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Entering Switch Test

WARNING: This page is about a different car, the 1990 Cadillac Fleetwood and 1990 Cadillac DeVille. However, it is still accessible from the selected car via links, so may be relevant.
  1. With ".7.0" displayed on the FDC, the ECM switch test is initiated by placing the cruise control switch in the ON position and depressing the brake pedal. (To cause ".7.0" to be displayed on the FDC, see INTRODUCTION TO DIAGNOSTIC TESTING  under DIAGNOSTIC TESTING).
  2. After brake pedal has been depressed, FDC will display "E.7.0". At this point, the HI and LO buttons on the ECC panel can be used to select the specific switch test desired. See step 3) which follows for a complete list of ECM switch tests.
  3. When a specific switch test has been selected and that switch activated, the display will alternately display the code for the test and "00" to confirm the switch is working. Following is a list of ECM switch tests accompanied by a test description:
    • "E.7.1" Viscous Converter Clutch (VCC) Brake Switch  This test detects the open and close of the VCC brake switch at terminal C4 of the ECM. See Figure . To activate test, depress brake pedal.
    • "E.7.2" Throttle Switch  This test detects the open and close of the nose switch of the Idle Speed Control (ISC) at terminal A7 of the ECM. See Figure . To activate test, depress accelerator pedal.
    • "E.7.3" 3rd Gear Pressure Switch  This test detects the open and close of the transmission 3rd gear pressure switch at terminal C10 of the ECM. See Figure . Operate transmission in 3rd gear to perform test.
    • "E.7.5" Cruise Control On/Off Switch  This test detects the open and close of the cruise switch mounted on the dash at terminal D2 of the ECM. See Figure . To activate test, place switch in the ON position.
    • "E.7.6" Cruise Control Set/Coast Switch  This test detects the set-coast switch in the turn signal lever at terminal D8 of the ECM. See Figure . To activate test, depress the set-coast button.
    • "E.7.7" Cruise Control Resume/Acceleration Switch  This test detects the close of the resume/accel switch in the turn signal lever at terminal C3 of the ECM. See Figure . To activate test, slide the resume/accel switch.
      NOTE: The cruise switch must be on to perform this test.
    • "E.7.8" Power Steering Pressure Switch (PSPS)  This test detects the open and close of the power steering switch located on the steering gear at terminal C9 of the ECM. See Figure . To perform test, start engine and turn wheels from straight ahead to full right or left and then return to straight ahead. While this action is being performed, the ECM checks the power steering pressure switch for proper operation.
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