d61mccarty

Here are a couple pics of the relay and the wiring. Its goes where the trailer cable goes into the trailer. Mine had a box with a terminal strip inside. 12v 30 amp Auto relay.jfif

I have a 2019 GMC Sierra SLE. and found the same issue with my Furrion 3 camera set. After some playing around I found that if I jumper the trailer 7 way connector Batt and tail/marker light pins the cameras will operate. but not plugged into truck. After research I found that their is not enough current (power) to power the cameras. I installed a relay where the trailer light is connected and use the 12v to power the tail/marker lights. The relay coil is energized by the truck tail lights so no damage will be done to the truck trailer control module. Problem solved.

In my case the batteries were fully charged they just came off a four day charge at the camp site and were plugged in the full time. I check my trailer batteries every season with a load tester. And both batteries are only 8 months old.

Just a follow up to the original problem. Since the ECM was replaced we towed the travel trailer many times without any issues. the truck runs flawlessly. I am concerned about have the latest brake and brake pad wear recalls done with all the problems resulting from the update. They are now scheduled for Jan.20th.

I had the exact something happen to me. My truck had 561 miles on it and after all the above messages showed it wouldn't start. Called GM roadside and had it towed to the dealer and it started and I drove it off the rollback. Mil light stayed on. Dealer couldn't duplicate the problem went over the engine and transmission wiring and didn't find anything. They called the factory and they said to replace the ECM and reprogram. They did this and no problems since.

The trailer was plugged into the truck during travel. I was waiting in the sewage dumping line when the truck quite. As said above the dealer stated it was a ECM failure. If they wanted breakend to last 2000 miles they should have said so. I waited the 500 they specify. The warranty will cover the repair and the tow.

I will check mine when I get the truck back and if it shows hot when the engine is off I'll be pulling the trailer battery fuse #63 out of the truck fuse box. I plug the trailer in at the house and when camping remotely I use a generator. The trailer batteries will hold while travelling.

Well the Dealer Service Dept. just called and the ECM has a problem in it its not communicating properly. They will have one by noon tomorrow and installed and programmed by the end of the day. I asked about the trailer and the tech said there is a relay on the trailer battery circuit and the engine must be running to charge the trailer. It is disconnected when the engine is off.

2019 GMC Crew short box Max Tow two weeks old 561 miles. We towed the 8.000 lbs. travel trailer 30 miles to the lake and I couldn't ask for a better truck.Until on the way out of the campground I was waiting in the sewer dump line and the truck shut off and the auto shut down was already disabled by the switch. The DIC was throwing warnings faster than I could read them. Reduced Engine Power, Service vehicle soon, I called on star on the demo time period and the scanned it saying "Engine out of spec" "Transmission not performing to spec". And "Battery power low". The push button start was green but would not start the engine. And all the accessories was on Radio,clement control, windows and door locks would work. i had a friend pull me out of the sewage line and he took my trailer home with my unhappy wife and two dogs. While awaited the tow truck to the dealer I was trying to reset the push button start to at least shut it off to save the battery and I held it in for about 20 seconds and the green led on it went out. I the attempted to start it and it fired right up. Still showing a check Engine light in the Tach. window. It drove up on the roll back and off the roll back at the dealer. I will be at the dealer service department 8 am tomorrow to try to get it straightened out.