Custom programmed PCM and battery replacement
#1
05-20-2013, 08:39 PM
Custom programmed PCM and battery replacement
My battery got weak this morning where I had to put a charger on it for about 15 minutes to juice it enough to get it started. Drove to work that took over 10 miles thinking it would charge up the battery.
8 hours later got off of work, got into the truck and would not start. Got a friend to give me a boost and got it started. However, it would have trouble keeping idle. Very scary that the idling issue can die randomly. it will only die if you give it some gas and let off the gas pedal. Otherwise, the truck will idle if you do not give it any gas. Very bad thing to happen if you are on 635 in Dallas with all the current road construction and there are no shoulders to pull over to get out of traffic.
I made it to Sam's Club and got the battery replaced thinking this should resolve my idling issue as these truck's are so sensitive to electrical needs.
Drove it around the neighborhood to do more shopping. Idling issue is still there, randomly it will die out on me if I let off the gas.
Drove home and played with the idling issue. if I briefly flick the gas pedal to get the engine to rev a little, the engine will drop and almost want to cut out and barely make it back to normal idle. When it dies, and you restart, the ABS and Brake lights will come on for a few seconds and then go away. Not your typical dash light checkout when you initially power on the key.
Took out my SCT tuner to run diagnostics and there are no codes thrown.
As my PCM is customed tuned, I took a guess that the weak battery may have somehow messed up my custom tune. I still have my SCT tuner connected, and said, what the heck, re-programmed my current race 93 octane mode with the same mode.
About a few minutes later after the SCT tuner successfully reprogrammed my PCM with the 93 octane setting, I started up the truck and idling issue is gone. To be sure, I took the truck out for a quick drive, so far so good. Idle fine when foot is let off the gas pedal. All electrical is running to test load the system (a/c, etc..) to put a little load on the engine to make sure the engine will not die on me when I let off the gas pedal.
So to sum it all up, if you are one of those owners that has a custom tuned pcm and suddenly come across idle issues after battery is changed out, just reprogram it again with your tuner and all should be fine.
8 hours later got off of work, got into the truck and would not start. Got a friend to give me a boost and got it started. However, it would have trouble keeping idle. Very scary that the idling issue can die randomly. it will only die if you give it some gas and let off the gas pedal. Otherwise, the truck will idle if you do not give it any gas. Very bad thing to happen if you are on 635 in Dallas with all the current road construction and there are no shoulders to pull over to get out of traffic.
I made it to Sam's Club and got the battery replaced thinking this should resolve my idling issue as these truck's are so sensitive to electrical needs.
Drove it around the neighborhood to do more shopping. Idling issue is still there, randomly it will die out on me if I let off the gas.
Drove home and played with the idling issue. if I briefly flick the gas pedal to get the engine to rev a little, the engine will drop and almost want to cut out and barely make it back to normal idle. When it dies, and you restart, the ABS and Brake lights will come on for a few seconds and then go away. Not your typical dash light checkout when you initially power on the key.
Took out my SCT tuner to run diagnostics and there are no codes thrown.
As my PCM is customed tuned, I took a guess that the weak battery may have somehow messed up my custom tune. I still have my SCT tuner connected, and said, what the heck, re-programmed my current race 93 octane mode with the same mode.
About a few minutes later after the SCT tuner successfully reprogrammed my PCM with the 93 octane setting, I started up the truck and idling issue is gone. To be sure, I took the truck out for a quick drive, so far so good. Idle fine when foot is let off the gas pedal. All electrical is running to test load the system (a/c, etc..) to put a little load on the engine to make sure the engine will not die on me when I let off the gas pedal.
So to sum it all up, if you are one of those owners that has a custom tuned pcm and suddenly come across idle issues after battery is changed out, just reprogram it again with your tuner and all should be fine.
