To start I have a 99, 2500, Auto, 2x4, 211,000, Lift pump in tank with Relay, 275 HP Bosch Injectors.

 

I am the second owner & got the truck in 2001, IIRC it has 15,000 on it. 

 

To make a long story short, I just finished doing a bunch of things I have been putting off for too long now.

Recently replaced (in order of installation):

Vacuum pump (http://www.fixinrams.com/)

PS Pump (https://www.genosgarage.com/) & Hoses (https://ormebrothers.com/).

Brand new Bosch 275 HP Injectors (Had Edge Jammer Stage 1's & wanted to see the difference)

 

ECM from https://carcomputerexchange.com/    (Lift pump was not turning on reliably & WTS light was acting all wonky)

Fuel Filter housing for 00-02 Cummins https://www.genosgarage.com/product/dodge-ram-cummins-replacement-fuel-filter-cannister-gg-fc98599/360  I was trying to troubleshoot the lift pump driver issue in ECM & Manged to crack the 99 Housing, so $180 later here I am....  

 

VP44 from https://www.bluechipdiesel.com/ (This is the second VP44 I have put onto the truck, the first very early in life, due to dead Lift pump)

 

So here is the deal.  As I mentioned Ive owned this truck pretty much its entire life & have put just about every mile on it.  I had the vacuum pump, PS pump & injectors put into it by a local Dodge shop, because I did not have the time to take care of it.  no issues/worries with that.

 

off & on for the last year or so I was having issues with the ECM turning the lift pump on.  I dug into it a bit & called the folks @ Blue Chip & Doug suggested that I just run the lift pump off of the Wiper circuit (as its hot during "run", but not "start").  while that worked fine (the truck would start & run every time), once of the side effects was that I was getting a P0230 code.  I called Blue Chip  back & he said that is because I did not have a load on the ECM (because the lift pump was disconnected) & that I should just "stick a fan on it to blow across the Inj pump" so that the ECM would see the load.  I didn't like that idea, so I wired another relay on that output (the exact same relay that I am using for the lift pump) & much to my surprise that did not resolve the issue. 

 

I did a bit of research & called 6 or 7 ECM sources & found that car computer exchange seemed to be knowledgeable about the Cummins specific issues & had a good answer to each of my questions (Im a Manufacturing Engineer for a company that produces devices that measure air pollution).  They were waiting on cores & said if I return mine I would get it quicker than if I waited to order one & then send my core back later.  So I did that.

 

I replaced the ECM & fuel filter housing @ one time & rewired the Lift pump back to the ECM where it should be.  every few years I check all of my grounds to make sure that there is no corrosion (like we get any weather in San Diego, right...............) & that everything looks ok.  I purged all of the air out & fired up the truck & it fired up after a little cranking.  HOWEVER......... the CEL came back on again. I hooked up the scan tool, cleared it & fired it back up again.  no more CEL.  Yes I did something stupid............. I did not read the code(s) I just cleared it/them. 

 

I replaced the Injection pump & when I went to fire it up, I found the batteries were on their way out (slow cranking & no fire).  they were 5 years old so I replaced them.  Hit the key with the new batteries & it cranked over great & fired right up.  HOWEVER the CEL is back on again. 

 

I broke out the $10 China Freight scanner & it came back with "there are no codes" (yes the CEL is on)  This is not the first time this has happened.  So I broke out the OTC Genisys, & the freaken thing wont talk with the stupid truck.  This is not the first time this has happened over the last 8 or 9 years.  Ive had this issue off & on for a while.  Ive not cared because the truck has worked fine & not had any CEL's so why would I care (paying for that now..............). 

Here is where it gets weird.  If I use the HF scanner & force it to clear the CEL it will do it.  if I ask the OTC to clear the CEL, it will not.  neither of which will "get data from the truck".   the CEL comes back on just about every time I try to start the truck.  Ive cleared & started it 20 or 25 times since I replaced the Inj pump & most of the time the CEL comes back on.  I have tried a few things. like checking connections & Grounds & other such things to figure it out, clear the CEL & fired it up & it comes back on........

 

MORE....................

 

So........ the questions.......

I have a factory manual & have dug into the schematics & see that there appear to be 2 Comm buses.  once is the CCD & the other is the SCI. 

I have read a bunch of stuff on this site as well other places, but am kind of confused about how this works & what does what. 

 

as much as anything Im trying to learn with these questions, not to just fix my problem, so bear with me. 

 

I get that the CCD talks between the ECM, Timer, Dash, PCM, etc to transfer information from one place to the next.  it is also present on the ALDL so I would assume that a "scanner" can talk on the buss as well to get data out. 

 

It appears that the ECM & PCM are connected to the ALDL on pins 6, 7 & 14.  Its interesting to me that there is a single transmit line shared between both computers, but they each have separate receive lines. 

 

SO............... When I hook up my scan tool cheap *** scan tool what is it talking with?  the ECM?  through the SCI lines or the CCD? 

 When Im using my OTC & turning on & off the AC Clutch, Trans Solenoids, lift pump, etc.  what buss is it using? 

When there is a code that the trans is not working correctly, where is that coming from?  is the scan tool talking with the ECM via the SCI & its getting the codes from the PCM through the CCD?  How the heck does this work.........

 

Shoot........... I didn't want everything in one HUGE post............

So, Specifically to this problem.

How do I go about troubleshooting my communication issue?  I took the OTC & plugged it into my wifes Mercury & it allows me to see everything & do everything, its working correctly. 

I have had issues with the Truck talking to scanners before, but Ive also had it work just fine & allow me to turn on the trans stuff & to datalog ECM & PCM stuff & watch the APPS voltage go up & down & everything you would think it should be able to do. so I know that it has worked before. 

IMO, I need to get the scanner working before I can figure out why the CEL is on.  I suppose I could assume that its the same P0230 code, but I dont want to assume anything........... 

thanks folks.
Bob

 

Edited October 16, 20177 yr by Bobalos

however I think the likely issue is just a shotty rebuild of the ecm.  AC noise shouldn't fry the ecm that fast.  

 

I would replace the alternator if you are seeing a ton of ac noise for good measure, but I dont think it is what is causing the issue, I think that the issue is the source of the rebuilt ecm.  

 

rebuilt ecms are a crap shoot.

Any suggestions.on where to go?  I'm not impressed with this company.

 

The AC noise is fine as long as the grid heaters are.not on....  I will unplug them to test. 

 

 

The blips I saw in your video seem very short compared to how mine react. Mine are on for a few seconds them off and the process starts over. Not sure what that means it just looks different the mine behaves.

 

I have to agree with me on both of the above. AC voltage will kill the electronics over time. I would suspect the ECM also. Been there done that and have a very nice ECM paper to remind me of it. I would check with Cummins and see what they can do for you with an ECM. That is where I would go first. They might be to pricey up front but I wish I had gone there first. There is no telling how much I spent getting my cheap one.

 

You might check this out. Someone else going thru the same thing.

The Go ECM he mentions Is worth checking out. I have no experience with them but an old member here mentioned a good while back. @cajflynn. Stumbled across the post while googling one day and he mentioned them with another co that he had success with. He got 1.3 million miles out of his 2nd gen before a wreck took out. Hauled boats boats with it for a living. All and all though I have to agree on the crap shoot part of ECM rebuilders.

8 hours ago, Bobalos said:

The AC noise is fine as long as the grid heaters are.not on....  I will unplug them to test. 

 

 

Then to double check remove the alternator and have it bench tested. That will double verify. 

There is a Alt/Start company down the road from me that I used to use all the time when I was in college & the old guy that worked there was very good & would help just about anyone out. 

 

I will swing by with the Alt & see if they can bench test it.  its been 20 years, who knows if they are even owned by the same guy. 

 

Im still unsure where to go for the ECM.  I guess I can try Cummins on Monday, there is a local Cummins place here.  I wonder where they get them rebuilt.......

 

thanks

Bob

 

Be warned all ECM today are remanufactured there is no longer any new ECMs...

Yep.

Mopar1973Man (I think your name is Mike, but dont remember exactly.......).

 

I seem to recall in one of your other posts you mentioned that you dont have your grid heaters plugged in most of the time.  How do you get around not getting codes?  or do you get them & just ignore them??? 

 

I was just playing with mine & found that when I unplugged the relays I got a P0380, Po382 & P1291, which I think are all grid heater related.

 

My OTC will not connect to the truck, but my $5 China Freight one will both get the codes & clear them.  go figure.............. 

 

I started the truck up w/o the grid heater relays plugged in & the AC noise went to 12-16 mVAC (slowing moving around) & the DC was 14.11 & rock solid. 

 

I found that the Hot side on the forward relay was a VERY bad connection.  it looks like it was hit or something & the connection was opened up enough to make it sloppy on the post on the relay. 

 

I cleaned all 4 connections up & tightened up that one connector & wouldn't you know it, it seems pretty happy now.  I read both the AC noise & DC voltage & it seems MUCH better.  in fact its more stable than when I had the Grid relays disconnected.  Im getting 12 to 13 mVAC & 14.1 VDC VERY solid........... 

 

the WTS light is still inconsistent, but I was doing a bunch of starts & stops & setting DTC's & clearing them & whatnot, so Im going to give it an hour & try it again & see if its happy or if its just screwing with me again...........  LOL. 

 

Im hesitant to call this thing fixed, but.......... it sure does seem a lot more happy.......

 

Bob

 

6 hours ago, Mopar1973Man said:

Be warned all ECM today are remanufactured there is no longer any new ECMs...

Isn't there anyone that might be building an aftermarket ECM?

 

Is there a problem stemming from the fact that information required to build one, is strictly proprietary information?

Edited October 29, 20177 yr by JAG1

In my case that would not be of any help.  Im in California, & it has to retain all of the OEM stuff (with some exceptions).  Believe it or not I have to get my truck "smogged" every other year (started 4 or 5 years ago).  They dont do a sniffer test, just visual inspection & connect to the ALDL to make sure that its talking & there are no DTC's stored. 

 

I saw briefly last night that someone has the 2002 (ish?) ECM's working on the 98/99 trucks.  I have not looked into it @ all, but will sometime this week.  not sure if there is any benefit for me........... 

 

Bob

 

Well........  now Im getting a P1694 code.  Im going to double check the PCM connectors just to be sure, and start looking for another ECM.

 

Bob

 

good news is that it appears that the Comm Bus wires look to be in good shape & there are no shorts to ground or opens or anything.  I pinned it out between the ECM, PCM & ALDL  & it all looks good. 

 

The bad news is that its still giving me that DTC. 

 

I will make some calls tomorrow & see if I cant find someone that can get me a good ECM. 

 

If anyone has any other things they think I should look into, Im open to it.........

 

thanks

Bob

 

My best advice is to find a shop your willing to work with and then send the ECM to them and have it bench tested. Also while researching the ECM shops make sure to ask about warranty information and turn around times if there is a warranty issue. 

My grids are also disconnected going on my third year now. Just disconnect them from the battery and not the relays and you will get no codes. 

 

I wish I had some advice for you on the ECM, they seem to be at best a crap shoot.

Every April I disconnect my grid heaters and every October I hook them back up. 

Update (hopefully the last for a while.........) :

 

a local shop (Steven Bruce, at Diesel System Services. blacksmokin.com), looked @ the truck & could not find anything wrong with it (other than what I found).  He put his "test ECM" into the truck & it fired up & ran correctly.  WTS light worked properly, Lift pump operated properly & Communications worked properly. 

 

He has a source for ECM's that he said is the company that remanufactures the ECM's for the big 3 & for a lot of the heavy equipment folks.  He ordered me an ECM & had it shipped 2nd day air to Kalipornia (they are in the Easter Time Zone).  Steve was kind enough to allow me to drive the truck for 4 days with his test ECM in it until the new one came in........  

 

installed the new ECM, everything worked fine for 3 days ........... until................  Im completely loaded up & ready to to head out to the desert.  it would crank but not start.  He came out to my house (Thursday night, WAY after hours) & did a bunch of tests & we were able to get it running, however were not sure why.  the last thing we were messing with was the Cam Pos Sensor.  However......... what was strange to me was that with the Cam Pos Sensor unplugged the truck would start & run just fine & would not turn on the CEL until the truck had been running for 13 or 15 seconds.  

I was not comfortable taking everything & everyone out to the desert if we did not "fix" anything, so I told him I would drop it off @ his shop on Friday morning (assuming it would start & run).  I went down to Cummins Friday morning & bought both the Crank & Cam position sensors.  On the way to his shop with the truck it started Bucking & trying to die (the CEL came on), when I took my foot off of the gas pedal.  

 

when I got to his shop he scanned it & it came back with the Crank Pos Sensor DTC.  THAT seems consistent with "some" of the issues I had been having with the truck.  while he was under the hood he swapped both of them & then did a bunch of diagnostics to make sure that everything was happy.  I picked up the truck on Sunday after we got back from Church & paid him for his time on Thursday evening & Friday.  

 

So, some things that came out of this......... 

Steve showed me how to start the truck w/o the key being on & 2 relays removed from the PDC to test to ensure that the Injection pump works properly.  

I dont understand what the Cam position sensor does if the truck will start & run fine w/o it even being plugged in.......................

 

Now I get to fight with the first ECM company & see if they will refund my money for the service they did not provide me (twice), however I have to see if they screwed up my original ECM so badly that the second company will or will not take it as a core........

 

having multiple issues REALLY is a PITA.....  

 

thanks again folks for all of the help during this.  time to replace the heater core and dash & hopefully the old girl is ready for another 100K to 150K before she needs more work.  Im sure the trans will need frictions before then, but that is OK with me.  

 

Bob

 

Edited November 13, 20177 yr by Bobalos

Can you share the ECM rebuilder's name?

The cam sensor on the 98.5-00 trucks effectively is only used for correlation. It has no direct action on the truck. The crank sensor gets all the info it needs and sends it to the ecm & pcm.

23 minutes ago, jlbayes said:

The cam sensor on the 98.5-00 trucks effectively is only used for correlation. It has no direct action on the truck. The crank sensor gets all the info it needs and sends it to the ecm & pcm.

 

Basically only sees TDC #1 that's all being it only a single tooth tone wheel..

37 minutes ago, dripley said:

Can you share the ECM rebuilder's name?

 

The first company I went to was https://carcomputerexchange.com/.  I talked with Brian (their "tech support guy") on numerous occasions.  I was very underwhelmed.  NO technical help whatsoever & could not even tell me for certain what things they did or components they changed.  Even after I explicitly called him & told him I this is what I wanted, BEFORE they even received it.  They had 2 chances @ it & could not get it right.

The second company.......... I dont know, and I dont know that Bruce would tell you.  

Seems weird that they would go through the time & expense to add it to the motor, Harness & software to not do anything with it.  I supposed if it was used in some other application & it was simpler just to just leave it there VS removing it, that kind of makes sense, however being as these motors are explicitly made for Dodge vehicles with Dodge specific ECM's & tuneups...........  just strange to me.  
 

thanks again folks.

Bob