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.
1988 Chevrolet Spectrum ExpressFACTORY OEM SERVICE PROCEDURE
Code 43 (EST Detonation Control)
- Check connection between detonation sensor and harness. If connection good, disconnect wire at sensor and turn ignition on. Check voltage between sensor harness connector and ground.
- If reading is less than 4 volts or over 6 volts, check circuit A23 for shorting to ground or shorting to voltage.
- If reading in step 1) is 4-6 volts, check resistance across detonation sensor terminal to ground. Reading should be 2550-3450 ohms. If reading is bad, replace detonation sensor. If reading is good, check for weak connections at terminals.
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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