What circuit is the EGR solenoid? I have a 1991 Z28 1LE 5.7 automatic. In checking the EGR Solenoid circuit i took a test light and tested it across the 2 terminals that connect to the EGR Solenoid. Well the manual says that the test light should come on if the circuit is okay. The light did not come on. I grounded each terminal with the test light. The pink/black wire came on but the gray wire did not(or is it a green wire?). Anyways i need to know what circuit the other wire is i think gray or green colored. I did check the ohms resistance of the EGR Solenoid and it checked in at about 25 ohms. I guess i need to check for an open in the gray/green wire and just maybe my computer is bad.

With the engine running and at full operating temperature, the EGR circuit should cycle on and off rapidly. The resistance of the solenoid coil should be adequate at 25 ohms. One of the wires will have constant power in this mode, and the other (grounding lead) is switched by the ECM.

Make sure the engine is operating in closed loop, or perform the test in the Field Service mode (ingnition on, engine not running, ALDL terminal B grounded). This should force the EGR solenoid to cycle raapidy. If the grounding lead does not switch, start checking connections at the ECM and the wiring between the ECM and EGR solenoid.

So your saying the Pink/Black wire is a constant voltage and other wire gray or green is a Ground wire? Do you know what circuit the ground wire is?