TRAC OFF and CIL light illuminated suddenly

Today I was driving and suddenly my TRAC OFF light and CEL (check engine light) came on. My truck started running very rough. Almost the same behavior as when my in tank fuel pump was dying (replaced on a recall).

I was able to nurse my truck home. I had to shut it off twice when it started barely running (no acceleration, bucking and coughing).

Anyone else here have the same warning lights illuminate and same behavior? I have an appointment Monday to get a dealer to look at it, I just need to figure out how to get it there. Very curious as to why this has suddenly manifested in my ‘Taco.

 

2018 TRD Offroad with 178k miles.. I'm having the same problem and the dealership ran a cylinder leak down test and found #1 cylinder was leaking into the intake. They said it needs a full engine replacement at $12,000.00. I declined because it seems only a head problem at best. The other 5 cylinders tested good. I have it at personal mechanic now and he is going to dig deeper into it. I did find this thread and could be the problem also with something getting into the valve.

https://www.tacomaworld.com/threads/2016-tacoma-in-limp-mode-fixed.659782/

 

What? Full engine replacement?

Only 18K on my Tacoma so far. My 'Taco is barely broken in.

 

He said that his dealer quoted him the same price and on the last post in the thread that person said he had a 2017 with 49k and it was his problem also. You just might want to let whoever works on yours know about this because some apparently don't know.

 

Thank you. Holy crap. Read that thread that was referenced. No way to check if that actuator door is intact without removing the plenum?

 

I ordered a cheap OBD2 code reader from Amazon, should have it tomorrow. Am very curious what the CEL is registering. Should've had one of these things in my tool box anyway.

 

Could be anything from that intake plenum actuator to a bad valve/valve seat. Subd for the outcome.

You should have a 6 or 8 year drive train warranty which includes the engine. With your low mileage, I don't see Toyota not taking care of it under warranty.

 

Sorry fellows bout your problem but either you still have the a warranty or an extended . There was another member here with a brand new Tacoma with same issues , although his was covered and I believed got another extension on top of his previous warranty

 

I just realized something. I was out looking briefly at my truck, and I discovered that I did not tighten the gas cap down so it would click. The gas cap was tight but it "clicked" when I checked the general tightness of it. Could it be so simple as the gas cap not clicking when being closed? Fuel/emission/Evap issue? I am waiting on my code reader today from Amazon, I still don't know what code it has registered.

The loss of acceleration/roughness/backfiring of the engine occurs after I have gone down the road for a few miles. Shutting the truck off and waiting a bit, then starting it back up is good for another few miles, then it acts up again. Behaviour just like a bad fuel pump though they replaced it last year during the recall.

 

A loose gas cap will give you a check engine light and could cause the truck to drive a little wonky. Have you driven it since you tightened it down? If it's still wonky after a few miles it isn't the cap. Fingers crossed it is though.

 

Haven't driven it yet. Will take it around the local neighborhood in about an hour. Not sure if it'll do anything but will disconnect the battery for a couple of minutes as well. Need that code reader though, and still am planning to maintain my appt Monday if necessary with the dealer.

 

Theres no mention of performance issues but the OP encountered the same indicators in this thread.

https://www.tacomaworld.com/threads/trac-off-engine-check-gas-cap-loose.467465/

A loose cap could result in low fuel pressure, which could lead to the performance issues you were experiencing. Again, hopefully it's as simple as that.

 

No change. Truck is still in limp mode. Engine running rough. Guess it's on the rollback to the dealer tomorrow.

 

OK, I received the OBD2 code reader and just retrieved the stored codes. They are:

PO352 Ignition coil B Primary Control Circuit Open
PO354 Ignition coil D Primary Control Circuit Open
PO356 Ignition coil F Primary Control Circuit Open

 

Interesting...that's a good thing I guess?

 

This is absolutely bewildering. I just spent about an hour poking around the intake plenum, looking at the coil wires and such. No signs of rodent chewing. So I started my truck and it ran normal. Just took it around BWI at varying speeds and such, for about 7 miles. My truck is running like nothing is wrong with it. At all.

I just erased the codes with my OBD2 scanner, to get rid of the CEL and TRAC OFF trouble lights on the dash display. Maybe this was just some sort of weird fluke? It makes no sense.

I'm going to run my truck a little more tomorrow and see if it's acting normally. May be cancelling the appointment at the dealer. Without codes in the ECU they aren't going to do anything.

 

Ahhh....maybe it was the gas cap after all? And it just took more time to recalibrate? And the error codes you received were a biproduct? Although I'm fairly certain there is a code for the gas cap. I dunno....

 

If it runs well and you've cleared the codes dont waste time at the dealer.

All you'll get is a legit 'can not replicate'

 

Not really sure. I just hope the problem does not come back. The engine was running pretty rough and in limp mode sporadically. From what I've been reading elsewhere, it could be caused by a failing ECM, faulty coil(s), or open/shorted harness and/or poor circuit connections.

With three of them seemingly going tits up for a brief time, my bet is maybe a issue with the harness or ECM itself. I did take off the driver's side kick panel and push on all of the electrical connectors that I could reach going towards the ECM, and the distribution plugs that are also hidden behind there.

 

Oooooh....side note.... "the driver's kick panel." I've heard that's a bear to get back in place.