Throttle Opener Vacuum Switching Valve (VSV)

Disconnect VSV connector, located near valve cover. Turn ignition on. Using a test light, probe Light Green/Red wire at VSV connector. Light should be on. If light is not on, repair open circuit.
With test light connected to battery voltage, probe Light Green/White wire of VSV connector. Light should be off. If light is on, check circuit for short to ground. If circuit is okay, replace ECM.
With ignition off, remove vacuum hose from throttle opener port on VSV. Connect a hand-held vacuum pump to hose and apply vacuum. Throttle opener should move. If throttle opener does not move, check hose for leaks and kinks. If hose is okay, replace throttle opener.
Reconnect hose to VSV. Remove intake manifold-to-VSV vacuum hose. Connect hand-held vacuum pump to hose and apply vacuum. Throttle opener should move. If throttle opener does not move, check hose for leaks and kinks. If hose is okay, replace VSV. If throttle opener moves, proceed to step 5).
Using test light connected to battery voltage, probe Green/Red wire of VSV connector. Crank engine and note test light. If light is on, proceed to step 8). If light is not on, proceed to step 6).
Turn ignition off. Using test light connected to ground, backprobe Black/Yellow wire terminal of ECM, located under left side of instrument panel near kick panel. Crank engine and note test light. If light is on, proceed to step 7). If light is not on, repair open or ground in cranking signal wire to terminal G11 of ECM. See appropriate wiring diagram in WIRING DIAGRAMS .
If light is on, check for an open in Light Green/White wire between ECM and VSV or defective connections. If no open or defective connections exist, replace ECM.
Turn ignition off. Using test light connected to ground, backprobe Light Green/White wire at ECM. Turn ignition on. Apply vacuum to hose disconnected from intake manifold. Note if throttle opener move. If opener moves, replace VSV. If opener did not move, no problem exists in the system.