4lo trac off check engine (2 Viewers)

[TexAZ]

@BillWms01 look for the tundra bypass kits avialable to eliminate the air injection pumps/valves.
it is a poor design/location and common failure on the tundras.
much cheaper to bypass than replace.
i believe @TonyP had the same issue

 

[lrowe_csp]

Did you ever clean your MAF sensor? I had those same codes intermittently on my 49K 2014 and finally got a can of sensor cleaner and cleaned up the MAF. This was 8 months ago and the codes haven't come back since. About a 1 banana 5 minute job. Took longer to buy the cleaner than it did to take the MAF apart and put it back together.

 

[1MAC]

I had this same combination on Monday - CEL constant, TRAC OFF message and 4LO light flashing. It was just a loose gas cap.
Neat trick I learned to drain the remaining charge and reset the codes faster- leave the headlights on when you disconnect the battery. Only had it disconnected a few minutes and my lights were cleared.

 

[KLF]

OK, it's my turn to deal with this. Got in the truck today to run an errand, and lights are on/flashing. Ran the short errand anyway, I could tell the engine was in limp mode. Got home, Carista reports error P033D which as we know is the Bank 2 knock sensor. Tried to reset the code, but it comes right back. I have looked all over as best I can with a strong flashlight and I see no evidence of rodent activity, none of the foam pieces looks chewed on, no piles of nuts or other crap (I've had the problem before with a different vehicle, so I know what to look for). I guess the next step is to remove the intake plenum to look down at the sensors and inspect the harness.

I found the procedure in the FSM for removing the intake, and it says I need to drain the coolant. Is this really necessary? Argh...

 

[Riaz]

OK, it's my turn to deal with this. Got in the truck today to run an errand, and lights are on/flashing. Ran the short errand anyway, I could tell the engine was in limp mode. Got home, Carista reports error P033D which as we know is the Bank 2 knock sensor. Tried to reset the code, but it comes right back. I have looked all over as best I can with a strong flashlight and I see no evidence of rodent activity, none of the foam pieces looks chewed on, no piles of nuts or other crap (I've had the problem before with a different vehicle, so I know what to look for). I guess the next step is to remove the intake plenum to look down at the sensors and inspect the harness.

I found the procedure in the FSM for removing the intake, and it says I need to drain the coolant. Is this really necessary? Argh...

Please let us know how you fix this and thank you and good luck

 

[KLF]

Please let us know how you fix this and thank you and good luck

Will do. Had to put this on hold for the evening for another commitment. Coolant is drained out of the radiator meanwhile. Will start on it tomorrow.

 

[KLF]

So I pulled the intake plenum off this morning... surprise! Not really.

Big wad of some sort of shredded stuffing. I have no idea where that stuff came from, still searching the garage and shed. It's very clean so it's fresh.

Pulled it all out, harness is chewed apart.

More later, after I have parts in hand to put it back together. Might do a separate write-up thread. I can tell you that any dealer that is charging $800-900 for the repair is RIPPING YOU OFF. It's not that hard.

 

[Riaz]

So I pulled the intake plenum off this morning... surprise! Not really.

View attachment 2406526

Big wad of some sort of shredded stuffing. I have no idea where that stuff came from, still searching the garage and shed. It's very clean so it's fresh.

View attachment 2406527

Pulled it all out, harness is chewed apart.

View attachment 2406533

More later, after I have parts in hand to put it back together. Might do a separate write-up thread. I can tell you that any dealer that is charging $800-900 for the repair is RIPPING YOU OFF. It's not that hard.

Thank you very much for sharing.

 

[kangstae30]

Had the CEL, 4LO blinking, and TRAC off warning lights out of nowhere a couple of weeks ago. 2013 Land Cruiser. Turned out to be rat or squirrel damage. Hard to believe as I drive it almost every day.

Aside from some shredded foam around the engine block and a nearly (thank god) chewed through wire harness, there was only a cut wire (1 of 2) to the vacuum switching sensor just under the engine cover. I was able to repair it after some trial and error with connector parts on ebay. (for anyone dealing with this, FYI I ordered 9098011149 from ebay seller "ecu-connect" but it wouldn't fit (but would fit the connection just to the right in photo), and I think 9098011156 is the correct part number. Fortunately I was able to salvage the original connector. If you're doing this I'd order both connectors to be safe).

 

[Weatherman]

I'd recommend a borescope to look under the intake before spending the time removing it. It should be pretty obvious.
Here is a thread with examples of the rodent issue and repair:

DTC P033D: Knock sensor 4, ie: a mouse ate my wiring. How to fix.

Thought I'd do a new thread since it's a specific error that we see occasionally. Just finished repairing mine this evening, so follow along as I show you how to do it, in case it happens to you. Saturday morning, loaded truck up to go to the dump (it's a New Hampshire thing). Hopped in, fired...

forum.ih8mud.com

Rodent nesting under intake