Electric/electronic system, being reset randomly?

Hi,

Last April 2016 I had an impact in the back of my truck (2012 TRD 4x4 v6); nothing serious... bumper had to be changed and bumper support rectified. A day after the impact, traveling in highway ... suddenly all panel lights where on, radio turned off, speedometer , tachometer, etc went a bit crazy... not sure if motor was turned off... situation lasted about 3 or 4 seconds, and then, engine back to normal, radio turned on. Yet... this happened 2 additional times in the lapse of 5 minutes... It was wired. When the bumper was fixed in Toyota dealer, I asked them to review what could happen. As per their scanners, the on board computer reported no actual, no previous error codes; as the impact was not hard on the back of the truck, no electronics / electric components could have provoked that situation (as per their explanation) Everything as per that check, was perfect.

Since that happened (4 months ago), this situation repeated maybe a couple of times, randomly during those 4 months. Today, it happened again: I had to go by highway to a destination that is one hour away. On the way there, same situation; and on the way back, once more... on a random point on the road, all lights on, radio off... came back... and in the laps of around 5 minutes, it happened 3 times. Like if an electrical or computer reset was executed... After this, truck runs normal... no problem at all.

I'm not completely motor turned off as well; sounds are not that clear at about 100, 120 kms an hour with door glasses up... Yet it's very possible as loss of power is evident for the time all lights are on... about 2 or 3 seconds. In one event I was about to pass a slow car in front of me.. And when accelerating... Boom, sudden loss of power and dashboard light on.

What is it about? Maintenances have been ok, on time... and no other type of failures recently.

 

This may sound funny to a lot of folks, but I once read about a situation very similar to yours on a Toyota FJ Cruiser forum. The original poster said that in the end it turned out to be a loose gas cap. Maybe the cap needs replacing as it could be coming loose or have a bad seal?

It's possible the collision jarred something loose on the other end of the truck that a scanner is not going to pick up. You may be dealing with an intermittent electrical problem. I can think of nothing more challenging than this and likely why the dealer in Mexico is walking away from the problem.

I would check the seating of every fuse in the vehicle. There are multiple fuse boxes. One under the hood and at least one under the dash on the drivers side. There may be another. I would test the battery and the alternator and remove + clean the battery cables and posts + ensure all grounds are clean and tight. If this is beyond your ability, I'd find an independent repair shop to do this. I'm not sure how auto repair works in Mexico. Hopefully you have an alternative to the dealer.

 

Replace the starting battery with new.

 

Battery is one year old, Duralast Gold; I'll visit Autozone and have it checked; these batteries are supposed to have a 5 year guarantee. Any way... I'm told the issue I described is very reare in a Tacoma.... not sure if the battery maybe a cause

 

If the battery is not a sealed type, check the electrolyte level in it.

 

Well... got news. I just went to Autozone, I asked them to check the battery... and it was crap; indicator reported "Replace battery"...one year old. So... not sure if it is the root cause of my problem... I'll have to keep checking on highway trips I do ... but by now, I fixed one possible factor. Warranty applied, bad one replaced by a brand new.

So, be careful with Autozone Duralast batteries...even if its "Gold"

 

The impact could have caused the plates in the battery to shift around a bit due to inertia. They are after all made of lead and heavy. A sudden impact even to the back of the truck might have caused one of the cells to short.