G_Body_Man Dork
Nov. 5, 2015 10:03 a.m.

So the transmission in the Sienna I'm taking care of was acting up. It would take ages to kick down, and when the kickdown came, it violently kicked down two gears. So I unplugged the negative battery cable for an hour yesterday. I popped it back on, and went for a drive an hour later. Sure enough, that fixed the issues with the "smart" transmission. Has anyone else done the "total reset" trick and fixed their car?

pointofdeparture PowerDork
Nov. 5, 2015 10:09 a.m.

Works just the same on pretty much anything OBDII with an electronically-controlled transmission that "learns" your driving style. Plugging in a decent code scanner and clearing all the monitors/adaptation values is the easy way.

Brett_Murphy PowerDork
Nov. 5, 2015 10:21 a.m.

A long time ago I had a 1986 Cavalier Z24 that I bought fairly cheaply because the odometer and speedometer in the digital dash would randomly switch from MPH to Km/H. As a broke youngster, my solution was to unplug the battery cable, leave it for 15 minutes with the ignition in the accessory position, then reconnect the cable multiple times until it reset back to MPH.

Furious_E Reader
Nov. 5, 2015 10:24 a.m.

Step one in every troubleshooting guide ever.

1988RedT2 PowerDork
Nov. 5, 2015 10:32 a.m.

Is it best to do that before or after you whack it with a hammer?

jstein77 SuperDork
Nov. 5, 2015 10:43 a.m.
Furious_E wrote: Step one in every Microsoft troubleshooting guide ever.

FTFY

Furious_E Reader
Nov. 5, 2015 10:43 a.m.

In reply to 1988RedT2:

"When all else fails, brute force prevails"

foxtrapper UltimaDork
Nov. 5, 2015 12:14 p.m.

There are some other batteries in various systems that can sometimes keep the charge up enough to negate the disconnected main battery. Which is where turning on the parking lights or such to create an active power drain can help. Yes, the lights will be dead with the main battery off. But having them turned on creates a complete circuit, which will pull down the other little batteries in ECUs and such, even though you won't see a glowing filament.

The Hoff UltraDork
Nov. 5, 2015 12:32 p.m.

I've had quite a few cars (BMWs) lately that required a software update/reset to fix a problem. Just like everything else computerized, sometimes a hard reboot is all it needs.

bigev007
bigev007 Reader
Nov. 5, 2015 12:43 p.m.
pointofdeparture wrote: Works just the same on pretty much anything OBDII with an electronically-controlled transmission that "learns" your driving style. Plugging in a decent code scanner and clearing all the monitors/adaptation values is the easy way.

I've long suspected that's the reason rental cars all shift extra poorly. They're trying to learn completely different styles every couple of days.

GameboyRMH MegaDork
Nov. 5, 2015 12:54 p.m.
foxtrapper wrote: There are some other batteries in various systems that can sometimes keep the charge up enough to negate the disconnected main battery. Which is where turning on the parking lights or such to create an active power drain can help. Yes, the lights will be dead with the main battery off. But having them turned on creates a complete circuit, which will pull down the other little batteries in ECUs and such, even though you won't see a glowing filament.

Not batteries but capacitors. Desktop PCs have so many that if you cut power to one and then press the power button, it'll turn on for a second.

Knurled MegaDork
Nov. 5, 2015 1:08 p.m.
foxtrapper wrote: There are some other batteries in various systems that can sometimes keep the charge up enough to negate the disconnected main battery. Which is where turning on the parking lights or such to create an active power drain can help. Yes, the lights will be dead with the main battery off. But having them turned on creates a complete circuit, which will pull down the other little batteries in ECUs and such, even though you won't see a glowing filament.

The MINI that I serviced two days ago was like this. Despite the battery having been disconnected for 8 hours, the computer still had the fault codes registered and it still had the learned faulty cam position (the chain had jumped time).

The other frustrating thing was that the PCM had to be reset three times before it did a proper VANOS and Valvetronic re-baseline.

flatlander937 Reader
Nov. 5, 2015 1:20 p.m.
1988RedT2 wrote: Is it best to do that before or after you whack it with a hammer?

Percussion adjustment is always step 1

Knurled MegaDork
Nov. 5, 2015 1:34 p.m.

Forgot to point out - increasingly, adaptives and even fault codes are non-volatile. Power loss won't eliminate them, and even clearing the computer with a scan tool won't do it. It has to be reset the "hard way"... driving a properly repaired vehicle.

Wall-e MegaDork
Nov. 5, 2015 6:29 p.m.

Our newest buses are loaded with computers and when we first got them there were a number of issues. On the first run a good pot hole would make the bus think someone tried to fall out one of the doors and it would stop the bus and look the brakes on. To get it to move you would have to open the battery compartment and turn off the kill switch until it reset. Loads of fun when it locks up in a busy intersection during rush hour. Some of them also had to be reflashed when the computers stopped recognizing the engine start button. They still have quite a few quirks and each batch has a different set of problems but at least rebooting them will generally get them to the curb.

ultraclyde UltraDork
Nov. 6, 2015 6:47 a.m.

"Thank you for calling Tech Support, have you tried rebooting it?"

Vigo PowerDork
Nov. 6, 2015 8:29 a.m.

So much superstition, I don't even...

Karl La Follette UltraDork
Nov. 6, 2015 1:58 p.m.

hAD A LADY WITH A A 4 DR IMPALE A 2006 ISH CD was stuck in player tried neg trick did not work . She listening to Xmas CD 24/7

Mike Dork
Nov. 6, 2015 5:49 p.m.

I was stuck in an elevator this week. Someone fixed it and got it to the next floor by power cycling it.

Furious_E Reader
Nov. 6, 2015 6:25 p.m.
Karl La Follette wrote: hAD A LADY WITH A A 4 DR IMPALE A 2006 ISH CD was stuck in player tried neg trick did not work . She listening to Xmas CD 24/7

Are you the guy that writes the Craigslist used car ads?

mndsm MegaDork
Nov. 6, 2015 8:01 p.m.

Works for humans to. Drink plenty of water and get lots of rest is the people.equivalent

Wall-e MegaDork
Nov. 6, 2015 8:19 p.m.
Karl La Follette wrote: hAD A LADY WITH A A 4 DR IMPALE A 2006 ISH CD was stuck in player tried neg trick did not work . She listening to Xmas CD 24/7

I would junk my car if it did that.

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