Hummer H3 3.71 5 Cyl. 2008 (France)
Adapted E85

Hi everybody,
Need some advices...
My default is the following:
I was riding and, having to turn around, I braked normally,
I turned, walk back then walk forward and, at 60KM / H,
the dashboard went illuminating !!
"Engine fault" indicator and also message "Failure traction control
"
I continued 40km to go home ... The engine used to stop few seconds,then going on few seconds etc....
(Apparently in this case working on its 5 cylinders)
As if there were misfires in the arrival of gasoline.
Arrived at home, control of the DTC /
There was P0204 and P0304.

Controlled operation and connections of the 5 Injectors ==> all OK
(Measurement resistances and test trigger with a battery 9V ...)
With the oscillo: no signal (ground) coming from the ECM on injector no.4
While OK on the others!
Remains to be done: test wiring from ECM connector

 

Cyl #4 injector fault and Cyl #4 misfire derived from Cyl #4 injector code.
Use your eyes to diagnose. Inspect the wiring for damage. I've also seen many times, rodents nesting on the engine, chewing wires, causing shorts. GL

 

test goes on: injector continuity 4 OK to ECM .... exit the 2 ECM connectors (take out
the plastic lock Red then raise the unlocking flange of the connector ..). Search for
pinoches corresponding to injectors ... surprise: no. Of pinoches do not correspond to
the doc !!! See photo [img]] jacques.rigaud.pagesperso-orange.fr/Hummer/DCAM0026%20Comments.jpg [/ img].
In all cases OK continuity for all injectors on this connector. The problem comes from
the ECM !!!!
In fact when I started to dismantle everything at the beginning, I realized that the
battery case (+) was slightly loosened and turned slightly ... I did not pay attention
but it could be that mini Breaks of 12V with the vibrations have caused the death of
the driver (in the ECM) of the injector 4. Indeed, when I put the contact without
starting I have a + 12V on all the injectors except the 4 or j I have only 6V (!!! ???) ...
With additionally the fact that I do not have the control (by a 0V) on the injector 4
when the engine is running .... my account is good , It is sure that it is the ECM !!!

 

The picture is here: