I left my truck parked for 4 days (almost to the minute), and when I got in it and turned the key, the gauges all pinned then dropped indicating a PCM reset. It cranked a bit slow, but turned over okay. I'm pretty sure these are original batteries (Motorcraft) so I'm sure it's time, but is this a common thing to see when they get weak? The second question is does the PCM know when they're getting weak and shut itself down when left for an extended amount of time? Just curious why it showed a reset...

Joe

 

Check your batteries after a full charge with a Hydrometer.. you can get one from Napa..( Wiggins Auto..) shouuld have them. for about $20.

 

if you replace the batteries, please make sure that you replace both of them... i had some trouble a few months ago.

https://www.ford-trucks.com/forums/5...-no-go-go.html

 

Thanks for the tips. I'll definitely be replacing both, so no problem there.

Anyone have the PCM reset after sitting a couple days? Just wondering what that was about...

 

I don't know about a PCM reset, but all electronics need a good clean source of power or they don't work right.
5 years is about average for battery life.

 

Yeah, it was weird. I'll have a look at them and get some replacements in it. I put batteries in both of my 2000 vehicles around the '05 time frame, so I've been seeing the ~5 year average as well. The GM (wife's Astro) ate three alternators, too. Go figure.

 

If the batts are weak enough yes. If VRef voltage drops during cranking a PCM reset can occur.

 

I hadn't gotten that far yet. All I did was turn the key to light the GPs and the gauges did their thing.

 

Mine cranked VERY slow yesterday (bad batteries) and then stopped cranking....did not do a reset here. All was fine with the new batteries. (Chevy Astros are known for alternator failure, replace it with a new, not rebuilt one) Good luck

 

Not sure why it did that, but it did sit for four days at the airport. On the Astro, the first one I put in was a cheapo, the second I got from a buddy at his cost -- new with a lifetime warranty. Little did I know I would be taking him up on it.....TWICE. I did one better to fix it -- I got the wife a new Mitsubishi Raider Durocross for her B-day...

 

Mine cranked VERY slow yesterday (bad batteries) and then stopped cranking....did not do a reset here. All was fine with the new batteries. (Chevy Astros are known for alternator failure, replace it with a new, not rebuilt one) Good luck

 

sorry for the double-post, hit the send key x2

 

It happens. You can use the "edit" key on the bottom right of your posts instead of re-posting again, for future reference. Ask me how I know...

 

Going through the new beast and found both the batteries to be weak. You guys get 5 years (!!??), we get 2-3 out here. I don't know, something about 120* weather.

I've always had Optima batteries, no problem with using those in my PSD is there? What is the 2nd battery for, the glow plugs?

Would weak batteries cause a "hard start". Doesn't start right up when starter is engaged. It might be normal, I might just need to get used to it.

Thanks Rocky DZL!

 

I guess you could say the second batt is for GPs because after heating them up there might be little left from one batt. Weak batts will cause a hard start but only from a slow crank standpoint. If it cranks nicely, the GPR or GP system needs a look at if it will not fire.