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.
2009 Toyota Yaris L4-1.5L (1NZ-FE)FACTORY OEM SERVICE PROCEDURE
Engine Control System - SFI System
1NZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: TERMINALS OF ECM
TERMINALS OF ECM
HINT: The standard normal voltage between each pair of ECM terminals is shown in the table below. The appropriate conditions for checking each pair of terminals are also indicated. The result of checks should be compared with the standard normal voltage for that pair of terminals, displayed in the Specified Condition column. The illustration above can be used as a reference to identify the ECM terminal locations.
HINT: *: The ECM terminal voltage is constant regardless of the output voltage from the sensor.
1. WAVEFORM 1
2. WAVEFORM 2
HINT: The wavelength varies in accordance with the engine operating condition.
3. WAVEFORM 3
HINT: In DATA LIST, item O2S B1S2 shows the ECM input values from the heated oxygen sensor.
4. WAVEFORM 4
HINT: The wavelength becomes shorter as the engine rpm increases.
5. WAVEFORM 5
HINT: The waveforms and amplitudes displayed differ slightly depending on the vehicle.
6. WAVEFORM 6
HINT: The wavelength becomes shorter as the engine rpm increases.
7. WAVEFORM 7
HINT: The wavelength becomes shorter as the engine rpm increases.
8. WAVEFORM 8
HINT: If the waveform is not similar to the illustration, check the waveform again after idling for 10 minutes or more.
9. WAVEFORM 9
HINT: The wavelength becomes shorter as the vehicle speed increases.
10. WAVEFORM 10
HINT: The duty ratio varies depending on the throttle actuator operation.
11. WAVEFORM 11
HINT: The duty ratio varies depending on the throttle actuator operation.
12. WAVEFORM 12
HINT: The wavelength becomes shorter as the engine rpm increases.
13. WAVEFORM 13
HINT: The waveform varies depending on the CAN communication signal.
14. WAVEFORM 14
HINT: The waveform varies depending on the CAN communication signal.
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- β’ You smell fuel, burning insulation, or see smoke.
- β’ Brakes feel soft, pull hard to one side, or make grinding noises.
- β’ The engine overheats, stalls repeatedly, or misfires under load.
- β’ You are missing required tools, torque specs, or safe lifting equipment.
- β’ You are not confident in the next step or safety outcome.
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