A mess of fault codes and limp mode

[rapidoxidationman]

P0202: Injector Circuit - Cylinder 2
P0300: Random/Multiple Cylinder Misfire Detected
P0302: Cylinder 2 Misfire Detected
P0303: Cylinder 3 Misfire Detected
P0305: Cylinder 5 Misfire Detected
P0308: Cylinder 8 Misfire Detected
P2149: Fuel Injector Group B Supply Voltage Circuit/Open

The truck sounds like the timing is really retarded (clattering like a diesel) and the throttle response MIGHT be about 10%. Turning the truck off for a couple mi utes then turning it back on will allow proper operation for a few minutes then it reverts to limp mode.
Thoughts? It's gonna be a long ride home over Teton Pass...

[Kennedy]

There is not an Edge Juice installed is there?

The LLY has had a lot of issues with the engine wiring harness rubbing/chafing/shorting and it often acts like this. Could be the injector connectors as well.

[rapidoxidationman]

No programmers installed, but I did just last Friday replace the turbo engine coolant return line to the upper radiator hose manifold. I'm thinking there is just a loose connection somewhere, now I just have to find it.

[rapidoxidationman]

Limped it home.
It seems that moving the wires around that go under the A/C bracket resulted in the ability of the engine to perform properly. Now to find out why that is...

[Kennedy]

Over by the alternator/FICM is one of the more common places for a chafe/break in the wires.

[rapidoxidationman]

I'll take a close look at that when I'm freshening the protection of the wires that go under the AC compressor. Last night's research has also pointed me towards taking a close look at the #2 injector harness: It seems that when the tight turn in the cable starts to fail, it can cause the issues I'm seeing. Heading to the driveway in a moment to dig in.

Electrical issues suck. Even with a degree in electronics. :(

[DmaxMaverick]

While it's never a bad idea to protect the bank harnesses, your faults indicate a cylinder "group" failure (2 cylinders from each bank), not a "bank" failure (4 cylinders on one bank). Cylinder group failures suggest something wrong with communication between the PCM and FICM, not after the FICM.

[rapidoxidationman]

While it's never a bad idea to protect the bank harnesses, your faults indicate a cylinder "group" failure (2 cylinders from each bank), not a "bank" failure (4 cylinders on one bank). Cylinder group failures suggest something wrong with communication between the PCM and FICM, not after the FICM.

Copy that.
P2149 indicates an issue with cylinders 2/3/5/8
and will shut down that group.
If I had seen P2146, that would indicate an issue with cylinders 1/4/6/7 and THAT group would have been affected.
Or so I've learned, over the past 24 hours. I rather like my Alldata subscription.
At one point in my trials I saw only two codes, with one of them pointing specifically to cylinder 2 injector power supply issues.
Poked around on that harness plug (literally, poked it with a pick per what is known as the "ice pick mod") to tighten and clean things up. The wires appear intact with no splits or chafing evident. A shot of silicone on the male and female ends and together it went. Tellingly, when I forced that injector to fail by unplugging the harness, the truck did exactly what I hoped and expected: Threw the P2149 code and sounded like it did yesterday. Plugging the harness back in and all was well.

I also pulled the A/C and its mounting bracket to get some fresh wire loom around the exposed wires beneath the bracket. If nothing else, it made me feel good to do so. A few other wires were similarly treated, and it looks a lot healthier in my engine bay because of it. Heat and age had caused a lot of the plastic loom sheathing to crumble.

An evening drive, with copious amounts of throttle employed and plenty of shifting/starting/stopping/ignition cycles revealed a happy engine and zero codes popping up. Time will tell if I actually fixed it, but I'm thinking MAYBE life is good again. At any rate, I'm celebrating with a small glass of Sapling Maple Bourbon from Saxtons Distillery in Vermont. Neat.:cool:

[DmaxMaverick]

I hope it works out.

Neat, of course.