2007 DENALI/Error message while towing

[Glenn5ft19]

2007 Denali 6.2 L
While towing a 3000 lb trailer with electric brakes. Service Traction control and Stabil link error messages keep flashing. Check engine light comes on too. I only get those messages while towing. I’m using the regular 6 pin connector with a centre ground.
suggestions?

 

[Geotrash]

2007 Denali 6.2 L
While towing a 3000 lb trailer with electric brakes. Service Traction control and Stabil link error messages keep flashing. Check engine light comes on too. I only get those messages while towing. I’m using the regular 6 pin connector with a centre ground.
suggestions?

Need to get the code for what's triggering the CEL. Could be a range of things from fuel pressure issues to misfires. Note that the TC/stabilitrak message gets triggered when the engine isn't running right. Happens to me when I tow with my 2012 sometimes as well, but I don't get a CEL. How many miles on the truck and does it have the original fuel pump in the tank?

 

[Glenn5ft19]

79k miles. Probably has the original fuel pump. In 2020 I had a bad problem with vapour lock in the fuel line While towing. I wrapped the fuel line with heat reflective shield. Other people on line had experienced that problem and spent a lot of money at dealerships replacing fuel pumps etc. that did not fix the problem but insulating the fuel line from the heat of the transmission did. My next plan of attack is to replace the plugs and high tension leads.

 

[Fless]

Why not get the CEL code so you can focus on the root cause?

 

[Glenn5ft19]

Why not get the CEL code so you can focus on the root cause?

Time to replace the plugs anyway. The CEL goes out when the trailer is disconnected and you drive for a couple of minutes.

 

[BG1988]

2007 Denali 6.2 L
While towing a 3000 lb trailer with electric brakes. Service Traction control and Stabil link error messages keep flashing. Check engine light comes on too. I only get those messages while towing. I’m using the regular 6 pin connector with a centre ground.
suggestions?

check the codes