Injected1

iTrader: (4)

P0300 - Engine Misfire Detected (Old) (History) (Immature)
P0748 - Pressure Control Solenoid Circuit Electrical (History) (Immature)
U1000 - Class 2 Communication Malfunction (History) (Immature)
U1064 - Loss of Communications with DIM (History) (Immature)

Anyone know what this means? this is the DTC off HPTuners.

Injected1

iTrader: (4)

The Misfire and Trans codes are now gone...how ever the communication malfuction is still there along with another one IPC or something to that effect

1slowsilverado

iTrader: (1)

Hpt doesnt clear any codes other than pcm tcm. You are and most everyone here is getting Network codes "underbody" Uxxxx that wont clear. Its normal and no further diag should be wasted. This usually indicates a module that is currently not communicating. For example, if the control module is configured for an option. i.e., OnStar, keyless entry, memory mirrors, or a ton of other things that the vehicle does not have, it may expect to receive a message regarding this missing feature and set these codes.

TigerFan187

iTrader: (1)

Did you happen to download VCM Suite 2.12?

Injected1

iTrader: (4)

actually I was running 2.11, which was a 2.12 beta. Yeah, after doing some research I determined that. Thanks for the info everyone.

Anyone have any ideas why I would be pulling a misfire code randomly every 1k miles ish?

Injected1

iTrader: (4)

Ok, So On my way home from work today I threw another P0300. Now, with that, I am starting to look for what is causing the problem...Random Multiple Misfires two times in two outings is not cool. So I think I am gonna check my MAF and o2 Sensor Connections, maybe look for a melted wire. Then, I am am going to clean the MAF with electrical contact cleaner and see if that helps.

BTW, the Code has only appeared when I am cruising easy in the truck and it seems to run fine when I am running it hard. I am thinking I have a loose o2 connection or a melted wire.

dewmanshu

iTrader: (4)

I am reading that this is common? Such a vague code for something that seems you(the pcm) could label what exactly it is having issues communicating with. At the track yesterday I started the communicating codes. My battery died on me a few days ago...hmmm, my remote start must of caused a definite issue here.

1slowsilverado

iTrader: (1)

Well yes it is common especialy the generic serial codes U1000 or U1255. (generic loss of communication) Witch is basicaly saying there is a problem with a module (Noid) in the Class 2 data line but we're not sure which one. Most common cause would be a moduel looking for a SOH Message that doesnt exist. Now I have a high end scan tool I use that can look for active modules to see if this is false or if further diag is needed. With HPT we cant real do anything except read the codes, Witch some think is cool but there are other functions that are needed to make this useful IMO. Not all Serial codes are BS, They do have a use in diagnostics if you are having issues, But its n ot uncommon for them to set.

1slowsilverado

iTrader: (1)

Could be many things. Do you feel the miss-buck, 35mph steady throttle, But nothing at WOT? Could be as simple as bad wires cracked plug etc. Use the tools you have. In the table display right click, Insert, engine diagnostics, missfire, Lots of stuff in there to log and narrow it down to check the basics on the affected cylnders for a starting point.

1slowsilverado

iTrader: (1)

Also another thing about serial codes, They will set during programing. When the ignition switch is in RUN, each module communicating on the class 2 serial data line sends a state of health (SOH) message every two seconds to ensure that the module is operating properly. When a module stops communicating on the class 2 serial data line, for example if the module loses power or ground, the SOH message it normally sends on the data line every two seconds disappears. Other modules on the class 2 serial data line, which expect to receive that SOH message, detect its absence; those modules in turn set an internal DTC associated with the loss of SOH of the non-communicating module.