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.
SFI System (1ZZ-FE): Inspection
- INSPECT INTAKE AIR FLOW METER SUB-ASSY
- Check the operation.
- Apply battery voltage across terminals 1 (+B) and 2 (E2G).
- Using a voltmeter, connect the positive (+) tester prove to terminal 3 (VG) and the negative (-) tester prove to terminal 2 (E2G).
- Blow air into the mass air flow meter, then check that the voltage fluctuates.
If the voltage does not fluctuate, replace the mass air flow meter.
- Check the resistance.
- Using an ohmmeter, measure the resistance between the terminals.
Standard:
TESTER CONNECTION AND SPECIFIED CONDITION SPECIFICATIONTester Connection Specified Condition 4 (THA) -5 (E2) 13.6 to 18.4 kΩ at-20°C (-4°F) 4 (THA) -5 (E2) 2.21 to 2.69 kΩ at 20°C (68°F) 4 (THA) -5 (E2) 0.493 to 0.667 kΩ at 60°C (140°F)
If the result is not as specified, replace the mass air flow meter.
- Check the operation.
- INSPECT CAMSHAFT TIMING OIL CONTROL VALVE ASSY
- Check the resistance.
- Using an ohmmeter, measure the resistance between the terminals.
Standard:
TESTER CONNECTION AND SPECIFIED CONDITION SPECIFICATIONTester Connection Specified Condition 1 (+B)-2 (GND) 6.9 to 7.9 kΩ at 20°C (68°F) If the result is not as specified, replace the camshaft timing oil control valve.
- Check the operation.
- Apply battery voltage across the terminals, then check that the spool valve operates.
NOTE: Check that the spool valve is not stuck.HINT:
The spool valve may not return if foreign objects are caught in it. It may cause subtle pressure leakage to the advance side, and a DTC may be set.
- Check the resistance.
- INSPECT THROTTLE BODY ASSY
- Check the resistance.
- Using an ohmmeter, measure the resistance between the terminals.
Standard:
TESTER CONNECTION AND SPECIFIED CONDITION SPECIFICATIONTester Connection Specified Condition 1 (M-) -2 (M+) 0.3 to 100Ω at 20°C (68° F) 3 (E2) -5 (VC) 2.0 to 4.0 kΩ at 20°C (68°F)
If the result is not as specified, replace the throttle body.
- Check the resistance.
- INSPECT ACCELERATOR PEDAL ASSY
- Check the resistance.
- Using an ohmmeter, measure the resistance between the terminals.
Standard:
TESTER CONNECTION AND SPECIFIED CONDITION SPECIFICATIONTester Connection Specified Condition 3(EP1)-6(VCP1) 1.5 to 6.0 kΩ 1(EP2) -4 (VCP2) 1.5 to 6.0 kΩ
If the result is not as specified, replace the accelerator pedal.
- Check the resistance.
- INSPECT E.F.I. ENGINE COOLANT TEMPERATURE SENSOR
- Check the resistance.
- Using an ohmmeter, measure the resistance between the terminals.
Standard:
TESTER CONNECTION AND SPECIFIED CONDITION SPECIFICATIONTester Connection Specified Condition 1 (E2) -2 (THW) 2.32 to 2.59 kΩ at 20°C (68°F) 1 (E2) -2 (THW) 0.310 to 0.326kΩ at 80°C (176°F)
NOTE: If checking the engine coolant temperature sensor in water, be careful not to allow water to intrude into the terminals. After checking, wipe water off the engine coolant temperature sensor.If the result is not as specified, replace the engine coolant temperature sensor.
- Check the resistance.
- INSPECT KNOCK SENSOR
- Check the resistance.
- Using an ohmmeter, measure the resistance between the terminals.
Standard:
TESTER CONNECTION AND SPECIFIED CONDITION SPECIFICATIONTester Connection Specified Condition 1 (Ground) -2 (Output) 120 to 280 kΩ at 20°C (68°F)
If the result is not specified, replace the knock sensor.
- Check the resistance.
- INSPECT E.F.I. CIRCUIT OPENING RELAY ASSY
- Check the resistance.
- Using an ohmmeter, measure the resistance between the terminals.
Standard:
TESTER CONNECTION AND SPECIFIED CONDITION SPECIFICATIONTester Connection Specified Condition 3-5 10kΩ or higher 3-5 Below 1 Ω (Apply battery voltage to terminal 1 and 2)
If the result is not specified, replace the E.F.I, circuit opening relay assy.
- Check the resistance.
- INSPECT E.F.I ECU RELAY
- Check the resistance.
- Using an ohmmeter, measure the resistance between the terminals.
Standard:
TESTER CONNECTION AND SPECIFIED CONDITION SPECIFICATIONTester Connection Specified Condition 3-5 10kΩ or higher 3-5 Below 1Ω (Apply battery voltage to terminal 1 and 2)
If the result is not specified, replace the E.F.I ECU relay.
- Check the resistance.
Use the Manual With the Right Hardware
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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.
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