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.
Air Injection System
All Federal models without 4WD and all California models are equipped with computer-controlled air injection systems. The ECM monitors coolant temperature and activates a timer.
When coolant temperature is below 95°F (35°C), the ECM issues a command to solenoid valve I. The solenoid valve opens, admitting intake manifold vacuum to open the air suction valve(s) through the cutoff valve(s) for about 2 minutes.
After the time has elapsed, the ECM issues a command to solenoid valve I to close the vacuum passage. The solenoid valve closes and this closes the cutoff valve(s).
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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.