How long before a code gets the "H" attached?
Thread Starter
Team Owner
Joined: Apr 2001
Posts: 36,453
Likes: 2
From: Overwhelmed as one would be, placed in my position.... DFW, TX
St. Jude Donor '05
How long before a code gets the "H" attached?
I have been having intermittent engine idle and stumbling problems , so I started paying more attention to the codes section. I cleared all the codes before I drove into work, and when I got here I checked them again. Three codes came up, and all three were: U1064 H. I believe that's a loss of communication with the BCM.
I thought the "H" was odd because I just cleared the codes not twenty minutes (and zero restarts) earlier. WTF?
I thought the "H" was odd because I just cleared the codes not twenty minutes (and zero restarts) earlier. WTF?
Racer
Joined: Mar 2004
Posts: 338
Likes: 0
From: Lancaster Ohio
A history code indicates a problem existed in that module sometime in the last 40 or 50 ignition cycles. When not accompanied by a current code of the same number, it is possible it's evidence of a previous problem. Now solved, that was not removed by clearing codes. More likely is that a history code indicates an intermittent malfunction.
"Intermittent" are the most challenging DTCs. An intermittent may have happened only once, may have happened more than once but is inconsistent in its appearance or may be happening on a regular basis but not at the time the IPC is displaying codes. History codes can also be caused by a current malfunction in a system that is not Operating at the time DTCs are displayed. An example is the rear window defogger, which doesn't operate until the BCM detects engine rpm. For history codes set by a system that does not operate with the key on and engine off, a special diagnostic tool called a "scan tester is necessary to properly diagnose the malfunction
"Intermittent" are the most challenging DTCs. An intermittent may have happened only once, may have happened more than once but is inconsistent in its appearance or may be happening on a regular basis but not at the time the IPC is displaying codes. History codes can also be caused by a current malfunction in a system that is not Operating at the time DTCs are displayed. An example is the rear window defogger, which doesn't operate until the BCM detects engine rpm. For history codes set by a system that does not operate with the key on and engine off, a special diagnostic tool called a "scan tester is necessary to properly diagnose the malfunction
