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.
1992 Geo Prizm Base, AutomaticFACTORY OEM SERVICE PROCEDURE
EFI Main Relay
- EFI main relay is located in fuse/relay block on left front side of engine compartment. Remove EFI main relay from fuse/relay block.
- Using ohmmeter, ensure continuity exists between pin No. 1 (Black/Orange wire) and pin No. 2 (White/Black wire). Apply battery voltage to pin No. 1 (Black/Orange wire) and ground pin No. 2 (White/Black wire). Continuity should exist between remaining pins or wires on EFI main relay. Replace EFI main relay if continuity is not as specified.
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:
- • 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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