Stalls out when put in gear question? (1 Viewer)

[2001LC]

As a matter of practices I disconnect the battery anytime I'll be unplugging anything electrical. That is, when I'm not being lazy

When doing a general tune-up, which includes cleaning MAF and cleaning/greasing the battery post/terminals. I always start by disconnecting negative terminal from battery, re-connecting negative terminal is last thing I do.

I make sure I've had the battery disconnected for at least 20 minutes just so ECM reset to default. Doing this is key to a good tune up. It insures condition present before tune that I've just spend time clearing/cleaning up are clear out. It only take three normal startup cycles at best for system to relearn and most will never even notice anything while it learns. Not disconnecting battery, has had me chasing my tail wondering why a tune wasn't clear up the "D" vibration. This is the key to a good minor tune up.

On a side note in the 200 series FSM, we're constantly see warning to disconnect battery and wait 90 seconds before unplugging most anything.

 

[abuck99]

Once you unplug the MAF, it has no power. Unhooking the battery removes power from everything. And the ECU has to relearn all of the drive parameters.
The MAF is not as fragile as you think it is. I agree with removing power from it before cleaning. And unplugging it does this.
You can either turn off the main breaker or you can turn off the light switch on the wall before replacing the light bulb. I prefer to turn off the swtich on the wall.

It has nothing to do with protecting MAF. The purpose of battery disconnect is to allow the ecu to relearn from a new baseline after cleaning. It simply helps expedite the process.

 

[Spike555]

It has nothing to do with protecting MAF. The purpose of battery disconnect is to allow the ecu to relearn from a new baseline after cleaning. It simply helps expedite the process.

If that is why you are doing it then I understand.
You could do the same thing just by resetting it with a scanner and not have to reprogram the stereo, HVAC, clock and everything else that gets jacked up when you unhook the battery.

The only time I unhook the battery is when replacing it or the alternator.

 

[Spike555]

As a matter of practices I disconnect the battery anytime I'll be unplugging anything electrical. That is, when I'm not being lazy

When doing a general tune-up, which includes cleaning MAF and cleaning/greasing the battery post/terminals. I always start by disconnecting negative terminal from battery, re-connecting negative terminal is last thing I do.

I make sure I've had the battery disconnected for at least 20 minutes just so ECM reset to default. Doing this is key to a good tune up. It insures condition present before tune that I've just spend time clearing/cleaning up are clear out. It only take three normal startup cycles at best for system to relearn and most will never even notice anything while it learns. Not disconnecting battery, has had me chasing my tail wondering why a tune wasn't clear up the "D" vibration. This is the key to a good minor tune up.

On a side note in the 200 series FSM, we're constantly see warning to disconnect battery and wait 90 seconds before unplugging most anything.

All service manuals say to unhook the battery whenever doing electrical work, they say this for the same reason your toaster says not to use it while taking a bath...lawyers.

3 drive cycles to relearn after unhooking the battery...so 3 drive cycles to relearn if you don't unhook the battery too then right?

 

[2001LC]

All service manuals say to unhook the battery whenever doing electrical work, they say this for the same reason your toaster says not to use it while taking a bath...lawyers.

3 drive cycles to relearn after unhooking the battery...so 3 drive cycles to relearn if you don't unhook the battery too then right?

Your comparing a 12V 100 series to a 120V toaster, lawyers! Let's not go there!

You would think ECM would relearn on it's own, but for some reason it doesn't completely. It's kind of like it learned a bad habit and pass that on to the freshly tuned engine.

I actually started disconnecting the battery to reset the ECM after repeated failed attempts to eliminate the "D" vib. I tried everything and read countless threads where others keep trying and failing. Then I stumbled upon a entries in the tech training manual that said to disconnect battery first then disconnect MAF. I subsequently noticed in the FSM order of assemble when MAF is involved, it always had the order connect MAF then connect battery last. Once I did this "disconnecting battery for 30 minutes", the "D" vib when away. I've lost count of how many 2UZ-fe/times this has work to give me a smother idling engine after a tune up.


I apologies OP getting a bit off topic. Anything new to report on your issue?

 

[LXG8R]

RTH - I am having this issue right now. Hoping the OP has some more info. Right now I am letting it cool down(not that it got hot) @spencer2000LC