2011 2500hd 6.0 misfire

[Aaron P.]

    Well figured out what was causing my issues.(2013 2500Hd 6.0) The truck I am working on is a state hwy truck. This being said it has an auger or spreader on the rear for salt. The feed wire that powers the control unit was tied into (Underhood Panel) fuse #18 which feeds (B1S1 & B2S1 / B+ Ignition Supply) Removed wire now runs perfect on both banks. Where before Bank 1(Cyl#1,3,5,7) was missfiring.   

    Casey I know you probably dont have a wire tapped into your O2 circuit but you may try pulling fuse #18 then apply B+ to the pink wire @ the O2 plug. There is a possibility you have a faulty fuse panel. Hope this helps..

[Aaron P.]

Also want to add I read the voltage at O2 sensor. Reading was battery volyage but somehow was being messed with just enough to effect b1 s1 O2 sensor

[casey.mikl]

19 minutes ago, Aaron P. said:

Also want to add I read the voltage at O2 sensor. Reading was battery volyage but somehow was being messed with just enough to effect b1 s1 O2 sensor

My voltage at the 02 sensors is like 8 volts. I do not get 12v but it is the same at all 4 sensors. I will try to pull that fuse and apply power and see what happens. I’m suspecting the fuse block. There is literally nothing else that it could possibly be. The truck was also from New York and was around salt and such. So it’s a possibility. I’ll try to look at it today. 

[Aaron P.]

1 hour ago, casey.mikl said:

My voltage at the 02 sensors is like 8 volts. I do not get 12v but it is the same at all 4 sensors. I will try to pull that fuse and apply power and see what happens. I’m suspecting the fuse block. There is literally nothing else that it could possibly be. The truck was also from New York and was around salt and such. So it’s a possibility. I’ll try to look at it today. 

There is your issue..you should have battery voltage..apply voltage with jumper wire from battery…bet it clears up if plugs aren’t fouled. I know the 2013 that I am working on fuse 18 feeds upstream O2 sensors and feeds another fuse in which is for downstream O2

[casey.mikl]

3 hours ago, Aaron P. said:

There is your issue..you should have battery voltage..apply voltage with jumper wire from battery…bet it clears up if plugs aren’t fouled. I know the 2013 that I am working on fuse 18 feeds upstream O2 sensors and feeds another fuse in which is for downstream O2

I’m sorry I did check them again and I am getting battery voltage. I’m going to check fuse 18 when I have some extra time. 

[Aaron P.]

Any engine codes? Also do you have access to a good scanner? One you can watch data stream and perform fuel trim reset.  

[casey.mikl]

1 hour ago, Aaron P. said:

Any engine codes? Also do you have access to a good scanner? One you can watch data stream and perform fuel trim reset.  

There are multiple cyl misfire codes and a code for b1s1 02 sensor. I don’t recall the actual code. And I have a snapon solus ultra. 

[shakenfake]

Here is a shot in the dark but have you tried swapping PCMs?

[casey.mikl]

1 hour ago, shakenfake said:

Here is a shot in the dark but have you tried swapping PCMs?

Yes I have the old one and a new one. Swapped them and no change. 

[shakenfake]

Have you pulled your heads? I am wondering now if maybe a lifter is stuck.

[casey.mikl]

36 minutes ago, shakenfake said:

Have you pulled your heads? I am wondering now if maybe a lifter is stuck.

 No I have not. It’s some form of electrical issue. Because when it goes into the loop that uses the 02 sensors. It misfires but when it goes to the default side rhat does not use the sensors it runs fine 

[shakenfake]

So you can see on the scan tool that it is misfiring in closed loop but not misfiring in open loop?

[casey.mikl]

31 minutes ago, shakenfake said:

So you can see on the scan tool that it is misfiring in closed loop but not misfiring in open loop?

Yes but what is weird is when you first start the truck usually it would run in open loop till the truck warms up. It doesn’t, it runs in closed loop, starts to misfire then switches to open loop. 

Edited December 21, 2021 by casey.mikl

[shakenfake]

I wouldn't say that is weird.  When I had my misfire issue it started off in closed and switched to open because it needed a default fuel map.

[lnb]

WELL STILL HAVE NOT FIGURED THIS PROBLEM OUT BUT WORKING ON IT NOW I PULLED THE INTAKE MANIFOLD OFF NOTICED WAY TO MUCH OIL IN INTAKE THERE IS A TSB FOR LEFT VALVE COVER PCV SYSTEM LETTING OIL BYPASS AND GO INTO INTAKE IM WONDERING IF THIS AFFECTS THE AIR FLOW INTO THE INTAKE THAT WOULD NOT BE PICKED UP BY THE MASS AIR FLOW FOR ADJUSTMENT AND CAUSE A LEAN CONDITION ANY THOUGHTS ??