Hummer H3

I was getting off the highway and in the middle of the offramp The check engine light started to flash, truck started running rough, Traction fail and Stab Sys Fail started alternating in that little window below the speedo and the skidding truck idiot light came on. Yikes.

I pulled into the gas station and shut it down. I dug our my OBDII gadget and plugged it in and got 2 codes P0 205 Injector circuit open and P0 305 Misfire cylinder 5 I discovered that I didn't have my tools with me and I was only headed a couple miles up the road so even though I know it's a bad idea, I start the truck and go. Truck runs and goes, but can tell it's running on 4 cyl steering feels stiff like all 4 wheels are engaged. I came up on a hill I figured ZI best get a run for it. When I stomped the gas all the flashing lights on the dash went out, the engine smoothed out and off it went like nothing ever happened. Drove to where I was going and then home about 40 miles with no issues.

Done a lot of reading today and searching of forums and whatnot, but I'm still not sure where to begin looking. I'm thinking PCM/ECM and the bad injector code was computer related but not sure. It's colder than a *****'s heart here in Maine today so I'm taking it to a friends garage tomorrow.

Any suggestions on what to do next? Where to begin? Words of encouragement or a swift kick in the *** to get started? Thanks for your time.

 

Possible electrical issue? How's your battery terminals? Failing injectors and misfires don't fix themselves. Hopefully your friend can get some additional info from perhaps a more comprehensive scanner. Meanwhile suspect electrical connections.

 

check the injector wire harness. they can rub on the intake.

 

Start with the easy things. Check the injector wire harness for frayed wires, put a can of Chevron Techron Concentrate Plus in the tank.
If neither of those, swap the #5 injector with a different injector and see if the P030X code follows the injector you moved or is it still in the #5 cylinder.

 

Still using the crappy stock battery terminals?

 

No. I changed the terminals when I bought it. The previous owner had added a bunch of things and when he sold it to me, pretty much just cut the wires to the stereo, amp, light bar.. whatever else he had put on it so I had a fair amount of cleaning up to do. He had a bunch of things wired directly to the battery it seems, My 1st electronic gremlin was the security system. It would start fine 1st thing but there was about a 50/50 chance of the security lock engaging the 2nd time you start it. Then you had to cycle the key, wait 10 minutes, and then try to start it . I swapped out a new ignition like the internet said, but that didn't fix it..long story short it turned out to be something in the aftermarket remote starter that he installed, I pulled that out and put all the wiring back to oem and it's been fine ever since.

I went through the engine compartment, injector harness looking for something obvious and found nada. I had cleared the codes when I checked them the 1st time, so I figured I'd drive it around and see how it went. Of course, it hasn't replicated the problem. It like nothing ever happened. I get no codes when I check. I've driven all over the place and nothing. It snowed last night here in Maine, so this morning I pounded down the driveway giving it hell and throwing snow up over the hood and nothing. I'm half afraid to just stop looking but I got nothing. I read that if the tires get going different speeds, one of the sensors thinks something is wrong and it will put the truck in limp mode. Has anyone else heard that? I was going a little fast around a pretty sharp corner on a cloverleaf exit. It's my only thought at the moment

 

When a GM vehicle goes into the limp mode for whatever reason just about the worst thing that can happen is that engine power is degraded/removed or if your on the brakes ABS anti-lok is activated neither of these conditions will cause you to loose control. No doubt it will be a pain in the *** but don't be concerned your gonna crash!

Consider starting a log of the codes, what they are, when they happened. Plus note the condition of the drive, were you accelerating, going straight down the road, going around the corner. You get the idea. Perhaps you find a pattern and get it down to a system you can focus your troubleshooting activities on. Electrical gremlins are perhaps some of the most difficult problems to find. Hopefully you have a GM Tech2 at your disposal that you can keep in the H3 to try to catch things as they happen.

Don't give up, you will get there. The fact that you removed an added security system is a good thing. Those damn aftermarket things cause so many problems. Years ago I had a 97 Chevy 2 Door Tahoe that I went nuts trying to get problems out of. The prior owner had 2 different systems installed, one for security and one for remote start. After about 6 months of crazy problems I found a security key under the drivers seat that was having issues making contact and causing faults. One I finally found it and removed it, and all the associated wiring bingo, once it was gone all problems went away! I would have never believed these devices could cause so many issues.

 

It snowed today up here in Maine and it may have given me a clue. I tried to use the 4X4 hi lock and the lights blinked but didn't engage. Tried again. Nothing Tried putting it in neutral and engaging the low lock. also nothing. I swear for a minute then look up "4x4 won't engage" and start reading posts about it. I came across one fella describing what happened when his actuator failed and it sounds suspiciously like what happened to me, "Stab Sys Failed" "Traction Failed" minus the fuel injector code. I haven't ruled out that this is unrelated and there may be two issues. Would be a crazy coincidence for them to happen at the exact same time, but nothing surprises me with this thing.

I haven't tried cleaning the buttons yet, but that's on the list, they seem fine but there is some crud around the edges. The actuator doesn't make any sounds when I try to engage it, and if the video I watched is correct then if it was the plastic fork in the transfer case, the actuator would attempt to shift it just wouldn't engage.

 

the transfercase actuator might just need to be cleaned up or cycled off the transfercase a few times

 

I don't know what you mean by "cycled off"