I have a 2005 3.7 Liberty & I have a code for # 4 injector . I have definitely narrowed the problem down to no ground signal from the pcm for that injector . I traced the wire from the injector to the pcm connector , bared a small spot in the wire just outside the pcm connector & there is no ground signal coming out of the pcm on that wire .
Does this definitely condemn the pcm or could something else cause the pcm to not send out a signal for one injector only ? I suppose it’s possible , but I think highly unlikely that the problem could be in the pcm connector itself . I have had it unplugged & the connector & pin both look ok .
I have also been on Jeep forums & I don’t think I’ve already asked this question here but if I have forgive me please .