: A question on diagnostic codes

07-16-05, 10:24 PM
My car has been having trouble starting up when cold. I decided to pull the codes and came up with a few.

PCM P0139 History
PCM P0603 History
ACM B1312 Current
SPM B1147 History
PZM B1983 History

My question is this. Do the "History" codes mean that the car has already had that problem fixed or is it that that problem has not been fixed ? I had the FPR fixed when I bought the car so I don't think it may be that. What can it be now ? I don't take it out much or for that matter start it until lately. Could the battery have lost charge during the 2-4 weeks I rarely used it ? Thanks and sorry for all the questions:hmm:

07-16-05, 10:42 PM
They occur enough to go into history. Current are just that...more important. Have you cleared them and waited to see what returns? I have a lumbar sensor in history that always returns, but it is not that important to me to bug it out yet. The fuel sensor problem that was current was repaired at a dealer just this week and once the problem is repaired and then "cleared" it does not return. Haukap's link, which appears on several threads on the forum is probably the best for explanation of DTC's. Here it is:

OBD II- http://myweb.accessus.net/~090/dtcobd2.html

Good luck.....

07-19-05, 10:42 AM
A code is current when the fault is detected. If the fault is no longer detected it will remain current for three ignition cycles, then go to history where it will remain if not detected again for fifty ingnition cycles at which point it will be cleared.