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.
Electronic Ignition Timing Retard (Prizm GSi)
On Prizm GSi, a knock sensor, located in rear of cylinder block, sends a variable AC voltage signal to ECM depending on engine detonation. ECM uses this signal to determine if ignition timing should be retarded. Testing information is not supplied by manufacturer. If a fault occurs in the retard circuit, a Code 52 or 53 will set in ECM memory. If a code is set, see G - TESTS W/ CODES article in this section.
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.