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.
1990 Ford Festiva L Plus, StandardFACTORY OEM SERVICE PROCEDURE
Engine Controls - Sensor Operating Range Charts: Introduction
Sensor operating range information can help determine if a sensor is out of calibration. An out-of-calibration sensor may not set a trouble code, but it will cause driveability problems.
NOTE:
All voltage tests should be performed with a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in test procedure.
VANE AIRFLOW METER TERMINAL RESISTANCE
| Across Terminals | Fully Closed Ohms | Fully Open Ohms |
|---|---|---|
| E2-Vs | 20-400 | 20-1000 |
| E2-Vc | 100-300 | 100-300 |
| E2-Vb | 200-400 | 200-400 |
| E2-THA | -4°F (-20°C) 13.6-18.4k | -4°F (-20°C) 13.6-18.4k |
| E2-THA | 68°F (20°C) 2.2-2.7k | 68°F (20°C) 2.2-2.7k |
| E2-THA | 140°F (60°C) 500-700 | 140°F (60°C) 500-700 |
| E1-Fc | Infinite | 0 |
ENGINE COOLANT TEMPERATURE SENSOR RESISTANCE
| Temperature °F (°C) | Resistance Ohms |
|---|---|
| -4 (-20) | 14,600-17,800 |
| 68 (20) | 2,300-2,700 |
| 176 (80) | 200-400 |
O2 SENSOR VOLTAGE
| O2 Terminal to Ground (1) | Volts | ||
|---|---|---|---|
| 4000 RPM | .55 V | ||
| More Than 4000 RPM | .5-1.0 V | ||
| Less Than 4000 RPM | 0-0.4 V | ||
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THROTTLE POSITION SWITCH (TPS) RESISTANCE
| Test Condition (1) | Continuity Between IDL-TL | Continuity Between PSW-TL | ||
|---|---|---|---|---|
| .02" (.5 mm) | Yes | No | ||
| .03" (.7 mm) | No | No | ||
| Wide Open Throttle | No | Yes | ||
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Factory Service Tools
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.
