Computer memory erased

[Traveler74]

1996 4 runner SR-5

I had no idea that when I replaced the battery, that I would erase the memory of the computer. In order to pass the smog test, the tech requires a fully functioning computer with a memory.

So, how much driving and of what type, does it take for the computer re-build a memory? :help:

 

[Skulking]

1996 4 runner SR-5

I had no idea that when I replaced the battery, that I would erase the memory of the computer. In order to pass the smog test, the tech requires a fully functioning computer with a memory.

So, how much driving and of what type, does it take for the computer re-build a memory? :help:

Don't overthink it. Just drive it like you normally would for a week and then take it back in. If it still doesn't show ready, give it another week. There isn't a magic procedure to follow. All of the emissions control systems need to go through cycles in order to show ready for a smog check, so one long drive doing some weird combination of speeds or rpm or something isn't going to do it. If you have an OBD reader, some of them have the ability to check for readiness for smog, so you can keep an eye on it yourself rather than needing to keep going back in to have them check it.

 

[gamefreakgc]

Be sure to mix in both freeway and city driving. It has to re-test the EVAP and catalyst systems by logging miles under certain speeds and timeframes.

 

[dmppdx]

There are also some things that will only reset at certain fuel tank levels so you may have to run the gas level down some before they will reset.

 

[19963.4lsr5]

There are also some things that will only reset at certain fuel tank levels so you may have to run the gas level down some before they will reset.

The evap. If it’s anything like my Saturn the tank must be between 3/4 and 1/4 and above 45f outside.


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[19963.4lsr5]

My long drive to work (32 miles) will set the readiness monitors on my Saturn if it’s not winter time.

The same drive on my 4Runner will set them all, set all but the EVAP, set them all but the CAT.

This last round My EVAP wouldn’t set until it warmed up in late March or early April when I removed the battery and Alt to put install an oil pressure gauge.


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[Traveler74]

Thank you all for the posts.
In my wildest dreams, I never would have imagined that the fuel tank level had anything to do with how a computer resets all of the functions. WOW ! Amazing. :shocked:

 

[TheDurk]

Thank you all for the posts.
In my wildest dreams, I never would have imagined that the fuel tank level had anything to do with how a computer resets all of the functions. WOW ! Amazing. :shocked:

Here is chapter and verse from the horse's mouth as to how this works:

https://f01.justanswer.com/JACUSTOMERram4zxcp/2014-06-01_133438_readiness_monitor_drive_patterns_t-eg02-003.pdf

The On–Board Diagnostic (OBDII) system is designed to monitor the performance of
emission–related components and report any detected abnormalities in the form of
Diagnostic Trouble Codes (DTCs). Since the various components need to be monitored
during different driving conditions, the OBDII system is designed to run separate
monitoring programs called Readiness Monitors. Many state Inspection and
Maintenance (I/M) programs require that vehicles complete their Readiness Monitors
prior to beginning an emissions test.
The current status of the Readiness Monitors can be seen by using the Toyota Diagnostic
Tester with version 9.0 software (or newer), or a generic OBDII Scantool.
To view the Readiness Monitor status using the Toyota Diagnostic Tester, select “Monitor
Status” from the Enhanced OBDII Menu.
A status of “complete” indicates that the necessary conditions have been met to run the
performance tests for the related Readiness Monitor.
The Readiness Monitor will be reset to “incomplete” if:
ECU has lost power (battery or fuse).
DTCs have been cleared.
The conditions for running the Readiness Monitor have not been met.
In the event that any Readiness Monitor shows “incomplete,” follow the appropriate
Readiness Monitor Drive Pattern to change the readiness status to “complete.”
Refer to the Readiness Monitor Drive Pattern Application Table to determine which
drive pattern should be followed.
SECTION P

Get yourself a dang OBDII scantool. They all show readiness monitor status. Must have for even non-mechanics.