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Home >> Cadillac >> 1982 >> Seville 4.1L Eng VIN 4 >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> DFI Control System >> Diagnostic Procedure >> Engine Malfunction Test Procedure
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Engine Malfunction Test Procedure

  1. Enter diagnostics and record stored trouble codes. Begin diagnosis with lowest numbered code which is recorded. If codes "51" or "16" are shown, begin diagnosis with code "51", then proceed to code "16".
  2. If "intermittent failures "13", "20", "33", "39", "44" or "45" are displayed, use diagnostic chart for corresponding "hard failure" code.
  3. Code "51" (if detectable by ECM) indicates faulty PROM installation. Refer to TROUBLE CODE  51 in this article for diagnosis of this code.
  4. Code "63" indicates that cruise control was engaged and vehicle speed exceeded maximum limit. Clear code and road test vehicle.
  5. Code "64" indicates that cruise control was engaged and vehicle acceleration exceeded preset rate which was programmed into ECM. This could be caused by icy or wet pavement. Clear code and road test vehicle.
  6. Code "65" indicates that cruise control was engaged and coolant exceeded maximum temperature. Check cooling system, clear codes and road test vehicle.
  7. Code "66" indicates that cruise control was engaged and engine speed exceeded maximum allowable limit. This code can be caused by removing engine load (transmission in neutral) when cruise control is engaged and operating. Clear codes and road test vehicle.
    NOTE: After diagnosing trouble codes; switch tests, engine data displays and output cycling tests can be used to isolate "intermittent failures". DO NOT perform any adjustment or repairs on any component until malfunction has been positively located.
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