HELP!! 2006 Sierra v8 5.3 Limp Mode

Ant_46 · May 21, 2019

So I had a check engine light on for awhile didnt think much of it till it thru me into limp mode before work one morning. I did some digging around and ended up replacing my throttle body. Light went away everything was great then a week later it came back on and not long after that it thru me into limp mode. It hasnt done it since. The truck is throwing codes for the TPS, Evap, and a random misfire. Before i go spending money I dont have and throwing random parts at it does anybody have any clue? its been several days since it put me in limp mode but it hasnt come back yet.

Edited May 21, 2019 by Ant_46
missing detail

dtnel78 · May 21, 2019

Test each part properly and go from there. Doing the parts cannon will just waste money on needless parts.

You have to pull the codes as those numbers actually mean things and when you have multiple codes sometimes there's patterns.

Can you pull the codes?

IF you want a faster response go to scannerdanner.com and create a free account and post in the repair help section following the posting rules and be detailed as possible and respectful as well and those forum members will help you resolve it. They know their stuff.

To me it sounds like the throttle body was a band aid and something else is wrong.

Just remember scannerdanner.com . Very smart techs in these forums ajd they're helpful and you'll learn more than you imagine.

Seems as if responses are slow here at times. These guys over there breathe this stuff daily and still can't enough as they love what they Do so it's not a job. A lot love the challenge if you ask me as that's my thing, where's the next challenge!

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riverbanks · May 21, 2019

Check the wiring at tps,a frayed wire, maybe?

sefiroxx · May 21, 2019

Limp mode can be invoked due to:
- ecu receiving way off sensor data
- transmission reporting problems (Ie high heat)
- transmission not receiving signal from ecu (wiring)

ChristianR · May 22, 2019

I recently bought a ‘15 sierra and it threw an engine code. I took it to autozone to get the code read and it came back as a misfire on the 7th cylinder. I took it back to the dealership and they replaced the lifters on that cylinder. It has something to do with the new “Active Fuel Management” mode they have that drops the engine into 4 cylinder mode while you are cruising. After i got it fixed i bought an AFM Disabler that plugs into the OBD2 port and keeps the engine from going into 4 cylinder mode, so i reccomend you go to autozone and get the code read for free and if it says cylinder 7 misfire you will have to replace the lifters. Hope this helped

dtnel78 · May 22, 2019

LEt us know what the end result is

dsr611 · May 22, 2019

14 hours ago, ChristianR said:

I recently bought a ‘15 sierra and it threw an engine code. I took it to autozone to get the code read and it came back as a misfire on the 7th cylinder. I took it back to the dealership and they replaced the lifters on that cylinder. It has something to do with the new “Active Fuel Management” mode they have that drops the engine into 4 cylinder mode while you are cruising. After i got it fixed i bought an AFM Disabler that plugs into the OBD2 port and keeps the engine from going into 4 cylinder mode, so i reccomend you go to autozone and get the code read for free and if it says cylinder 7 misfire you will have to replace the lifters. Hope this helped

No help to OP at all...2006 and 2015 vehicles are totally different beasts. 2006 trucks didn't have AFM

And a misfire on cylinder 7 (or any other cylinder for that matter) doesn't necessarily mean replacing the lifters. It could be the coil pack, bad spark plug, bad plug wires, ECM, fuel-air ratio, etc...any number of things can cause a misfire.

Edited May 22, 2019 by dsr611

ChristianR · May 22, 2019

19 minutes ago, dsr611 said:

No help to OP at all...2006 and 2015 vehicles are totally different beasts. 2006 trucks didn't have AFM

And a misfire on cylinder 7 (or any other cylinder for that matter) doesn't necessarily mean replacing the lifters. It could be the coil pack, bad spark plug, bad plug wires, ECM, fuel-air ratio, etc...any number of things can cause a misfire.

Just saying what fixed my situation. The lifter had gotten messed up from switching between 4cyl and 8cyl so that was what needed replaced