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: Inspection
- INSPECT MASS AIR FLOW METER
- Check the output voltage.
- Apply battery voltage across terminals 1 (+B) and 2 (E2G).
- Using a voltmeter, connect the positive (+) tester probe to terminal VG, and negative (-) tester probe to terminal E2G.
- Blow air into the MAF meter, and check that the voltage fluctuates.
- Measure the resistance between terminals 4 (THA) and 5 (E2).
STANDARD:Condition Specified Condition -20°C (-4°F) 13.6 to 18.4 kΩ 20°C (68°F) 2.21 to 2.69 kΩ 60°C (140°F) 0.493 to 0.667 kΩ If the result is not as specified, replace the MAF meter.
- Check the output voltage.
- INSPECT CAMSHAFT TIMING OIL CONTROL VALVE ASSY
- Using an ohmmeter, measure the resistance between the terminals.
Standard: 6.9 to 7.9 Ω at 20°C (68°F)
- Connect the battery's positive (+) lead to terminal 1 and negative (-) lead to terminal 2. Check the movement of the valve.
OK:
If operation is not as specified, replace the valve.
- Using an ohmmeter, measure the resistance between the terminals.
- INSPECT ACCELERATOR PEDAL ROD ASSY
- Measure the resistance between the terminals.
STANDARD:Tester Connection Specified Condition 2 (VPA2) - 3 (EP1) 5.0 kΩ or less 5 (VPA1) - 1 (EP2) 5.0 kΩ or less 6 (VCP1) - 3 (EP1) 1.5 to 6.0 kΩ 4 (VCP2) - 1 (EP2) 1.5 to 6.0 kΩ If the result is not as specified, replace the pedal assy.
- INSPECT THROTTLE BODY ASSY
- Measure the resistance between the terminals.
STANDARD:Tester Connection Condition Specified Condition 2 (M+) - 1 (M-) 20°C (68°F) 0.3 to 100 Ω 5 (VC) - 3 (E2) 20°C (68°F) 1.2 to 3.2 kΩ If the result is not as specified, replace the throttle body assy.
- INSPECT ENGINE COOLANT TEMPERATURE SENSOR
- Measure the resistance between the terminals.
STANDARD:Condition Specified Condition Approx. 20°C (68°F) 2.32 to 2.59 kΩ Approx. 80°C (176°F) 0.31 to 0.326 kΩ If the result is not as specified, replace the sensor.
NOTE: If checking the ECT sensor in the water, keep the terminals dry. After the check, wipe the sensor dry. - INSPECT KNOCK SENSOR
- Using an ohmmeter, measure the resistance between the terminals.
Standard: 120 to 280 kΩ at 20°C (68°F)
If the result is not as specified, replace the sensor.
- INSPECT RELAY (Marking: EFI MAIN, C/OPN)
- Remove the EFI and C/OPN relays from the engine room R/B.
- Measure the resistance of the relay.
STANDARD:Terminals Specified Condition 3 - 5 10 kΩ or higher 3 - 5 Below 1 Ω (when battery voltage is applied to terminals 1 and 2) If the result is not as specified, replace the relay.
- INSPECT RELAY (Marking: F/PMP)
- Remove the F/PMP relay from the engine room R/B.
- Measure the resistance of the F/PMP relay.
STANDARD:Terminals Specified Condition 3 - 4 Below 1 Ω 3 - 4 10 kΩ or higher (when battery voltage is applied to terminals 1 and 2) If the result is not as specified, replace the relay.
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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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