Dizzle

6.7 2008 Dodge Ram 3500 (with just over 500,000 miles on it)

Hi, I started my truck this morning and left it running for a while (it's -32 outside). When I came back, the odometer said "no bus". The truck was still running, but I couldn't shift or anything. I turned it off and tried to turn it on again. Didn't work.

I disconnected both of my negative battery cables and left the key in the "on" position, to reset the PCM. After that my dash cluster acted up a little, when I tried to start the truck. A couple lights came on and when I opened the door (with the key not in the ignition), it started beeping, like when you leave the keys in the truck. Just now I went back and tried to start it again, but there is no power at all.

Please tell me it's just my battery failing because of the cold. But is there anything I should check? Could someone tell me, where exactly the crank sensor is located?

Dizzle

Alright, now my truck started, but the "check engine" light came on and it says "Perform Service/See Dealer now". My scanner is giving me the following codes:

U1421 - Implausible Ignition Key Off Time Received
P0700 - Transmission Control System (MIL Request)
U0001 - High Speed CAN Communication Bus
U0141 - Lost Communication with Body Control Module "A"

Is it just the cold or should I have it checked out?

6.7L MegaCab

Sounds like your truck did the exact same thing my truck did about a month ago when I was trying to leave work. We had a cold front come through, below 20 deg where I work. Truck started just fine, then everything went wacky, shut her down. Got same codes as your last two. Then she wouldn't start and my black maxx wouldn't communicate either so I couldn't clear the codes. After about 30 min of turning the ignition on and off, the ecm woke up and I was able to clear the codes and start the truck. When the high speed bus loses communication the truck won't start.

Sent from my DROID X2 using Tapatalk 2

mega-engr

Definitely could be your batteries and also the cold weather. Check the batteries out.

Dr.Dizzle

Hey look who it is.....

It could be the batteries! I suggest you have them load tested. Also be sure to clean the battery cable ends, terminals and all of the ground connections. They each must be tight as well.

Dizzle

Alright, I just came back from a trip down to Indiana. On the first day the temperature never went higher than -13 Fahrenheit, but the truck ran without any problems. Check engine light went away after third start.

I'm planning on leaving again tomorrow and wanted to start the truck just now. It didn't. Got the "No bus" message again. Also, I used an adapter on my block heater cord, that lights up, when electricity is flowing through. When I attached it to my truck, the light went out and I couldn't hear my block heater start up. It's -14 Fahrenheit outside right now.

I will have the batteries load tested tomorrow. I really hope, it's just that. Thanks for the advice.

Dizzle

Went outside again and started the truck. All kinds of lights came on, though. Headlights started acting up. "No bus" message came and went. I turned it off. Wasn't able to start it again. At first I was able to put it in Drive, but after a minute it just started going crazy.

BigIron70

Sounds like you may have a bad TIPM. Clear codes turn key on and off three times, is there more than one module with active DTCs “Logged Against” the TIPM then replace the TIPM, Code U0001 active you could have a short in another module, best to follow diagnostic for this code first to confirm for sure you don't have another module shorted first. Do that before condemning the TIPM.

Dizzle

Thanks BigIron70, I will try that tomorrow. If it really is my TIPM, how much will it cost to have it fixed?

BigIron70

They are not cheap, around $460 plus programing and any diagnostic time and R&R. Depending on dealer rate could be 2 hours labor. Dealer price will be more, for sure list $685
http://www.factorymopar.com/?i=2&mak...30420&fl_id=41

Dizzle

Last night I attached a different cable to my block heater. Just now I went outside and started the truck.
Before, I deleted all the codes. The truck started with no problems.
No check engine light, no "no bus" message, no flashing lights. I will let it run for a while and check again.
My dad thinks, it's because the block heater wasn't working (because of my broken cable) and that's why the truck acted up.