kniff_666 Posted July 23, 2012 Share Posted July 23, 2012 Hello there, Just wondering if it really is as easy as disconnecting the battery for about 10mins to reset the ECU? I have read the threads about this but it seems that you then have to leave it idling for a few minutes to "re-configure" itself. I then drive it so it can do this further. Is this correct? And is it really that simple? Will it not mess up something else (e.g. my alarm)? The last and most important question is this ... is it really worth doing this if i am changing/cleaning the O2 sensors? Any help would be much appreciated. Quote Link to comment Share on other sites More sharing options...
stevie_b Posted July 23, 2012 Share Posted July 23, 2012 Yes, disconnect battery for a few minutes. The ECU learns where the idle point should be, so when you reset the ECU it has to re-learn this. No big deal at all: just blip the throttle whilst stationery a couple of times, then drive normally. It shouldn't mess up the alarm. I would turn the alarm off (i.e. unlock the car) before disconnecting the battery just as a precaution. Quote Link to comment Share on other sites More sharing options...
stevie_b Posted July 23, 2012 Share Posted July 23, 2012 PS I would do this if I was changing the O2 sensors. Not sure if it's necessary but it's an easy thing to do, and does no harm. Quote Link to comment Share on other sites More sharing options...
TubbyTwo Posted July 23, 2012 Share Posted July 23, 2012 I didnt reset my ecu when changing the O2 sensor. Might give it a shot. Quote Link to comment Share on other sites More sharing options...
ashbuster Posted July 23, 2012 Share Posted July 23, 2012 why dont you just remove the efi fuse Quote Link to comment Share on other sites More sharing options...
Ian C Posted July 23, 2012 Share Posted July 23, 2012 I see these threads now and again and I swear the duration you're 'supposed' to disconnect the battery gets longer each time. Ten minutes?! Here it is from Toyota: DTCs and freeze-frame data may also be cleared by removing EFI fuse from fuse block, located in engine compartment. DTCs and freeze-frame data may also be cleared by disconnecting negative battery cable. However, other memory functions (clock, radio, alarm, seats, etc.) will be cancelled and must be reset. So pull the EFI fuse out and then put it back in just to clear the codes. Disconnect the battery and reconnect to clear the long term trim tables. No mention of leaving it any time at all As for relearning, they say this: Automatic Transmission *Set parking brake, start engine in "P" or "N" position. Warm-up vehicle to normal operating temperature or until cooling fan cycles. *Allow vehicle to idle for one minute in "N" position. Select "D" and allow engine to idle for one minute. *Accelerate at normal throttle position (20-50%) until vehicle shifts into top gear. *Cruise at light to medium throttle. *Decelerate to a stop, allowing vehicle to downshift, and use brakes normally. *Process may be repeated as necessary. Manual Transmission *Place transmission in Neutral position. *Ensure emergency brake has been set and all accessories are turned off. *Start engine and bring to normal operating temperature. *Allow vehicle to idle in Neutral for one minute. *Initial relearn is complete: process will be completed during normal driving. Personally I just start the car and go. Quote Link to comment Share on other sites More sharing options...
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