I have a 2006 H3 that's been in and out of the shop for 2 weeks. The error message: "service stab sys, traction failed, reduced power" came on while driving right before the truck just cut off power completely. I had just enough time to pull over to the side of the highway. The truck runs but idles really rough until the message comes on and the truck dies. So far my mechanic has replaced the O2 Sensor, the MAF, the Throttle Box, the Variable Timing Sensor & the Map Sensor. None of those things has fixed the problem. They're stumped. Anyone have any other ideas? I've asked them to check the PCM, the TCCM, the Encoder Motor, the Stability Control Computer & the Accelerator Accuator Sensors after spending all day here the forum. Does anyone else have any other ideas? Is there something I'm leaving out? Any help at all would be so appreciated! I'm completely frustrated & I miss my H3! Thanks!

 

These issues with the traction are usually the TCCM or Encoder motor, but I'm not sure with the way it's acting....

I had a problem that was fixed 100% by replacing my encoder motor. I got service Stab System, Traction Failed, but never reduced power. In my case the TSB I real suggested replacing the encoder motor. For your case, if I remember correctly, the TSB suggested the TCCM.

Good luck.

 

In my case I started having my traction fail more and more frequently while driving the vehicle. Eventually it would just come on within seconds of starting the vehicle. Before it got to that point some days it would never happen, some days it would happen before I got to the end of my street, and some days it would take 30 minutes. It always went away when turning off the truck completely and opening a door to turn off the accessory until it got to the point of no return.

I'm not sure what causes it, but they said they see it a lot, and Kevin from Rampart Hummer said it was a common issue when he worked at the Hummer dealer to the point where they would keep encoder motors in stock at the dealer.

I've read a few theories of dirty connections, debris entering the motor somehow, etc, but no concrete proof where someone has been able to say "this is why it failed" so that's about all I got tom.

 

I'm betting accelerator pedal assembly. Had the same problem myself. Another member on another forum just had similar experience, they told him the only thing he shouldn't change was acc pedal assem, which is exactly what it turned out to be the problem. You'll be back on the rode by friday.

 

Update on the issue: After replacing everything I listed above, the Intake Manifold Gasket is being replaced. I am hoping this resolves my issue and my 2006 H3 will be fixed.

 

My '07 had the same issues and i tried several similar things that did not work until it was discovered that the spark plugs were basically sitting in water. Sucked all the water out, dried it out and its running like a champ. Sometimes its the simple thing!

 

Any time you suspect a bad intake gasket, spray starting fluid where you suspect the intake leak and see if the engine revs up. It it doesn't you have don't have a leak large enough to cause the problem you're seeing, not even close.

Just a tip for the future before spending more money

 

Here is what you need to know regarding reduced power mode, from exactly what I posted over at CHO, sarcasm included:

"When the Throttle Position Sensor (TB) is not reading the same relative position as Accelerator Pedal Travel Sensor, the computer defaults to reduced power mode because it is not sure how much power the driver is actually calling for.

Solutions: have Scotty find some more dilithium crystals, ...... or, .... replace one of those two sensors to see which is messed up".

That CHO member already had the Throttle Position Sensor at (TB) replaced, my suggestion was correct. There are other scenarios where reduced power mode occurs, but this is the most common with 3s.

First I would look at the Throttle Position Sensor, that is the usual culprit. Many have went bad. If that does not fix the problem, then do the accelerator pedal assembly, which includes the built in Accelerator Pedal Travel Sensor.

Here is you Accelerator Pedal Assembly to try second. Genuine Hummer H3 Accelerator Pedal 2006 - 2009 OEM | eBay

Your StabiliTrack TC Failure can be part of the same problem, but it usually is its own separate issue.


Oh, forgot to ask..... what's a "throttle box?" If you meant Throttle body????, then go with the pedal assembly.

 

If anyone needs an Accelerator Assembly for an H3, I have one that I bought from the dealership and never used. I believe it fits 2006 - 2009 H3's. I can sell it for $40 including shipping.

Email me at pcremodel@hotmail.com

 

Did you ever find out what the problem was? I have the same problem occuring. Mine starting doing this after I had all the brakes replaced, I didn't know if this may have started the problem, If maybe there was something the place did when they changed the brake pads or if It didn't. Service Stab Sys, Traction Failed, Reduced Power but the check engine light comes on as well. But I can turn the motor off for about 15 minutes and it goes off but the check engine light stays on but you can drive it for a while and it will go off. This has happen about 4 times in 2 months and it was just after I had new brake pads put on.