Same Old Issue - Stabilitrac / Traction Control Off, hard shift, etc

[iam4fsu]

2009 Tahoe LTZ - 198k miles

I was sitting in a driveway with the truck in park. It started idling rough and then the traction control turned off and the stabilitrac turned off. After that, it showed both needed service. Check engine light came on as well. Two days later, it happened again while driving but the engine light was flashing. I had very limited acceleration and the engine was sputtering with rough transmission shifting. I have read every post about this issue and have decided to do the following.

1 - Replace the throttle body - arriving and installing tomorrow (Thursday) thanks to Amazon prime
2 - Clean the Mass Air Flow Sensor - will do this tomorrow (Thursday)
3 - Install Range Technology AFM disabler - will do this Friday

I am doing number three for several reasons. I've had this truck since it was new. It's always used oil and I fought the dealer throughout the entire warranty on the issue. Also, #7 cylinder misfires occasionally when the AFM kicks in. It also often stays in V8 mode when coasting at highway speeds. I have replaced the cylinder coil three times (lifetime warranty) and several months later the code gets thrown again.

I know there are many other things to do including checking cylinder 7 compression, etc. But going to wait on the other items.

I will provide an update over the weekend.

 

[kbuskill]

Did you check the engine codes from the check engine light being on?

If you have a misfire it will turn off traction control and stabilatrac by default to make sure it is not one of those features causing the misfire since those features have the ability to cut power from the engine by reducing engine timing in the event that it detects a wheel spinning to help you regain traction.

When is the last time the plugs and wires were changed?

I recently had this same issue after replacing the plugs and wires on my 08 Suburban LTZ and it was caused by cylinder 1 plug wire coming loose. It kept happening until I took some needle nose pliers and tightened up the metal clip inside the end of the plug wire.

Hope this helps.

 

[iam4fsu]

Did you check the engine codes from the check engine light being on?

If you have a misfire it will turn off traction control and stabilatrac by default to make sure it is not one of those features causing the misfire since those features have the ability to cut power from the engine by reducing engine timing in the event that it detects a wheel spinning to help you regain traction.

When is the last time the plugs and wires were changed?

I recently had this same issue after replacing the plugs and wires on my 08 Suburban LTZ and it was cause by cylinder 1 plug wire coming loose. It kept happening until I took some needle nose pliers and tightened up the metal clip inside the end of the plug wire.

Hope this helps.

I haven't checked the engine codes since the check engine light came on but will over the weekend. The plugs were changed last year. I haven't changed the plug wires. I will check the plug wire connections as well. Thank you for the input!

 

[kbuskill]

No problem... keep us posted about what you find.

Easy way to check the wires = spray bottle with water.

Start the truck and let it run at night and spray the plug wires with the spray bottle of water and look for pretty blue sparks. It should be fairly easy to see in the dark.

 

[iam4fsu]

Wanted to give an update... Replacing the throttle body seems to have fixed my main issue. Crossing my fingers that I just didn't jinx myself. I completed the relearn process after replacing the throttle body and it took about 100 miles before it finally settled down. Once it settled down the rough idle issue came back so I cleaned the MAF sensor. I've only put around 20 miles on it but the idle issue is gone for now. I still haven't done the night time water check on the plug wires but plan to do that tomorrow evening. The AFM disabler part arrived only to be the incorrect part. Come to find out, the part was discontinued and they recycled the part number. Now they only need to update their website. I reordered the AFM disabler from another vendor and it should come tomorrow. Looking forward to all the advantages that will provide. Some more work to do but things are looking good. I will provide another update after putting some more miles on her.

 

[iam4fsu]

Well, I jinxed myself. I started my truck yesterday and the rough idle came back before I even put it in gear. I backed out of the driveway and turned left at a stop sign and the entire issue came back. I am confident that the solution, for me, is to fix the rough idle. I've tried to approach this problem systematically over time so I would know the actual solution. I haven't checked the plug wires with spraying water at night but it's time to do that next. I love my Tahoe but it may be time for a trade in.

 

[kbuskill]

Definitely check the plug wires.

 

[Elmo]

Check the fuel pedal sensor connection. These vehicles are fly by wire. I adjusted pedal height one day and when I started up several hours later I got all those warnings plus the vehicle would not go faster than about 35 mph. I was about to change out the MAF sensor when it dawned on me that I had adjusted the pedals earlier and it might be related. I unplugged the pedal sensor and replugged it and everything worked.

 

[CHASER32]

I have the exact same problem on my 07 Tahoe 2WD. Rough Idle, TC/Stabilitrack Off - Needs Service and just recently a hard shift between 1st and 2nd gear. I'm going to replace the plug wires today and clean the air intake.

A couple of months ago, I had the TC/Stabilitrack Off - Needs Service issue. I brought it to a friend of mine at the local Chevy dealership and he told me to get a turkey baster and remove all the brake fluid from the fill port and then add new fluid. I did and it cleared up the issue immediatly.

 

[CHASER32]

Discovered I had a fouled #7 sparkplug. Changed all the plugs and wires - it was time, changed my brake fluid, and used a can of Sea Foam top engine cleaner and cleared my engine codes. Now she runs smooth as ever.