Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
3.1L Engine
ECM operates a Electronic Vacuum Regulator Valve (EVRV) to control vacuum to the EGR valve. Regulator normally allows only a small amount of vacuum to pass to EGR valve. When ECM grounds EVRV drive circuit, EVRV opens, allowing enough vacuum to pass through to open EGR valve. ECM monitors EGR effectiveness by periodically checking fuel integrator counts. This is done when vehicle speed is greater than 50 MPH, MAP sensor signal indicates cruise condition, throttle position is constant and all conditions have been met twice for 60 seconds.
- With ignition on and engine off, EVRV should not be energized or allow enough vacuum through to open EGR valve. When test terminal "B" of the ALDL connector is grounded, EVRV will energize, allowing vacuum to the EGR valve.
- Checks for plugged EGR passages. If passages are plugged, engine may have severe detonation on acceleration.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.