1988 Ford Festiva L PlusFACTORY OEM SERVICE PROCEDURE

ECA 23 - Code 17 (Feedback System)

  1. Run engine at 2500 RPM for one minute and recheck code. If code is no longer in memory, problem is intermittent.
  2. If code is still stored, check for intake air leaks. Repair as necessary.
  3. Check for fouled spark plugs. Clean and replace as necessary.
  4. Connect voltmeter between EGO sensor connector and ground. Run engine at 4000 RPM until .55 volt is indicated. Increase and decrease engine speed quickly. Note voltage.
  5. Speeds greater than 4000 RPM should produce a .5-1.0-volt signal. Decreased speed should produce a voltage of 0-.4 volt. If voltage reading is not within specification, replace EGO sensor.
  6. Check voltage at ECA terminal 2D. With key on and engine off, reading should be zero volts. With engine at idle, reading should be .5 volt. With engine running above 2000 RPM, voltage should read .2-.7 volt.
  7. If voltage is incorrect, check for open or short in wiring between EGO sensor and ECA terminal 2D. Repair as necessary. If symptom persists, go to ECA 55  . If voltage is correct, replace ECA.
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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.