My 2011 GMC Sierra won't start by key with just the T harness THAR-GM4 completely plugged in.

Question

With the T Harness plugged into both connections without the EVO-ALL connected the key will not start the engine.  If I disconnect the CAN Bus connecter and reconnect the factory CAN Bus connecter the truck starts by my key.  So I guess my question comes down to does the EVO-ALL have to be plugged into the T Harness for me to use my key? The harness is THAR-GM4

Answer 1

Need to connect at least the RED connector to the EVO. Immo power is interupted which is why you cannot start with the key