Car will only go to "ready" state sometimes

I would start with the 12v battery.

 

Those don't seem to exist in my 2001 manual. Would you be able to post a screenshot?

Where did you get the information on what they "might" be about?

-Chap

 

I would start by getting an inexpensive multi-meter and checking the voltage on the 12 V battery.
And then probably replace it.

 

Ah, got 'em. The C1571 and C1572 aren't listed with the regular EMPS DTCs, they're only meaningful in the Input Signal Check test described on pages DI-456 and DI-457. And because they are a test of the input signals from the right and left rear speed sensors, it is normal to have both codes shown if you didn't drive the car 20km/h or faster during the signal check. So for your purposes here, they are probably not indicating any problem at all, and are just a distraction.

On your main health screen, I see a C1202 (low brake fluid), and a C12(glare on the screen), is that C1259? If so, not important, that's just the brake ECU telling you there's an HV ECU code.

Speaking of that HV ECU code, B2799 is an immobilizer malfunction ... pretty much a smoking gun as to why the car won't go READY. You can click the puffy-cloud icon to get the freeze-frame data, which might include a three-digit INF code. 101 indicates the HV ECU gets no signal from the transponder key ECU. According to pages DI-210 to 211, that could be a wiring problem (short or open) in the single black-with-white-stripe wire between the two ECUs (T4, pin 8, to H14, pin 7). If you find such a problem, you just fix it, problem solved.

If you don't, then the focus shifts to diagnosing the immobilizer system itself, referring to pages BE-104 to BE-114. (I did not know this: the transponder ECU can give some codes of its own, just by sending pulses to a dedicated pin on the diagnostic connector, that you can read by connecting a multimeter and counting the needle kicks).

If you refer to the online manual at techinfo.toyota.com, I'm not sure it will have page numbers matching mine (but then, for 2001, it just might; back then, the online version might just have been a scan of the books).

-Chap

 

It does sound like it's OK but........a reading of 12.0 equals half discharged.
In a car like this which does NOT use the 12. V to run a starter motor, it should ALWAYS be well above 12.0; I would start watching it closer at 12.5.

 

Quoting battery voltages without also supplying the conditions/circumstances at the time is just a waste of time.

IF......those readings were made with everything OFF and the doors were kept closed the whole time (ensuring that things stayed OFF)
then your battery is toast. Or possibly there is an abnormally high phantom drain somewhere.
Odds: Battery 90%
Phantom drain 10%

 

When I had a Gen 1, I started it successfully more times than I'd like to admit with the 12 volt battery falling to about 8 volts during start. Some of those times, I had to unplug the ABS pump relays, start the car, then plug them back in. Lower than that, 7 volts or less, I was generally not successful, and would have to charge or swap the battery.

After none of those incidents did my Gen 1 ever report any inaccurate DTCs about anything.

In this thread, going around about whether the battery is at 12.5, 12.25, or 12.05, seems like a distraction from looking into reported immobilizer comm issue.

I am puzzled ... did you look at the specific pages I mentioned, DI-210 to 211 for checking the wiring, and if that's not the culprit, then BE-104 to BE-114 for further diagnosis?

-Chap

 

All the page numbers starting with DI- are in the DIagnostics section, which makes up almost all of Volume 1. Those starting with BE- are in the Body Electrical section, toward the end of Volume 2.

I'm not sure whether the online version is divided into volumes like the paper one, but anyway, all the stuff is under the RM (repair manual) tab once you've signed into techinfo and selected your model and year.

-Chap