Check Engine Light + Traction Ctrl Light + 4LO Blinking

Hey PoorRunner Fam

I have a 2011 4WD Limited. I took it in a while ago for a level kit and my traction control light has been on ever since...that's the start of my woes.

Then just this past week my alternator went out and got that replaced by my own mechanic. Following the alternator repair, my check engine light and 4LO came up out of nowhere. Took it to the dealership to check it out and do a brake job, and then they said my catalytic converters are due for replacing but held off.

Got my truck back and the check engine and 4LO were no longer illuminated but the traction control still was. Then all of a sudden this morning the other two were back.

Could really use some advice if anyone could help diagnose. The only scan code that came up was PO420 which is the "Catalyst System Efficiency Below Threshold".

 

Welcome!

The traction control light might be a damaged abs wire from when the leveling kit was done. If you do work carefully when taking the suspension/shock out, will can tear a wire out. Who did the level for you? Did you take it back to them to check?

Regarding the check engine light, the catalytic code that you got is probably what triggered it. It went away because maybe they cleared it when you had them check, but it would come right back if you didnt get it fixed.

The 4LO blinking light…not sure why that would come on, unless you have 4LO selected on the dial? Or maybe it is supposed to come on when the traction control light comes on? Not sure.

How familiar are you with operation of the 4wd system of the limited? I’m not, so it might help to check the manual on how you are supposed to activate the different modes, and then maybe try engaging each mode slowly to see if you can get it to cycle.