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.
System Description
SYSTEM DESCRIPTION
ECM conducts feedback control of the engine idle speed to the target value, by controlling intake air volume with electric throttle, according to driving conditions such as engine warm-up condition, A/C loads, electric loads, etc.
IDLE SPEED FEEDBACK
ECM determines control target value based on the engine coolant temperature, A/C operation status, gear position, etc., then conducts feedback control to match the target value when idle judgment is made with transmission range switch signal ON, or when the vehicle speed is very low. Also, adjustment of the engine idle speed is conducted by ECM's self learning (IDLE AIR VOLUME LEARNING).
CORRECTION OF BATTERY VOLTAGE
When battery voltage becomes lower than specified value, ECM corrects the target value to improve battery charging.
OTHER CORRECTIVE CONTROLS
- When some electric load (power steering load, electric load, etc.). is turned ON, ECM controls target engine speed for each load accordingly.
- When gear position is selected (N→D, D→N), ECM controls the engine speed by optimizing throttle opening to minimize shift shock.
- When deceleration (accelerator pedal ON→OFF), ECM controls the engine speed by optimizing throttle opening to minimize shift shock and exhaust gas emission.
NO RELATED
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.