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Need help think I may have a bad ecm

Rigtruck92
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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
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Rigtruck92

Rigtruck92

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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

 

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dripley

dripley

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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.

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Rigtruck92

Rigtruck92

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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

 

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dripley

dripley

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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.

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Rigtruck92

Rigtruck92

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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

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Mopar1973Man

Mopar1973Man

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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...

 

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Rigtruck92

Rigtruck92

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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

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Mopar1973Man

Mopar1973Man

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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.

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Dieselfuture

Dieselfuture

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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.

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