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.
1994 Subaru Impreza BaseFACTORY OEM SERVICE PROCEDURE
Throttle Position Sensor/Switch
NOTE:
All testing procedures are performed with engine at normal operating temperature.
- Turn ignition on. With throttle fully closed, measure and record voltage to ground at specified ECM terminals. Open throttle fully. Repeat voltage measurements. See TPS VOLTAGE SPECIFICATIONS table.TPS VOLTAGE SPECIFICATIONS
Terminal Voltage Throttle Closed No. 4 0.4-0.5 No. 11 0 No. 15 4.4-5.5 Throttle Closed No. 4 3.5-4.3 No. 11 0 No. 15 4.4-5.5 - If necessary, loosen retaining screws and rotate TPS until correct voltages are obtained. Replace TPS if voltage cannot be adjusted to specification.
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.
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