Jump to content

  • Welcome To Mopar1973Man.Com LLC

    We are a privately owned support forum for the Dodge Ram Cummins Diesels. All information is free to read for everyone. To interact or ask questions you must have a subscription plan to enable all other features beyond reading. Please go over to the Subscription Page and pick out a plan that fits you best. At any time you wish to cancel the subscription please go back over to the Subscription Page and hit the Cancel button and your subscription will be stopped. All subscriptions are auto-renewing. 

Need help think I may have a bad ecm

Rigtruck92
 Share

Recommended Posts

dripley

dripley

Posted
Posted (edited)
24 minutes ago, Evan said:

Might check out Larry Bs if you just want to buy new cables

I did that's why I built my own. Checked several places and the good ones were quite pricey imho. They appear to good quality of that there is no doubt.

Edited by dripley
  • Like 1
Link to comment
Share on other sites
Rigtruck92

Rigtruck92

Posted
  • Author
Posted

Ok so I checked the iod fuse it was blown changed it and I have dome lights radios back on but I'm still not sure about power to the obdll port. I cleaned the hell out of my batterys they were so corroded when I went to listen them up both the positive terminal clamps broke I'll be getting a whole new set of battery cables. But my truck fired right up and when I bumped the key the lp stayed on like it should. I still dont have a wts light but i ran a test on the cluster and it still didn't come on thinking maybe a burnt bulb. Gona see how it runs tommoro

 

Link to comment
Share on other sites
dripley

dripley

Posted
Posted
2 hours ago, Mopar1973Man said:

 

 

OMG... :doh:

 

Dave you just going to have to toss that Edge Comp in the pile for sale and buy a Quadzilla... 

Later this year I hope. 

3 hours ago, Rigtruck92 said:

Ok so I checked the iod fuse it was blown changed it and I have dome lights radios back on but I'm still not sure about power to the obdll port. I cleaned the hell out of my batterys they were so corroded when I went to listen them up both the positive terminal clamps broke I'll be getting a whole new set of battery cables. But my truck fired right up and when I bumped the key the lp stayed on like it should. I still dont have a wts light but i ran a test on the cluster and it still didn't come on thinking maybe a burnt bulb. Gona see how it runs tommoro

 

Good to hear. Work your way thru it before buying parts, especially expensive ones.

Link to comment
Share on other sites
Rigtruck92

Rigtruck92

Posted
  • Author
Posted

So this morning my wait to start light has came on everytime but its delayed. I think I'll order new battery cables may be having a bad connection problem???

But I'm still having issues with it's starting right. I'm still having to crank on it for a bit

 

Link to comment
Share on other sites
dripley

dripley

Posted
Posted

When the WTS light is delayed the engine will not crank. The ECM turns on the fuel system when it lights. At least everyone I have seen with that issue has experienced that. It is a sign of damaged ECM. But with your cable issues and most likely weak  grounds, I would work thru those issues and pray that helps. Our electrical systems are pretty finicky about that kind of stuff. Next time the light does not light right away wait until it does light and see if fires right off.

Link to comment
Share on other sites
Rigtruck92

Rigtruck92

Posted
  • Author
Posted

Ok well tonight I will be putting new terminals on my cables. Lastnight cleaning them the positives cracked so I'm going to change them all tonight and see if it doesnt help. I appreciate all the help from everyone 

Here is what I'm getting

20180810_191047.jpg

Link to comment
Share on other sites
  • Owner
Mopar1973Man

Mopar1973Man

Posted
  • Owner
Posted
1 hour ago, Rigtruck92 said:

So this morning my wait to start light has came on everytime but its delayed.

 

No. Sorry the delay is caused by memory issues during booting.

 

Our ECM is just like a laptop computer on a smaller scale. It has a CPU, memory, hard drive (PROM) and a BIOS. So basically this all occurs in mere microseconds. When the key is turned on the BIOS tells the CPU to boot the PROM content into RAM and execute the first instruction which is Wait To Start light and grid heater (if the IAT is low enough). That lag your seeing is the bootup process going bad. During the boot up it has a checksum to verify the contents of the code is correct and when the checksum is wrong it reboots again till it matches. The ECM can't do anything till that bootup process completes. 

 

 

What went wrong? Basically, the AC noise from a failed alternator abused the memory and other  components of the ECM this typically stems from people do the lame tin foil mod, or ground wire relocation (old school), or adding noise filters to the PCM for shifting issues (automatic). This give a fail sense of completed repair and the AC noise is just masked from showing. It still beating on the transistors and diodes of the ECM. There was a span of time we all though VP44 where weak and failed because of different reasons. Now knowing the AC noise issue and how to stop it VP44 and ECM failures are rare.

 

How to fix? The only solution is to send the ECM to be rebuilt by one of the rebuilders we have on the list. 

How to prevent this from happening?

 

I would replace the alternator and verify the AC ripple voltage is a passing grade. Like our test of measuring the idle AC voltage at the BATT terminal of the alternator typically lands at 30mV AC which is passing. Full load test could be much higher. Now you can do the W-T ground wire mod. 

 

 

The simple version...

 

  • Like 1
Link to comment
Share on other sites
Rigtruck92

Rigtruck92

Posted
  • Author
Posted

Ok so what your saying is yes my ecm is failing because of the alt is what I'm getting out of this I did check for ac Noise but I'm not sure if I have my multi meter set correct I was getting 30 on the ~

V 200 acv setting is that the correct setting?

20180813_095512.jpg

Link to comment
Share on other sites
  • Owner
Mopar1973Man

Mopar1973Man

Posted
  • Owner
Posted

Sorry but no. Because of the all the flash programming that is required to make it "fit" your truck. You could buy a used ECM and ask around for someone to flash it for you. Way too many version of software and options to just have one available. 

 

I understand your issue but there isn't many solutions to getting around this.

Link to comment
Share on other sites
Dieselfuture

Dieselfuture

Posted
Posted
6 hours ago, Rigtruck92 said:

Ok thanks. Will any of these ecm builders let me buy one and send mine in as a core I use my truck daily for work and cant have it down waiting on shipping?

Link I provided above. Give them your vin number and some money, they will program new ECM to your truck with latest software  ( you can also ask to eneible 3-cylinder cold idle) just so you have it for future. When you receive your new ECM swap them out and send yours in as a core. 

Before you slap new ECM in make sure you're fix all your whiting issues, or it will not be warranted.

Link to comment
Share on other sites
 Share
Go to topic listing

Rate The Author

Please take the time and give the author a 1 to a 5-star rating for the information you have gained from anywhere on the website. All forum threads, articles, etc. If a members post is good information please don't forget to tell them "Thanks" or "Like"

Rate Us On Google

Please take the time and visit our Google Review page and give us a review of our services.

Tip Jar

If Mopar1973Man.Com has helped you with quick and timely information for your repair please consider tossing a tip in the Tip Jar

×
×
  • Create New...