I recently bought a new to me 1999 2500. Low miles, 124k. 

 

My issue I'm having is I have codes p1964, no ccd bus and the companion code. I have no wait to start or an intermittent wait to start. What I have found weird is if I unhook my grounds for 5-10 mins then reconnect them the wait to start is immediate for 3-4 key cycles, then goes back to intermittent or not at all. I found this out when I put on new military cable ends, the grounds wouldn't stay tight.

 

Pickup runs fine, doesn't want to start when it's super cold, which makes sense with no wait to start but when it's warm it pops right off and runs great. Also another side note I have had it start and go straight to 1000rpm but shut it off and restart it's fine. I replaced the IAT sensor and coolant sensor just because it's 25 years old, no change. 

 

I'm planning on doing the W-T mod ASAP. But wondering if this means my ECM is toast or I have wiring issues. Just not sure where to start and all the reading is making my head hurt....

 

Thank you for any input!

Edited December 3, 2024Dec 3 by Jespersen79

1 hour ago, Jespersen79 said:

I have no wait to start or an intermittent wait to start.

ECM requires a rebuild before anything else. When the Wait To Start doesn't light up the ECM is NOT booting up. It has internal errors that make it impossible to load up and not start. 

 

Auto Computer Specials.

https://mopar1973man.com/vendor.htm/vendor/auto-computer-specialist-r5/?do=getLastComment&d=7&id=5

 

Edited December 3, 2024Dec 3 by Mopar1973Man

3 minutes ago, Mopar1973Man said:

ECM requires a rebuild before anything else. When the Wait To Start doesn't light up the ECM is NOT booting up. It has internal errors that make it impossible to load up and not start. 

That's what I was afraid of. ACS still the go to? I'm new to this second gen stuff, I've had a 3rd gen for over 10 years and never had any major issues. 

Yup just updated my previous post...

 

Thank you sir! I'll get the W-T mod done before I send the ECM off so I don't fry a new one. At the moment it still starts and runs fine, just doesn't like a 9 degree morning without being plugged in, but who can blame it 😅. 

No problem. Yeah do the W-T ground wire mod, then make sure your alternator passes a AC ripple test.

7 minutes ago, Mopar1973Man said:

then make sure your alternator passes a AC ripple test.

How do I go about that? I've never done it. 

47 minutes ago, Jespersen79 said:

How do I go about that? I've never done it. 

 

Simple remove the alternator walk into a NAPA or similar and tell them you want it benchtested make sure you ask about having it tested for AC ripple. Then if you replace the alternator test the new one the same way before you leave the store.

@Mopar1973Man

I started the W-T mod last night, I just have one question. Where you unhook the grey ground connector on the passenger side that leads to the 4 cables you hook to the gear case, what do you do with the other end? It is y-ed off to another connector that goes towards I assume the PCM. Do I leave that and just reinstall it to the passenger battery ground? Or do I cut that and make it a straight connection to the battery eliminating the grey connector? I can get a picture at lunch if this doesn't make sense. 

The first picture is the one I was talking about. 

 

But found this odd, orange/dark blue wire off the right hand plug is jumped to ground. Why would that be??

 Crappy noise filters for a bad ground and alternator issues.  If it was me I would ditch all that and return to normal stock wiring and fix the real issue of the bad ground with the W-T ground wire mod and then test the alternator. 

4 minutes ago, Mopar1973Man said:

 Crappy noise filters for a bad ground and alternator issues.  If it was me I would ditch all that and return to normal stock wiring and fix the real issue of the bad ground with the W-T ground wire mod and then test the alternator. 

I did the W-T mod, I went with the 150amp breaker and did the fuse on the PCM while I was at it. I replaced the altenator when I got the pickup because it had a bearing noise, I used a Bosch replacement from orileys. I Didn't know anything about the ac noise or ripple test at that time. I went from .041 to .021 after doing the W-T mod. For future reference for anyone that reads this my 99 took a M6 bolt for the case grounds not an M5. I'll pull the Altenator and have it tested when I send the ECM in to get fixed. I got rid of that wire and it hasn't seemed to effect anything one way or the other. 

Keep going you are on the right track.