I will look a little more this afternoon, I found some pinouts for both trucks LB7/LMM. Think I'm going to try on the the 2 main engine harness connectors since it will be the easiest to get to but still need to look for sure.
LLY: EFILive DVT's...broken...?
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I will look a little more this afternoon, I found some pinouts for both trucks LB7/LMM. Think I'm going to try on the the 2 main engine harness connectors since it will be the easiest to get to but still need to look for sure.
In case someone wants to try this with an LLY, here's the ECM pinout:
http://duramaxdiesels.com/forum/showthread.php?t=3978
I think you're right, that will likely be the easiest place to access the injector voltage pulses because it's a pain to get to all the injector connections.
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so you're going to be probing the CONTROL wires from the ECM to the FICM, not the actual high-voltage wires going from the FICM to the injectors.
Scratch that idea, Ben you're right, it wouldn't do anything to probe the comm bus wires.
Ok I've found the FICM connector pinout for an LB7:
http://www.thedieselgarage.com/forums/showthread.php?t=1058
Anyone have a link to the LLY FICM or are the pinouts the same?
Also are the injectors pulsed on the negative (ground) or positive side?
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Update
Well I got around to checking the DVT's today on my 04 LB7, from what I found each cylinder number is the same as what's in the DVT tab at least on the LB7
. I used a scope and verified that the actual cylinder number in the scan tool does in fact turn off the correct injector on the motor. I also verified that scan tool does not turn more than one injector off at a time by clicking each number in the DVT tab on every injector I had the scope on.
I probed the wires at the injector harness's that go into the valve covers, all wiring colors matched up to the diagram except cylinder #1 for some reason. Could someone maybe verify the correct colors I have LtGrn/Red and ORN/BLK. Diagram showed LTGRN/BLK and ORN/BLK witch I think is a typo.
Sorry this took a while I know I said I would look at it a week ago. Someday I will check my LMM but it looks a little harder to get at the connectors.
Well I got around to checking the DVT's today on my 04 LB7, from what I found each cylinder number is the same as what's in the DVT tab at least on the LB7
. I used a scope and verified that the actual cylinder number in the scan tool does in fact turn off the correct injector on the motor. I also verified that scan tool does not turn more than one injector off at a time by clicking each number in the DVT tab on every injector I had the scope on. I probed the wires at the injector harness's that go into the valve covers, all wiring colors matched up to the diagram except cylinder #1 for some reason. Could someone maybe verify the correct colors I have LtGrn/Red and ORN/BLK. Diagram showed LTGRN/BLK and ORN/BLK witch I think is a typo.
Sorry this took a while I know I said I would look at it a week ago. Someday I will check my LMM but it looks a little harder to get at the connectors.
It would be interesting if the injector numbering varied by engine (LB7 vs LLY vs LBZ vs LMM). Clearly something strange was happening when the thread was started and since it was an LLY perhaps the FICM programming was different? I'll be really curious what you find out when you get a chance to do the LMM.
What scope brand/model did you use?
What scope brand/model did you use?
LB7's were not in question as it is a differrent platform for the scantool portion. LLY's from 04.5-05 are the ones in question.
Dammitt ferrm
I know but I don't have a LLY, and I figured someones gotta start somewhere. besides the LB7 was the easiest to get at the wires :angel:
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Well I got around to checking the DVT's today on my 04 LB7, from what I found each cylinder number is the same as what's in the DVT tab at least on the LB7
I probed the wires at the injector harness's that go into the valve covers, all wiring colors matched up to the diagram except cylinder #1 for some reason. Could someone maybe verify the correct colors I have LtGrn/Red and ORN/BLK. Diagram showed LTGRN/BLK and ORN/BLK witch I think is a typo.
Sorry this took a while I know I said I would look at it a week ago. Someday I will check my LMM but it looks a little harder to get at the connectors.
Well at least it proved that it can be tested that way. FWIW I think all engine models should be checked to be sure.
Question though, when it shows the balance rate from say #3 cylinder is at say +11 and you shut off #3 with the DVT does the balance rate change for that cylinder too?
I'm not sure I did not log balance rates or even think to check while turning cylinders off since I was more concerned about the Scope, but I think I did this a while ago. I'm thinking they all go to zero just like when you raise rail pressure way up or touch the gas peddle, thats a simple test though I will check both the trucks I have.
Can you turn off injectors and check balance rates at the same time with a V2?
Maybe I did something wrong, but when I was shutting off injectors it didn't let me switch over to PIDs so I could see them.
I would try another scanner to view them obviously there's no way to hook up more than one device at a time into the OBD port.
I am sureiIf you shut off a cylinder the balance rates across the board would change because the ECM's engine management algorithm would try to make adjustments to smooth out the missing cylinder.
Maybe I did something wrong, but when I was shutting off injectors it didn't let me switch over to PIDs so I could see them.
I would try another scanner to view them obviously there's no way to hook up more than one device at a time into the OBD port.
I am sureiIf you shut off a cylinder the balance rates across the board would change because the ECM's engine management algorithm would try to make adjustments to smooth out the missing cylinder.
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You can set your PID's up and press record, then switch over to your DVT's and do your tests. Go back and replay your log and see what it does when you did your changes. This is how I check balance rates at differrent rail pressures.
Good info thanks.
Just out of curiosity, what can you read from the balance rates by varying rail pressure?
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Maxing the rail pressure out to 160 at an idle will make a leaking injector show up better on the balance rate test. I tested a set once that were all in spec, ramped it up to 160 and one went to a -10.
Good info, I never really bothered because I always logged my
balance without recording everything always wen't to zero on the balance rates and I just said AH F it.
Thanks
balance without recording everything always wen't to zero on the balance rates and I just said AH F it.
Thanks
The DELPHI ECM's can't do balance rates while moving or on the throttle, so you only get one at 0MPH and throttle at 0 as well. Ramping up the rail pressure sure helps to show which ones are dribbling.
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