I’ve got an 06 6.0 with a crank no start. Originally the truck just shut off while I was driving it didn’t throw any codes wouldn’t start back up even once cold. Just did headgaskets/studs, stand pipes dummy plugs, new hpop, ipr, glow plugs. Went to start the truck and it sounds like it’s missing while cranking, and just threw a code for injector circuit low cylinder 6. I’ll be able to use ForScan tomorrow to check vitals, but wondering if anyone has any advice on what to look for?

 

I've had the same after replacing stand pipes and dummy plugs on my 2005.

I must have nicked one of the o rings on a stand pipe on install and it was in pieces at the bottom of the oil rail.Truck ran great, then just shut off, wouldn't start when it failed.

Low pressure oil was good but wouldn't build any more than 200 psi on HPO and you need 500. You need a way to measure HPO at cranking.

Hope you get it going soon.

 

Circuit low is voltage to the component is lower than it should be, or none at all. You can have more than one issue at a time, but for that, look to the FICM and injector plugs, as well as harness issues. Sometimes, on the injector socket, a pin can get pushed back.

 

You can disconnect the harness at the suspect injector and measure the resistance of each coil to determine if they are electrically open.
Measure between pins 1 and 2 for the open coil and pins 3 and 4 for the close coil.
A typical reading is about 0.8 to 2.0 ohms which is in the middle of the specs.
You can find pin numbers on the face of the connector molded into the plastic and they are very small.
A light and a magnifying glass might help you read them.
If either coil does not meet specification the injector is bad and needs to be replaced.
If the coils test good then you need to test the harness circuits.
If those test good the FICM is suspect (this is the least likely case when you have only ONE injector code, but it does happen).

I have my own test connector, with stripped wires on the end, that I can plug into an injector connector. This provides wires for easy access to the coil testing, instead of struggling to make contact with the pins.

For testing the harness AND injector together: Start at the FICM connector C1388a (the one nearest the firewall). See diagram attached below for C1388a connector pin numbering locations.
Wiring to #6 injector:
Pin #4 (ground) to pin #21 (power) should have 0.8-1 ohms: Open coil
Pin #7 (ground) to pin #22 (power) should have 0.8-1 ohms: Close coil

Please note that up to 8 ohms is considered "in spec", but not a typical reading.

C1388a diagram:
.


Just for an FYI, half the injectors connect to C1388a and the other half to C1388b.
Diagram for C1388b is attached below:

C1388b diagram:
.


The "complete" injector coil testing process (at the injector connector) is:.
Test connector (Pin 1-red, Pin 2-Blue, Pin 3-White, Pin 4-Black):

 

I see you logged in recently enough to see that people provided you with some detailed input...............

How about responding to the advice or updating your progress?

 

Right now I’m a little less concerned over the one injector code because there were no issues previously when it first died on me. Most likely just bent a pin or it’s not plugged in all the way. Anyways I just now changed my icp sensor, and only reading around 7 psi of oil pressure. I’ve now replaced everything in the hpop system and verified low pressure oil. So I don’t understand how I’m not getting any pressure. Considering just taking it to a shop that knows what they’re looking at and not just throwing parts at it anymore.

 

People like bismic know a lot more about these trucks and 6.0 technology than many workshops.
If you want to save money, follow bismic's advice.

 

I have oil at filter but not at pressure switch