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Entering ECM Output Overrides

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, (to cause ".7.0" to be displayed on the FDC, see INTRODUCTION TO DIAGNOSTIC TESTING  under DIAGNOSTIC TESTING), depress HI button on ECC panel and display will change from ".7.0" to "E.9.5". Simultaneously depress ECON and WARMER button on ECC panel and display will advance from "E.9.5" to "E.5.0", signaling the beginning of the output override cycle.
  2. To advance display to higher numbered override, depress the HI button on the ECC panel. If test conditions are not appropriate for performing test, the ECC panel will display "X" (X being 3 parallel lines). This display will continue until test conditions are corrected or test is by-passed. To return to a lower numbered output override, depress the LO button on the ECC panel.
  3. Following is a listing of the available overrides, each with an accompanying explanation:
    • "E.5.1" Viscous Converter Clutch (VCC) Override  Upon selecting this mode the ECM controls the VCC at normal operating parameters. Technician can initiate an override by pushing the WARMER button on the ECC panel to switch on the VCC solenoid or by pushing the COOLER button on ECC panel to turn off the VCC solenoid. Override continues only while button is depressed.
    • "E.5.2" EGR Override  While in this mode the ECM displays the amount of EGR flow on a scale of "00" (no flow) to "99" (full flow). If the WARMER button on ECC panel is depressed, the EGR is commanded on until the button is released. If COOLER button on ECC panel is depressed, the EGR is commanded off until the button is released. The ECM controls the EGR at normal operating parameters when no button is depressed.
      NOTE: The EGR test will have little significance with the engine at idle. This is because a positive backpressure type of EGR valve is used.
    • "E.5.3" ISC Override  While in this mode, the Idle Speed Control (ISC) motor can be commanded and held to a fully retracted position through the use of the ECC panel COOLER and WARMER buttons. Vehicle must be standing still and the transmission in park or neutral. Depressing the COOLER button on the ECC panel causes ISC to retract and remain in this position while button is depressed, FDC will display "00". Depressing the WARMER button on the ECC panel causes the ISC motor to extend until the throttle switch closes, The ECC panel will display "99". When throttle switch closes, normal control of the ISC is restored.
      NOTE: During this test the A/C compressor clutch is commanded off, the EGR is commanded off and the spark advance is fixed.
    • "E.5.4" Injectors 1-8 Override  While in this mode, each of the 8 fuel injectors can be individually selected and turned off using the ECC panel WARMER and COOLER BUTTONS. Transmission must be in park or neutral. Depressing the WARMER button on the ECC panel selects the injector number to be tested. With the WARMER button depressed and held, the injector number will increment at a rate of one per second and displayed on the FDC. Depressing the COOLER button on the ECC panel turns off the selected injector and "00" is displayed on the FDC. The selected injector will remain off while the COOLER button remains depressed.
    • "E.5.5" Fuel Pump Relay Override  While in this mode the fuel pump relay is commanded off using the ECC panel COOLER button. Transmission must be in park or neutral. Depressing and holding the COOLER button on the ECC panel causes FDC to display "00", indicating fuel pump relay has been de-energized. Releasing the COOLER button causes "99" to be displayed and normal control of the fuel pump relay is resumed.
    • "E.5.6" Air Solenoids Override  While in this mode the state of the air DIVERT solenoid is changed each time the COOLER button on the ECC panel is depressed. When "10" is displayed, this indicates the air divert solenoid is energized. "00" indicates the air divert solenoid is de-energized. The state of the air SWITCH solenoid is changed by depressing the WARMER button on the ECC panel. With the air switch solenoid energized, "01" is displayed. "00" indicates air switch solenoid is de-energized. When "11" is displayed, this indicates both the divert and air switch solenoid are energized.
    • "E.5.7" Cruise Servo Feedback Override  While in this mode, the cruise control servo position can be changed using the ECC panel WARMER and COOLER buttons. Depressing the WARMER button on the ECC panel retracts the cruise servo and increases commanded servo position one percent at time to a maximum of 100 percent. Depressing COOLER button on the ECC panel will command a decrease in servo position and extend the cruise servo one percent at a time to a minimum of zero percent. The FDC will display the current commanded cruise control servo position in percent.
      NOTE: To ensure sufficient vacuum is available to operate the cruise control servo, engine should be run and then shut off immediately prior to using the cruise control override. The cruise override test cannot be performed with the engine running.
    • "E.5.8" Coolant Fans Override  While in this mode the COOLER button on the ECC panel is depressed to invert the state of the low speed fan relay. "00" is displayed on FDC with fans not running. With fans running at low speed and the low speed relay energized, the FDC displays "10". Depressing WARMER button on the ECC panel will invert the high speed fans operation. With the fans running at high speed, "11" will be displayed on the FDC, indicating the high and low speed fan relays are energized.
    • "E.5.9" Fixed Spark Override  While in this mode, spark advance is controlled manually and displayed on the FDC in degrees. The first time the COOLER button on the FDC panel is depressed and released, spark angle is fixed at 10° BTDC. The second and subsequent times the COOLER button is depressed, spark timing is retarded 1° to 2° until 0° TDC is reached. Each time the WARMER button on the ECC panel is depressed, spark is advanced 1° to 2° until the ECM controlled spark advance present when override was initiated is again reached. Spark advance cannot be advanced beyond original setting and attempt to do so will cause FDC to display "888".
    • "E.6.0" Injector flow Override  While in this mode each of the fuel injectors can be individually selected and energized once per engine run cycle. The injector to be tested is selected by depressing and holding the COOLER button on the ECC panel. The FDC will display the injector number which it will increment at a rate of one per second. Depressing the WARMER button on the ECC panel energizes the displayed injector for 500 milliseconds. Each injector can be energized only once per engine cycle to avoid possible engine flooding. "888" will be displayed and the override disabled if an attempt is made to energize an injector which has already been energized.
    • "E.6.1" Not Used  This mode is not currently used. The FDC will display "888" if this mode is selected.
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