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 Storm GSi, AutomaticFACTORY OEM SERVICE PROCEDURE
Engine Controls - Tests W/Codes
- Introduction
- Self-Diagnostic System
- Summary
- Diagnostic Code Charts
- Notes
- Diagnostic Circuit Check
- Chart A-1, Won't Flash Code 12, No Check Engine Light
- Chart A-2, No ALDL Data Or Won't Flash Code 12, Check Engine Light On At All Times
- CODE 13, HEATED OXYGEN (O2) SENSOR CKT, OPEN CKT (GSi)
- CODE 13, NON-HEATED OXYGEN SENSOR CKT, OPEN CKT (EXCEPT GSi)
- Code 14, Coolant Temp Sensor (Cts) CKT High Temp Indicated
- Code 14, Coolant Temp Sensor (Cts) CKT, Low Temp Indicated
- Code 21, Throttle Position Sensor CKT, Signal Voltage High
- Code 21, Throttle Position Sensor CKT, Signal Voltage Low
- Code 23, Intake Air Temp (IAT) Sensor CKT, Low Temp Indicated
- Code 23, Intake Air Temp Sensor CKT, High Temp Indicated
- Code 24, Vehicle Speed Sensor (VSS) Circuit
- Code 32, EGR System Error (CALIF. Only)
- Code 33, Map Sensor Circuit, Signal Voltage High - Low Vacuum
- Code 33, Map Sensor Circuit, Signal Voltage Low - High Vacuum
- Code 42, Electronic Spark Timing (Est) Circuit
- CODE 44, HEATED O2 SENSOR CKT, LEAN EXHAUST INDICATED (GSi)
- CODE 44, NON-HEATED O2 SENSOR CKT, LEAN EXHAUST INDICATED (EXCEPT GSi)
- CODE 45, HEATED O2 SENSOR CKT, RICH EXHAUST INDICATED (GSi)
- CODE 45, NON-HEATED O2 SENSOR CKT, RICH EXHAUST INDICATED (EXCEPT GSi)
- Code 51, ECM Failure, ECM Failed Or Prom Failure
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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