Question's for the RAM Guru's

[HydroRebel]

Hey guys, as the title states I'm hoping someone out there can provide some information on the following issue I've been having. There's a few threads on people having issues with remote starting in the cold and I'm among them. When this first started happening I was checking my battery voltage and over the course of a few days the voltages were all over the place so I went with the assumption that my battery was bad. Well, I've since replaced the stock battery with an Odyssey 94R and the very next day the same thing happened, truck failed to start remotely but can start manually just fine. I checked with a clamp meter after letting the truck sit and I was measuring 1.5-1.6 amps. I started pulling fuses one at a time until I got to F38. Upon pulling this fuse my amps dropped to 20mA. I put the fuse back in and the current never changed. That was just yesterday.

According to the manual F38 fuse is a 10A fuse for the DTCM / Active CL TEMP VLV. So my first question is does anyone know where the DTCM module is located? Next question does anyone know what this valve is referring to (a solenoid perhaps) and why it might be causing a parasitic battery drain. Any info would be greatly appreciated before I make my almost inevitable trip to the dealership.

 

[Grayman5752]

If the truck starts fine manually but not via remote start, a weak battery or draw is not the issue. There are certain inhibitors that will keep remote start from working. Low fuel, check engine light, door open. It could also be a software issue. As for your amp draw test, how long have you let the truck sit before pulling fuses? I’ve had to let some of these DT trucks sit for over an hour before all modules on the bus would go to sleep. My apprentice lost his *** chasing a draw that wasn’t there because he only let a truck sit for about 30 minutes. But to answer your question, the DTCM is located behind the carpet against the firewall in the passenger footwell


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[stevj]

DTCM is Drive Train Control Module.
F38 is in the engine compartment fuse box. It feeds the DTCM.


Steve

 

[Trippi]

if it never works and you just replaced a battery on a brand new truck, take it to the dealer. That is what the warranty period is for, let them fix it and have it documented.

 

[HydroRebel]

If the truck starts fine manually but not via remote start, a weak battery or draw is not the issue. There are certain inhibitors that will keep remote start from working. Low fuel, check engine light, door open. It could also be a software issue. As for your amp draw test, how long have you let the truck sit before pulling fuses? I’ve had to let some of these DT trucks sit for over an hour before all modules on the bus would go to sleep. My apprentice lost his *** chasing a draw that wasn’t there because he only let a truck sit for about 30 minutes. But to answer your question, the DTCM is located behind the carpet against the firewall in the passenger footwell


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Thank you and yes I'm aware of the normal criteria from preventing the remote start from working. I have verified all them are good on my end. The amount of time I let the truck sit probably varied from as little as 5 minutes to maybe 30 minutes. What I did yesterday when I parked the truck was pop the hood prematurely for testing first thing this morning as if you touch the handle to unlock the truck the amp draw goes over 5 amps for a bit with the headlights coming on and all the other stuff. This morning I was reading 20mA.

if it never works and you just replaced a battery on a brand new truck, take it to the dealer. That is what the warranty period is for, let them fix it and have it documented.

Of course, but for reasons I don't want to get into here I was trying to avoid the dealer as we're not currently on good terms from a previous issue. It looks like a trip there is inevitable though.

DTCM is Drive Train Control Module.
F38 is in the engine compartment fuse box. It feeds the DTCM.
View attachment 82844

Steve

Thanks for the diagram very useful and I appreciate the input so far trying to trace down these gremlins.

 

[HydroRebel]

Okay so I just went out and ran a few errands. The truck remote started no problem today. Temperature is much warmer than it had been recently (-16 degrees celcius). When I got home I popped the hood and locked the truck. I'll let it sit for 2 hours and leave the keyfob inside so I don't wake anything up and do an amp draw and see what I get today.

 

[HydroRebel]

Okay so I just went out and ran a few errands. The truck remote started no problem today. Temperature is much warmer than it had been recently (-16 degrees celcius). When I got home I popped the hood and locked the truck. I'll let it sit for 2 hours and leave the keyfob inside so I don't wake anything up and do an amp draw and see what I get today.

I waited a little over 2 hours and checked and the battery was 12.62 volts and no parasitic draw this time. The drain has been happening a lot lately so I expect it to return...fingers crossed that it doesn't.