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.
Engine Controls - System/Component Tests 1.0 & 1.3L: Introduction
Before testing separate components or systems, perform basic diagnostic procedures in the BASIC TESTING article. Since many computer-controlled and monitored components will set a Diagnostic Trouble Code (DTC) if they malfunction, it is also recommended that self-diagnostics be performed. See the TESTS W/CODES article.
DO NOT disconnect PCM electrical connectors, battery cables, PCM ground wire harness or PCM memory power input 15-amp fuse before checking for DTCs. Any stored DTCs will be erased from PCM memory when power is removed from PCM.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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.