2007 Hummer H3 with 148k miles. Last week my turn signal went out. Two days later while driving, the DIC displayed Traction Failed Service Stab Sys and the check engine light came on. I immediately pulled over, shut off the vehicle, restarted and the DIC and check engine light were off.

The next day while driving, the same thing happened. As I was pulling over, the message and check engine light went off, so I continued my drive.

The issue began happening more frequently, and now the check engine light stays on all the time, but the Traction Failed Service Stab Sys is intermittent. However, the DIC now comes on all the time when at idle. Vehicle idles very rough but clears up once I’m driving again.

Had auto parts store scan the vehicle and codes P0204 and P0304 came up which are cylinder 4 misfires. Seems odd that the two can be related or even that the turn signal light is related, but I’ve read on previous threads that anything from brake pedal switch, brake lights, yaw, etc can cause this issue.

Anyone have ideas where to start?

 

Repair the short @ fuel injector #4.

 

Are you still using the crappy azzed Battery Terminal Connectors? If so, hack them off immediately and replace with a quality aftermarket set like Stingers or your favorite brand.

 

I'm onboard with Hummerz and think inspecting the #4 injector wire for a short is a good idea. Doing so takes a bit of time (remove intake baffle, throttle body, serpentine belt, alternator, 9 intake manifold bolts, 3 fuel rail bolts, pull the fuel rail/injectors out, and then open up the fuel injector harness). Gives an opportunity to inspect intake ports and valves as well as replace intake manifold gaskets.

While you have the fuel rail and injectors off, check the function on #4 by "jumping" it with a power and ground wire (with the harness disconnected from the injector, connect a ground to the pin normally connected to the common pink ground wire and the 12V+ to the other pin). This should result in a "click" telling you the injector opens/closes. Then use a multimeter set to the lowest Ohms setting and record the resistance (Ohms) of each injector. Compare the readings between all 5 injectors (should be around 12.5 Ohms).

Here's some photos for your reference:





If you need injectors, I have a set of 5 fully functioning ones (no leaks & good resistance) I just pulled off of my H3. I replaced them with the "late LS truck" injectors.