Throttle Opener Control System
- Disconnect electrical connector at throttle opener vacuum Switching Valve (SV), located in front of valve. SV contains a 2-pin connector with Light Green/White and Blue/Black wires.
- Turn ignition on. Using test light connected to ground, probe Blue/Black wire at SV connector. If test light glows, go to next step. If test light does not glow, check for open circuit in Blue/Black wire between SV and EFI main relay. EFI main relay is mounted on ECM, located under left side of instrument panel, near kick panel. See Figure .
- With test light connected to battery voltage, probe Blue/Black wire of SV electrical connector. If test light does not come on, go to next step. If test light comes on, check for short to ground in Light Green/White wire between SV and ECM. ECM is located under left side of instrument panel, near kick panel. If wiring is okay, replace ECM.
- With ignition off, remove vacuum hose from throttle opener port on SV. Connect a hand-held vacuum pump to hose, and apply vacuum. If throttle opener does not move, check hose for leaks and kinks. If hose is okay, replace throttle opener. If throttle opener moves, go to next step.
- Reconnect vacuum hose to SV. Remove intake manifold-to-SV vacuum hose at intake manifold. Connect hand-held vacuum pump to hose, and apply vacuum. If throttle opener moves, go to next step. If throttle opener does not move, check hose for leaks and kinks. If hose is okay, replace SV.
- 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 moves. If throttle opener moves, replace SV. If throttle opener does not move, system is okay.