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.
1989 Geo Spectrum 2D Hatchback, StandardFACTORY OEM SERVICE PROCEDURE
Tests W/Codes
- Introduction
- Check Engine Light
- Retrieving Codes
- Trouble Code Id Chart
- Clearing Codes
- Summary
- Diagnostic Circuit Check
- System Performance Check
- A1, Lean Exhaust
- A2, 15-20° Fixed Dwell
- A3, Dwell Fixed Over 50°
- A4, TPS Circuit Check
- A5, "CHK Eng" Lite INOP
- A6, "CHK Eng" Lite On
- A7, Fuel Cut-Off System
- Code 12, No Dist Reference
- Code 13, O2 Sensor Circuit Open
- Code 14, Cts CKT Hi Temp
- Code 15, Cts CKT Low Temp
- Code 21, TPS & Idle Switch
- Code 22. Fuel Cut-Off Relay
- Code 23, M/C Solenoid
- Code 25, Air Injection System
- Code 42, Fuel Cut-Off Volt Hi
- Code 44, Lean Exhaust
- Code 45, Rich Exhaust
- Code 51, Prom Error
- Code 53, Air VSV Circuit
- Code 54, M/C Signal Hi
- Code 55, Prom Error
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.