I am posting for a friend. Tom owns a 2008 2500 megacab with a Cummins and 5spd. 4wd srw. Our kids race MX together. A couple months ago he was coming home from a race. He stopped for fuel and the engine would crank but not start. He had it towed to the dealer and they said the ECM had crashed. The reloaded the info and it runs. But after getting it back, the "wait to start" lght comes on at times. It will derate the power also. Here is the kicker. It only comes on while towing his toy hauler. He has a small enclosed trailer and the light does not come on towing it. He took it back to the dealer and they said the problem was in the trailer. So he took it to Camping World and their techs said it was a truc issue. Last night he came over and we took my hauler down thw road. Th light came on with my trailer also. So now we know it is a truck issue. BAck to the dealer today. They first said it was na injector. But after checking them and fuel pressures all is ok. Now they say they have no Idea why the light comes on. I think it is electrical in nature.I know this a long post, but I needed to include all the details. Anyone have any suggestions?

 

Welcome to the forum.

Sounds like maybe either a ground issue or the added load from the amount of trailer lights if the larger trailers have more lighting. Weak battery or alternator maybe?

 

Maybe, but he towed the same trailer all summer. I was thinking maybe the intake air temp sensor, relay or maybe the thermostat that tells the ecm it is cold enuf to turn on the intake heater?

 

TIPM issue?

 

tipm?

 

totally integrated power module.

It's like a computerized fuse box, from what I gather. It's also a $900 fix for random electrical problems.