PCM "Override" Test Function

The PCM override feature allows testing of certain system functions regardless of normal program instructions. Upon selecting a test, the current operation of that function will be displayed as a percentage of its full range on the ECC panel. The display will alternate between "--" for 1 second followed by the normal program command for 10 seconds. This alternating display is a reminder that the function is not currently being overridden.

Pressing the WARMER or COOLER buttons on the ECC panel initiates the override at which time the display will no longer alternate to "--". Pressing the WARMER button increases the override value while pressing the COOLER button decreases the override value.

Upon release of the button, the display may either remain at the overridden value or automatically return to normal program control. This depends on which function is being overridden at the time. If the display remains at the override value, normal program control can be resumed in one of three ways:

1. Selection of another override test will cancel the current override.
2. Selection of another system (i.e., PCM to BCM) will cancel the current override.
3. On some system overrides, overriding the value beyond either extreme (0 or 99) will display "--" momentarily and the jump to the opposite extreme. If the button is released while "--" is displayed, normal program control will resume and the display will again alternate.

The following is a list of PCM Overrides:

1. ES00
   
   No override is active at this point.
2. ES01
   
   VCC Solenoid.

   • WARMER BUTTON
     
     Solenoid is turned ON when the warmer button is depressed and, ECC will display 99.
   • COOLER BUTTON
     
     Solenoid is turned OFF when the cooler button is depressed and, ECC will display 00.
3. ES02
   
   EGR Solenoid.

   • WARMER BUTTON
     
     Solenoid is turned ON when the warmer button is depressed and, ECC will display 99.
   • COOLER BUTTON
     
     Solenoid is turned OFF when the cooler button is depressed and, ECC will display 00.
4. ES03
   
   ISC Motor.

   • TEST CONDITIONS
     
     Vehicle in Park or Neutral. A/C and EGR are OFF and Spark Advance is at a calculated value, when test is active. When ISC stopped the ECC displays 50. TPS 4° or less.
   • WARMER BUTTON
     
     With engine OFF the ISC plunger will extend until it ratchets once and, ECC will display 99. With engine ON -- will be displayed.
   • COOLER BUTTON
     
     With engine OFF retract ISC, FDC displays 00. With engine ON ISC will retract to base idle.
5. ES04
   
   Injector Cutout (Power Balance).

   • TEST CONDITIONS
     
     Transmission in Park or Neutral. A/C is OFF, ISC is fixed, and Integrator and Block Learn are OFF, when test is active.
   • WARMER BUTTON
     
     Depressing the warmer button will select an Injector and will increment at the rate of one selection per second and, ECC will display injector selected.
   • COOLER BUTTON
     
     Depressing the cooler button will cause Injector Cutoff and, ECC display injector 00.
6. ES05
   
   Fuel Pump Relay.
   NOTE: Vehicle in Park or Neutral. (Engine On), ECC will display 99. (Engine OFF), ECC will displays 00.
   • COOLER BUTTON
     With engine ON, relay OFF, ECC displays 00. Display will return to 99 when the button is released.
NOTE: Engine should be run to charge vacuum reservoir before performing this test. Display will show the percent of servo apply with 99 equaling full retract and 00 equaling full extend. Engine is off when test is performed. "--" will be displayed when engine is running.
7. ES07
   Cruise Servo.

   • WARMER BUTTON
     
     Retract Servo, ECC displays 00 to 99.
   • COOLER BUTTON
     
     Extend Servo, ECC displays 99 to 00.
NOTE: Both cooling fans will run in HI and Low speeds. Each time the WARMER or COOLER button is depressed the state of the relay will change. 0 indicates the relay is de-energized. 1 indicates the solenoid is energized. The Series, Series Parallel, and Parallel relays are energized together to produce high speed.
8. ES08
   Cooling Fan.

   • COOLER BUTTON
     
     Low Relay On/Off, ECC displays 10.
   • WARMER BUTTON
     
     HI Relay On/Off, ECC displays 11.
9. ES09
   
   Fixed Spark.A calculated advance will be displayed when this test is selected. When Cooler button is depressed the first time, spark is fixed at 10°. When the Cooler button is depressed the second time The PCM will calculate a 1 or 2° retard. The PCM will calculate a 1 or 2° advance when the warmer button is depressed. If an advance is selected greater than calculated value "--" will be displayed.

   • COOLER BUTTON
     
     Fixed Spark 10° BTDC, ECC displays 10.
   • COOLER BUTTON
     
     Retard timing, ECC Displays calculated timing.
   • WARMER BUTTON
     
     Advance timing, ECC Displays calculated timing.
10. ES10
    
    Injector Flow. When Cooler button is held down the display will increment at the rate of 1 injector per second. The PCM will energize the injector for 500 milliseconds. An individual injector can be open only once per cycle. The engine must be run before the test can be performed again. This is to prevent engine damage.

    • COOLER BUTTON
      
      Select Injector, ECC displays injector number.
    • WARMER BUTTON
      
      Open Injector, FDC displays 99.
11. ES11
    
    Transmission Shift. Transmission Gear Selector must be in OD position. Vehicle speed under 45 MPH.

    • WARMER BUTTON
      
      Up Shift Command 2-3 or 3-4
    • COOLER BUTTON
      
      Down Shift Command 4-3 or 3-2