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Home >> Acura >> 1990 >> Legend L, 4D Sedan, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes >> Code 17: Vehicle Speed PULSER
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Code 17: Vehicle Speed PULSER

NOTE: For wiring diagrams, see WIRING DIAGRAMS article. For vacuum diagrams, see VACUUM DIAGRAMS article.
  1. Operate cruise control. If cruise control does not function properly, repair cruise control prior to proceeding with test. If cruise control functions properly, proceed to next step.
  2. Turn ignition off. Connect ECU test harness between ECU and ECU connector. Disconnect test harness connector "B" from main wiring harness side. Turn ignition on. Check voltage between test harness terminals B11 (positive) and A18 (negative). See Figure . Voltage should be approximately 5 volts.
  3. If within specification, proceed to step 4). If not within specification, substitute a known good ECU. If condition goes away, replace original ECU.
  4. Turn ignition off. Reconnect ECU connector "B". Block rear wheels and set parking brake. Raise front of vehicle and support with safety stands. Turn ignition on. Slowly rotate left front wheel and measure voltage between ECU terminals B11 (positive) and A18 (negative). If voltage pulses between zero and 5 volts, failure is intermittent.
  5. Check for poor or loose connections at speed pulser and ECU. If voltage does not pulse between 0-5 volts, check if voltage holds at zero or 5 volts. If voltage holds at 5 volts, repair open in Yellow/Red wire between ECU terminal B11 and speed pulser. If wire is okay, replace speed pulser.
  6. If voltage holds at zero volts, repair short in Yellow/Red wire between B11 and speed pulser. If wire is okay, replace speed pulser. If speed pulser is okay, substitute a known good ECU and recheck. If specified voltage is now available, replace original ECU.
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