ECM died. Need help

[Rot Box]

Hi everyone my name is Andrew and I'm brand new to the forum.  I was hoping you could help me with my ECM problem.

 

I have no idea what caused my ECM to fail..  Is this a common issue?  Do I just replace it and cross my fingers or do I need to investigate further?  The truck ran just fine until I pulled in my driveway (luckily) and it died.  I had it checked out and was told the microprocessor fried and the ECM is deemed unrepairable..    

 

Since I can't buy a new one (discontinued) do I buy a used one with no warrantee or do I get a reman unit?  If reman who do you recommend?  I've called a handful of remans companies and every place seems very shady with poor online reviews.  I'm moving my family back to Utah from Florida and I need this truck to get us there safely.  The thought of plugging in a new ECM and having it fail at any time with a big trailer in tow is really bothering me.  Any advise or suggestions would be greatly appreciated.  Thank you for your time,

 

Andrew     

edit:  Also my ECM looks to have been a reman anyway..  not sure if that matters but here’s a pic.  

Edited October 20, 2019 by Rot Box

[JAG1]

Have you been running your lift pump off the ECM? The solution is to have the factory lift pump connector only trigger a relay so the lift pump runs off the batteries then a lift pump cannot fry the ECM. Most all of us have done this modification.

 

Also do you have a fuel pressure gauge to tell what the lift pump is doing for pressure to the VP44? It has to stay above 14 at all times.

 

Our articles section has the list of reputable ECM rebuilders, you should go with them only, as our forum has experience in the past them.

 

Welcome to the forum

[Rot Box]

Jag thanks for the help.  The previous owner wired the lift pump (it’s an Air Dog FP-100) so I’m not sure. That said if I turn my key on the lift pump will run constantly even with the ecu removed..  is there a better way to tell?  

 

Also I’d like to add a fuel pressure gauge asap.  
 

Andrew 

Edited October 20, 2019 by Rot Box

[dripley]

Sounds like it is wired to a key on hot. It should not run at just key on ecept for brief prime. By that I mean less than second. That is with the ECM providing control to relay that gets the power off of the ECM. I am thinking the AD you have should have come with that set up when new. You will have to trace the wires back and see how it is wired in.

 An alternator putting out to much AC voltage can fry the electronics also. Lost mine back in 2006, never knew what fried it.

 

Who checked your ECM out and deemed it unrepairable?

 

 

[Rot Box]

Thanks for the help,
 

Yeah the lift pump runs constantly when the key is on.  The relay is getting keyed on/off power from this wire tap on the blue/white wire on a box under the dash above throttle petal.  Oye who knows haha..  I’m guessing this is not wired correctly.   

I installed a reman Bosch alternator after the ecm died just to be safe.  
 

SIA electronics checked out my ECM.  Said the micro processor is fried.  

 

Andrew 
 

 

 

 

Edited October 20, 2019 by Rot Box

[JAG1]

Rebuilt Alternators are suspect as well. How much A/C ripple is showing on your volt meter with it turned to house type current? Check the article section on how to test for the damaging AC noise throughout the system. Let us know what level its at OK?

[pepsi71ocean]

I believe that the blue/white wire it's the power wire for the central timer. It is on the 99 Dodge that is.

[Rot Box]

Good to know on the alternators.  I’ll read up on and check the ac noise as soon as I can.  

 

Hmm I wonder why they would have wired it into the central timer...  

 

Is it bad to have the lift pump run constantly with key on?  The more I did into this wiring the worse it gets.  Whoever wired it made a nice mess of things.  I’m thinking I’ll order a new harness from air dog and do it right.  
 

Thanks for the help you guys.  

[dripley]

10 hours ago, Rot Box said:

 

 

Is it bad to have the lift pump run constantly with key on?  The more I did into this wiring the worse it gets.  Whoever wired it made a nice mess of things.  I’m thinking I’ll order a new harness from air dog and do it right.  
 

Thanks for the help you guys.  

 

The ECM will shut the pump down as soon as the engine stops running in case of an accident. Handy if you are knocked unconscious. 

[Rot Box]

Ok that makes sense thanks again.  

 

Took awhile to sort out the mess but I finally have the pump wired up properly and with a good relay.  

 

Thinking I’ll pull the trigger on an ecm tomorrow and work on testing out the alternator.  
 

 

[pepsi71ocean]

On 10/21/2019 at 5:57 PM, Rot Box said:

Ok that makes sense thanks again.  

 

Took awhile to sort out the mess but I finally have the pump wired up properly and with a good relay.  

 

Thinking I’ll pull the trigger on an ecm tomorrow and work on testing out the alternator.  
 

 

Go through the article data base and choose a reputable builder. 

 

Then give me an update on the the new reman as time goes on. I have to update that article when I get a chance.

[Rot Box]

On 10/23/2019 at 11:02 AM, pepsi71ocean said:

give me an update on the the new reman as time goes on. I have to update that article when I get a chance.

 

Will do.  I ordered one from ACS Auto Computer Specialists costumer service has been good so far.. 

[Dieselfuture]

You're on the right track, there's a lot to learn still. WT mod, among other things are in order, just be patient and don't hurry things up. Do the important things first to make your move, then take it easy and make every thing else right. 

Good luck 

[JAG1]

13 hours ago, Dieselfuture said:

You're on the right track, there's a lot to learn still. WT mod, among other things are in order, just be patient and don't hurry things up. Do the important things first to make your move, then take it easy and make every thing else right. 

Good luck 

1. Time to move out west and be my neighbor  I will build you your dream shop and then you work on my trucks 

Edited October 26, 2019 by JAG1

[Rot Box]

Just spent the afternoon doing the W-T mod.  Seems pretty straight forward.. assuming I did it correctly.  
 

-Alternator charge cable now connected to pass battery.  
 

-Ground bundle (four black/tan wires + new #6 cable grounded to engine by vp44 and then over to the driver side battery negative.  
 

Sound good?  Thanks again everyone 
 

 

 

 

 

 

 

 

 

Edited October 26, 2019 by Rot Box

[JAG1]

Yes, but because the temperature sensor is on the drivers side battery you need to better balance the system by adding additional paralleling cables between each battery.

Edited October 30, 2019 by JAG1

[Rot Box]

Well the truck fired to life without issue.   I quickly tested the ac ripple and assuming I did it correctly this is what I found... 

 

22.2mV is the highest I’ve seen so far.  Oye is this too much you think? 
 

Also Jag,  when you say paralleling should I run a negative cable from battery to battery?   
 

 

 

[IBMobile]

22.2mV (0.022V) is a good reading.

 

5 hours ago, Rot Box said:

 when you say paralleling should I run a negative cable from battery to battery?   
 

Yes 

[JAG1]

4 hours ago, IBMobile said:

22.2mV (0.022V) is a good reading.

 

Yes 

W-T actually wants to see one more positive cable and two more negative cables battery to battery. This is because the temperature sensor is on the drivers battery making it out of balance.

A major problem arose when my passenger battery had a shorted cell and the temp sensor could not tell it to stop charging. Because I didn't do the crossover cables and it literally shorted out my alternator to the point it was so hot it was smokin'. I have to say it again....it was smoking and it could have burned up the computer.

 

What is very strange is I had W-T's article sent to me from 015point9 with all the pictures because it got lost and sent to me to reestablish and place in the articles section, but now somehow it is gone out of my private messages. I don't understand why it keeps getting deleted off this forum nor how someone can have the hacking power to get into my PMs and do that. It pisses me off because they are gone and cannot place them in the articles section now. W-T wants us to have the article as he wrote it so we all understand everything not just bits and pieces that we remember.

Edited October 30, 2019 by JAG1

[015point9]

12 hours ago, JAG1 said:

 

 

What is very strange is I had W-T's article sent to me from 015point9 with all the pictures because it got lost and sent to me to reestablish and place in the articles section, but now somehow it is gone out of my private messages. I don't understand why it keeps getting deleted off this forum nor how someone can have the hacking power to get into my PMs and do that. It pisses me off because they are gone and cannot place them in the articles section now. W-T wants us to have the article as he wrote it so we all understand everything not just bits and pieces that we remember.

 

It is close to Halloween and spooky things happen?   

Disappearing again?