Wont start, turns over

I have a 2001 Dodge Ram 1500, 5.2, they other day it stalled on my way home, had to get it towed, would not start. Replaced the pickup coil, distributor cap and button, TPS. Finally got it started, test drove it ran better than before, later day wouldnt crank, showing no bus on odometer. Started right up after dark and the next morning, then in the afternoon no bus again. Checked all fuses, appear to be good. Any suggestions?? Really confused as to why it will start up in the morning and late at night, but not during the day!

Usually a dying PCM is the culprit (metal box attached to the firewall on the passenger side on the engine bay). Before you shell out the money to buy a reman, make sure all your wiring and grounds are good. Do a google search for Dodge Ram PCM. There are some good step by step wiring testing procedures to be found.

My truck does the same thing. I've tested all my grounds and checked as much wiring as I could. I found if I flex the connector closest to the engine, I could get the truck to start... Lately even that doesn't work. Finally broke down and purchased a reman from A1Cardone for 300 bucks... I will let you know how that works for me this weekend. FYI - Trucks was running great all winter. As soon as it started getting warmer and more humid started acting up again...

From what I've read, no starting combined with "no bus" is almost always an issue with the computer. Try checking the three connectors that go into the computer. If the pins seem dirty at all (not likely but possible, the connectors seal very well), try blasting them with some electrical connector cleaner. Let everything dry then hook them back up. Also check the ECU ground. There's only one wire that takes care of the computer's ground duties and it bolts into the front cowl. Really hard to miss. Try scrubbing the pigtail with some 400-grit sandpaper.

It's kind of a long shot in my opinion. You're probably looking at having to replace the computer but you might get lucky with a connection issue.

I battled with the dreaded "no bus" problem for months before I finally tracked it down to the timer module which on the Rams only handles the intermittent wiper function. Doesn't sound like it makes sense but with this, what the hell is it called, Chrysler Collision Detection wiring setup, pretty much any fault in this line can potentially short the works or just cause some really stupid pain-in-the-ass issues. In my case, the truck started and ran just fine but the gauge cluster would totally cut out at some point while driving. I honestly just took a guess at the timer module after exhausting all other options and got lucky that the problem resided there.

In a case where "no bus" pops up with a "no start" condition, I don't think you're gonna get so lucky.

Good luck whatever you do. All I'm gonna say is ****ing 20-year-old electronics, man.

Would that explain why it will start in the morning and not again til after sunset?

Okay, just went out there at 9 at night, fired right up and ran great! So for some reason it doesnt want to start during the day.

rtarmstrong said:

Would that explain why it will start in the morning and not again til after sunset?

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What's weather like between the two starting periods? I suspect towards sunset it's warmer than in the morning. That would be the only thing I can think of. The heat effecting your truck's PCM. I mean the PCM is a computer after all.

It doesnt want to start during the day when the sun is out, once the sun sets it fires right up. Could it possibly be a bad connection going to the computer?

If the check engine light does NOT come on when you first put the key to ON the ECM is shot.

That self test cycle is a giveaway that the ECM is working.


"Talk is cheap. Whiskey costs money."

Got it at the shop getting a new computer put in today. Helpfully that solves the problem. Thanks for all your answers and help!

So what happened?