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Home >> Cadillac >> 1985 >> Eldorado Base, 5.7 N >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> DFI ECM Tests W/Codes (Except FLEETWOOD Fwd) >> Test Procedures >> Switch Test

Switch Test

  1. Enter diagnostics and with code ".7.0" displayed, depress and release brake pedal. This will start switch test procedure and code ".7.1" will be displayed. If code ".7.1" is NOT displayed, refer to "Trouble Code .7.1" diagnostic chart.
    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 wide open position and slowly release. This checks throttle switch for proper operation. Code ".7.3" should appear.
  3. With code ".7.3" displayed, shift transmission into "D" then back to "N". This checks operation of the Drive switch. Code ".7.4" should appear. With code ".7.4" displayed, shift transmission to "R" and back to "P". This checks operation of the Reverse switch. Code ".7.5" should appear.
  4. With code ".7.5" displayed, switch cruise control instrument panel switch on then off. This checks operation of the cruise control switch. Code ".7.6" should appear. With code ".7.6" displayed, switch cruise control instrument panel switch on, then depress and release "Set/Coast" button. This checks operation of the "Set/Coast" switch. Code ".7.7" should appear.
  5. With code ".7.7" displayed, switch cruise control instrument panel switch on, then depress and release "Resume/Acceleration" switch. This checks operation of the "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, then proceed with step 5. Codes will cycle through ECM and be processed as failures.
  6. With code ".7.8" displayed, depress and release the "Instant/Average" button on Fuel Data panel. This checks operation of "Instant/Average" switch. Code ".7.9" should appear. With code ".7.9" displayed, depress and release "Reset" button on Fuel Data panel. This checks operation of the "Reset" switch. Code ".8.0" should appear.
    Fig 1: Fuel Data Panel
    G9207
  7. With code ".8.0" displayed, push "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 (16°C).
  8. 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.
  9. 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. Refer to appropriate diagnostic chart for affected system.
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