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
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