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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 >> Switch Test Procedure
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Switch Test Procedure

  1. Enter diagnostics and with code ".7.1" displayed, begin switch test procedure. To begin switch test procedure, depress and release brake pedal. Code ".7.1" should appear.
    NOTE: Each test action must be performed within 10 seconds after codes appear on display panel or ECM will store code as failure and proceed to next code.
  2. With code ".7.1" displayed, depress and release brake pedal again. Code ".7.2" should appear. With code ".7.2" displayed, depress throttle to an open position and release. Code ".7.3" should appear.
  3. With code ".7.3" displayed, shift transmission into drive then back to neutral. Code ".7.4" should appear. With code ".7.4" displayed, shift transmission to reverse and back to park. Code ".7.5" should appear.
  4. With code ".7.5" displayed, switch cruise control on, then off. Code ".7.6" should appear. With code ".7.6" displayed, switch cruise control on, then depress and release "Set/Coast" button. Code ".7.7" should appear. With code ".7.7" displayed, switch cruise control on, then depress and release "Resume/Acceleration" switch. Code ".7.8" should appear.
    NOTE: To pass codes "7.5", ".7.6" and ".7.7" on vehicles without cruise control, allow codes to appear for 10 seconds each and proceed with step 5  ). Codes will cycle through ECM and be processed as failures.
  5. With code ".7.8" displayed, depress and release "INSTANT/AVERAGE" button on Fuel Data panel. Code ".7.9" should appear. With Code ".7.9" displayed, depress and release "RESET" button. Code ".8.0" should appear.
    Fig 1: Diagram of Fuel Data Panel With Blank Display During Diagnostic Testing
    G09340324Courtesy of GENERAL MOTORS COMPANY
  6. With code ".8.0" displayed, depress and release "OUTSIDE TEMP" button twice. This test checks ECM's ability to recognize and process air conditioning clutch signal. This test may require engine running with A/C operating in "Auto" mode with temperature selection set at 60° F.
  7. When switch tests are completed, ECM will display codes which did not pass test. Each code will appear beginning with lowest code. Codes will not disappear until affected switch circuit is repaired and retested. After switch tests are completed, ECC will display code ".0.0" and return to code ".7.0". Code ".0.0" indicates all switch circuits are operating properly (remember that ".0.0" will never be obtained on vehicles without cruise control).
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