DTC U1026

[silverback]

Well I hooked up the Hypertech today and it tells me I have this code set. I looked up the code (also searched the forum) and it says it's a network type code meaning loss of communications with the ATC. I have around 14.5K miles on the truck so I'm wondering if this is bogus. I'm thinking of clearing the code and running the truck through a diagnostic cycle to see if it comes back. I did have the truck in for service this week and the fuel filter was changed (and I did smell fuel afterward). Anybody have experience with this one?
Thanks,
Ken

[DmaxMaverick]

If you use a scanner and search for codes, often you will find some. Most of them are not "error" codes that need attention, and are a timely issue and part of the OBD system. The computer that controls/monitors the electronics on your truck communicates all the time. If it drops a communication (very common and not harmful), it will set a code that the computer will address and attempt to remedy. In most cases, the code will clear itself quickly, with the causing issue having been resolved. If the issue continues unresolved, it may trigger the SES, and indicate the source of the issue. With few exceptions, if the code doesn't trigger the SES lamp, it is routine and won't interfere with the normal operation of the related systems. The code could have been initiated simply by a "data collision" within the system. This is common and routine. A "data collision" happens when more input data is sent to the computer than the bandwidth allows. The code ensures the computer doesn't "forget" to recheck that system when bandwidth is available.

I suggest doing nothing at this time. Just watch for the code periodically. If it is persistent, it may indicate you have a poor connection at a connector somewhere. If that is the case, you will likely get another code indicating the specific system is effected, and may see an SES. If you have recently had a connector apart, it may help to recheck it and ensure it is properly connected and clean.

[silverback]

DmaxMaverick,
I think you're saying it should clear itself under normal operation (as opposed to me clearing it with the Hypertech). I like that answer. Maybe I'm getting paranoid reading about all the real problems.
Thanks,
Ken

[DmaxMaverick]

I would not suggest clearing any codes that you haven't personally addressed. Like I said, that code is likely part of normal OBD operation. If you clear it, the process that may be involved will have to start all over. Unless the code is being set by a system failure of some sort, it will reset itself. Different codes reset at different rates, depending on the priority assigned to them. Some are automatically reset by ignition key cycles, warm-up cycles, time, or input data (check/recheck) variables.

Paranoid? It's not hard to get that way, especially with too much information. If you look for problems, you will find them, whether they really exist or not.

[silverback]

I'm going to run through this GM driving cycle and see if the thing resets.

A complete driving cycle will perform diagnostics on all monitored systems and can usually be completed in less than fifteen minutes.

Performing a GM OBDII Driving cycle:
1. Cold Start. In order to be classified as a cold start the engine coolant temperature must be below 122