Folowing here is engine control module (ECM) wiring diagram and the instruction installation for GMC trucks. This GMC truck ECm wiring connection and installation especially for LLY engine option. As you knew, engine code LLY, require different ECM pins and connector pin locations then shown in the main installation manual. ECM connector C1 is Blue and requires the purple wire supplied inserted into pin 45, see page 3 of these instructions. If a purple wire exists in pin 45 of connector C1, then it has been pre-installed and you can connect to the end of it. If no purple wire exists in pin 45 then install the one supplied. The other end of the purple wire needs to replace the orange wire in the harness. To remove the orange wire from the receptacle, the white locking devise must be removed, it has an internal lock which is accessible from the bottom, press the lock tab and remove the locking devise. To release the terminal from the receptacle a lock tab must be depressed, insert a release tool or a small drill bit to depress the lock tab. Look at the replacement terminal for the lock tab location. Insert the terminal of the purple wire into the receptacle to replace the orange wire and install the locking devise. Ful wiring diagram here.
GMC Trucks ECM Installation Wiring Diagram LLY Engine
September 10, 2009 by Leave a Comment