Reduced Power When Headlights Activated

[1320feet]

First off, This is a 2005 2500hd Silverado with a 8.1.

I get trouble code u0107 when headlights or AC are activated.

The code reads lost communication with TAC Module.

 

This reduced power code first appeared with turning on the AC.

 

The next day it would also set when the auto headlights came on,

 

Now when the code sets, the RPM increases by about 500 rpm.

 

If I hit the high beams the engine stalls.

 

If I disconnect one headlight at the headlight the engine stalls.

 

Sometimes when I turn the key off after the reduced power sets, the engine remains running with most of the lights in the instrument cluster flashing. When I turn the key back to the run position the engine stalls.

[1320feet]

Thanks Guys

I found a broken ground wire on the back of the left cylinder head.

[gmtech4]

you will not get to much help here,you got probs bud,take it in.

 

keep us posted with what they do/find

[redvett]

Clean and check ALL chassis,engine & body grounds before going in for repair.