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
High Altitude Operation
- With ignition on and engine stopped, disconnect high altitude switch connector terminals C and D. See Fig 1 . Check voltage at connector terminal C. If voltage is less than 10 volts, go to step 3). If voltage is greater than 10 volts, check Black wire ground. If okay, go to next step.
- Connect jumper wire to connector terminal C, ground jumper wire repeatedly. High altitude solenoid should click. If solenoid clicks, solenoid is okay. If solenoid does not click, replace solenoid.
- Check for open or grounded Orange or Blue wires. If okay, remove ECM connector terminal No. 18 and check voltage to ground. If voltage is greater than 10 volts, replace ECM. If voltage is less than 10 volts, repair open or ground.
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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