone know the maximum residual battery current for this car please?
Regards Geoff Peace.

[CTScott]

Has it done that since it was new? Perhaps that is a "feature" to still see the clock and fuel level. Those are both functions of the combination meter ECU, which gets both constant power and ignition switched power, so it could easily keep those on after the ignition is off and then do a time out on them.

As for residual battery current, the 2nd gen Yaris shipped with a 45 Ah battery. I can't imagine that Toyota would have changed that for the 3rd gen.

[Geoff Peace]

Thankyou for your reply C.T. Yes it has done this since new and I have encountered a similar thing with a Mazda MX5 Mk.3. So I would think it is normal. From your reply I obviously did not make myself clear regarding my question on residual current. Many terms in the car world seem to be different in the US! I am learning slowly! By residual current, (I think it is called dark current in the US) I mean the maximum allowable current when everything is switched off, the battery negative terminal disconnected and an ammeter connected in series from the battery negative terminal to the negative connector. On many cars it is usually around 20mA. This being the current required to back up the radio memory, clock, ECU etc. I would just like to know the figure for the Mk.3 Yaris if possible. Thankyou.
Regards Geoff Peace.

[CTScott]

Thankyou for your reply C.T. Yes it has done this since new and I have encountered a similar thing with a Mazda MX5 Mk.3. So I would think it is normal. From your reply I obviously did not make myself clear regarding my question on residual current. Many terms in the car world seem to be different in the US! I am learning slowly! By residual current, (I think it is called dark current in the US) I mean the maximum allowable current when everything is switched off, the battery negative terminal disconnected and an ammeter connected in series from the battery negative terminal to the negative connector. On many cars it is usually around 20mA. This being the current required to back up the radio memory, clock, ECU etc. I would just like to know the figure for the Mk.3 Yaris if possible. Thankyou.
Regards Geoff Peace.

Ah, we would call that parasitic (or static) drain. On the MK2 US Yaris it is over 100 mA. I would be very interested in seeing if Toyota improved that with the new ECM on the MK3. With the MK2, not driving the car for 2 to 3 weeks is enough to run the battery down much further than you should.

[Geoff Peace]

Thankyou very much for your prompt reply C.T. i have to say you astound me with a figure of 100mA. This equates to 2.4 amp hours per day, or 16.8 per week. After a fortnight, 33.6 amp hours. No wonder you say it will run the battery down too far. I will check my wife's Mk3 just for curiosity. I would normally be concerned about a drain in excess of 20mA.
Regards Geoff Peace.

[CTScott]

Thankyou very much for your prompt reply C.T. i have to say you astound me with a figure of 100mA. This equates to 2.4 amp hours per day, or 16.8 per week. After a fortnight, 33.6 amp hours. No wonder you say it will run the battery down too far. I will check my wife's Mk3 just for curiosity. I would normally be concerned about a drain in excess of 20mA.
Regards Geoff Peace.

It is the highest drain I have ever seen on a vehicle. My 2011 Toyota Tacoma truck is down in the 20mA range and my 92 Toyota Celica GT is even less.

[Geoff Peace]

Thankyou for your help with this matter C.T.
Regards Geoff Peace.