Need Help! 2012 Tacoma V6 Check Engine Light and Trac Off Light 'Mystery'

Need help from the Tacoma World members, here's why: My 2012 Tacoma V6's Check Engine light and the Trac Off light came on in late October. However, I had no performance / driving issues whatsoever, and my truck seems to run just fine (truck only has 10,000 miles on it).

Took it to the dealer on October 30. Error Codes found were P043E, P045F, P2401, P2402 and P2412 (All Evap Codes).

I had an aftermarket locking gas cap on the truck, and dealer advised me to replace the aftermarket cap with an OEM cap. Dealer reset the Check Engine and Trac Off lights, and I drove the truck 20 miles home.

Didn't start the Tacoma again until an OEM cap was installed. Drove the truck another 75-80 miles and both lights came on again yesterday.

So, before I take it back to the dealer (still under warranty but only until 12/31/18), thought I would reach out to the TW members for your thoughts, before another dealer visit.

 

I had this and, after fighting with it for months, finally got a solution from the dealer. It turned out to be a part that distributes oil. It's a 5 inch rod with holes in it that he showed me. Not sure what it is called, or what part of the engine it came from, but I don't have the problem anymore. Cost about $275 to repair on 2009 DCLB Prerunner.

 

kn61408 thanks for your reply, very much appreciated.

Before you solved the problem, did you get the same Evap Codes like mine that I posted?

I'm not a mechanic, so I don't understand how an oiling system part is related to the Evap system.

Not saying it isn't (I simply don't know).

Thanks,

PDE Tacoma

 

That’s one example.

There’s certainly more possible outcomes than the one he had.

Good luck, welcome to TW.

 

Thanks for the welcome, T4RFTMFW.

What I'm hoping for is that a Toyota Tech expert (Independent tech or dealer) can chime in on this thread.............any techs out there please?

 

I had some of the same codes you had, plus P5440(?), OP. Been a while, so don't remember all the codes.

 

Did you see what codes are present now? If you don't have a scanner, AutoZone or a parts store should be able to scan the truck for you.

 

Going to my local Auto Zone this morning for code check, thanks HAVOC.

Just wondered if others have had this problem, so I could expedite the the process.

 

I'd keep taking it back till they fix it. Before your warranty runs out.

 

That's happened to two Highlanders in my neighborhood in the last year. Both situations had loose/crooked gas cap from a recent fill up.

Reseated the caps, cleared the codes, end of story.

You could give that a try, free and easy.

Otherwise, don't fret, exercise your warranty.

 

357sig and Clearwater Bill, thanks for your replies.

Pretty sure the gas cap is fastened correctly, but I'll re-check.

I'm going back to the dealer, but wondered if anyone else ever has had these five specific error codes all at once.

 

My dash is lit like a Christmas tree. I wouldn't know

 

Sounds like a evap leak problem, take it to the dealer since its under warrenty, they will likely do a smoke test which basically is you close all valves to gas tank and fill it up with smoke and look for where smoke is escaping, please note that you may be expected to leave the vehicle as smoke tests can take a bit of time to look over everything to find the leak.
That said the dealer was right to first say to put a oem cap back on it, otherwise if that was found to be at fault you would be responsible for the diag bill.

 

joeyv141, thanks for your reply, much appreciated.

 

Charcoal canister needs to be replaced

 

Someone with experience diagnosing evap systems will still need to do some testing to find out the problem. The OEM cap was a good first step.

There is a vacuum pump back near the tank/canister that needs to draw vacuum on the system. It then sits back and waits to see if the pressure holds or drops off. If the pressure bleeds down fast it flags a large leak code. If it bleeds down slowly it sets a small leak code. There are a handful of valves that seal the system off from the atmosphere, the intake manifold and some valves that split the system in half (tank half, canister half - common on hondas). If any of these valves are not sealing properly or the pcm command (to close/open) is not making it to the valve, the vacuum will bleed off resulting in a code. Sometimes the vacuum pump itself goes bad and cannot pump up enough vacuum. Vacuum cannot be achieved, resulting in codes.

Not so simple.. a scan tool is required along with a smoke machine, etc

If you want, crawl under the truck and look for any obvious damage to the canister, fuel tank and vapor lines.

 

I had the check eng light and the traction light on some time back and it turned out to be part of some engine harness wire.

 

Stephanlg55, b_r_o and rubenc87, thanks for your input. Because the truck has such low miles (10K) and has never been driven off road (I drive it like an old lady - apologies to any old ladies out there) I don't think there's any canister, tank or vapor line issues, but I'll check.

Thanks, PDE Tacoma

 

The bad side was that I had to make an insurance claim to get it fixed.