• Welcome to EcoDieselRam.com We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your EcoDiesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • We believe in quality OVER quantity, and a family friendly place for your #EcoDiesel home!
    CLICK HERE TO REGISTER! Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

2015 Ecodiesel Low Voltage

nkhagen

New Member
Dec 17, 2019
6
4
Truck Year
2015
Long running issue, truck is currently at the dealer. In case someone comes across similar issues here's the story

Truck ran 100% fine prior to emissions tune. After I picked it up I got a warning chime and low voltage message on my drive home.
Truck went back for EGR and this. EGR was replaced, this continued.
GDE ECM went in the truck and the low voltage issue never returned (6 months).
Emissions ECM was put back in and the voltage issue immediately returned.

The system charges fine 99.9999% of the time. When the issue occurs, all the gauges jump, shifts get messed up, and cruise control gets shut off (have to press "on" again).

It ONLY happens with the truck warmed up, usually engine temp above 180 or so, and ONLY on coast. IE if I jump on the highway and set the cruise it won't happen for hours. But when I coast, foot off the gas like approaching a stop, it triggers the issue. It only does it 1x per trip. Will not repeat unless you sit idling for awhile and then take off again or shut the truck off and restart.

Its not bump nor water sensitive, it's not ambient temp sensitive. And it doesn't do it with the GDE ECM.

It's currently in the shop, their first diagnosis was the wiring on the driver's frame rail under the driver's seat and they wanted me to authorize $300 in labor to start ripping my wiring apart. I explained that I had already looked into that and reiterated the specific conditions with which to make the issue appear. And I told them I had tried a secondary ECM (my buddy has a twin truck) and that solves the issue. I'll update when I hear back from them and when it's fixed, I'm guessing they're still going to want to go down the wiring path since that's what RAM told them to try.

Anyone else run into this? Any yes the battery and alternator are tested and good. It does set codes, loss of communication etc but it wouldn't set a check engine light until I cleared everything stored in the memory last weekend and then suddenly the check engine light illuminated.

Side note to anyone experiencing issues with no check engine light, clear ALL the codes (I used Bluedriver which clears all the systems from ABS to Trailer Controller) and see if it'll trip the light. For whatever reason it refused to light it with all the codes it had stored.

Nick
 

nkhagen

New Member
Dec 17, 2019
6
4
Truck Year
2015
Update: They replaced the ECM as I requested after some intense discussion between service writer and his top mechanics. Got her back and the issue is gone! All covered under warranty. No more weird issues.
 

John

Well-Known Member
Nov 13, 2015
1,186
386
Update: They replaced the ECM as I requested after some intense discussion between service writer and his top mechanics. Got her back and the issue is gone! All covered under warranty. No more weird issues.
Great news!
 

Luke scrimsher

New Member
Jan 13, 2022
1
0
Truck Year
2016
Long running issue, truck is currently at the dealer. In case someone comes across similar issues here's the story

Truck ran 100% fine prior to emissions tune. After I picked it up I got a warning chime and low voltage message on my drive home.
Truck went back for EGR and this. EGR was replaced, this continued.
GDE ECM went in the truck and the low voltage issue never returned (6 months).
Emissions ECM was put back in and the voltage issue immediately returned.

The system charges fine 99.9999% of the time. When the issue occurs, all the gauges jump, shifts get messed up, and cruise control gets shut off (have to press "on" again).

It ONLY happens with the truck warmed up, usually engine temp above 180 or so, and ONLY on coast. IE if I jump on the highway and set the cruise it won't happen for hours. But when I coast, foot off the gas like approaching a stop, it triggers the issue. It only does it 1x per trip. Will not repeat unless you sit idling for awhile and then take off again or shut the truck off and restart.

Its not bump nor water sensitive, it's not ambient temp sensitive. And it doesn't do it with the GDE ECM.

It's currently in the shop, their first diagnosis was the wiring on the driver's frame rail under the driver's seat and they wanted me to authorize $300 in labor to start ripping my wiring apart. I explained that I had already looked into that and reiterated the specific conditions with which to make the issue appear. And I told them I had tried a secondary ECM (my buddy has a twin truck) and that solves the issue. I'll update when I hear back from them and when it's fixed, I'm guessing they're still going to want to go down the wiring path since that's what RAM told them to try.

Anyone else run into this? Any yes the battery and alternator are tested and good. It does set codes, loss of communication etc but it wouldn't set a check engine light until I cleared everything stored in the memory last weekend and then suddenly the check engine light illuminated.

Side note to anyone experiencing issues with no check engine light, clear ALL the codes (I used Bluedriver which clears all the systems from ABS to Trailer Controller) and see if it'll trip the light. For whatever reason it refused to light it with all the codes it had stored.

Nick
Hello, hope you are doing well. I am having something very similar happen, and when it happens low voltage pops up on the dash. Like you said only happens once a drive. Do you think it’s the same thing?
 
Top