How to fix P0135 DTC in Toyota Ipsum 240e 2001. When I disconnect the negative battery terminal and then reconnect the terminal, check engine light goes off when I restart the car. The light will never come on as long as the engine is running. I have run the car for nearly 3 hours it never comes on but when I switch off and restart the car the light will again come on. Please advice what may be the trouble. It gave P0135 trouble code when connected to scanner

remove the battery again and turn ignition on and lights etc any buttons to use up stored power, leave battery off for half hour. then turn everything off, and reconnect the negative terminal on the battery, negative is always off frist to remove battery and negative is always last to be put back on.

To reset the engine malfunction light disconnect the battery negative terminal for 5 Sec or more and then reconnect. Relearn the idle speed control valve. Relearn the windows.
To reset the maintenance light switch on the ignition. Bring the trip meter to A. Switch off the ignition. Press and hold the trip meter button. While pressing the button switch on the ignition and keep pressing it for 10 sec and release.

why not scan it. (next time.)
plug in the scan tool (rented, barrowed, most stores loan them)
and scan it.
easy huh? and free too,, in most USA cities, country not stated, so.....??????

btw new cars , log (DTC log) loss of power.
so newer cars might take, a scan tool to clear it
you got lucky
or as the FSM states, 1 driving cycle with good battery it clears.
RTM.

You should have the error code read from the vehicle's computer (a code scanner is needed for this). If you constantly are disconnecting the battery, some manufacturers program an error code in the computer indicating that the battery has been disconnected within the last XX number of starts. If the code is P1600 or P1630, this is probably your problem. If you're disconnecting the battery for security reasons, either install an aftermarket security/anti-theft system or realize that the check engine light will keep coming on.

I have the same car as yours, a 2003 Toyota Ipsum 240I with a 2AZ-FE engine and had the same Problem. I suggest you change the one closest to the battery (the one with a yellow tape). I prefer the original actually got from yahoo auction.

this an purge exhaust fuel tank , maybe a momentany failure , try to reset, disconnect the negative battery terminal few minutes , reconnect and start engine again

try to reset for a momentany failure, disconnect the negative battery terminal few minutes, then reconnect and start engine

first try to reset the ecu, disconnect the negative battery terminal few minutes, then reconnect start engine and test

try to reset this problem , disconnect the negative battery terminal few minutes and reconnect , start the engine

To turn off the check engine light(CEL),you must clear the diagnostic trouble code (DTC).This can be done with a scan tool.If you do not have a scan tool,you can disconnect the NEGATIVE battery terminal.Do this for a minimum of 20 minutes to clear the keep alive memory (KAM).Reconnect the battery terminal.If the CEL comes back on again,you have not fixed the problem,or another problem has cropped up,requiring a scan tool to see what DTC has set.