Override

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.

ES00 No overrides.

ES01 VCC SOLENOID
WARMER BUTTON: The VCC solenoid override is energized when the warmer button is depressed and the VCC will be engaged, ECC will display 99.
COOLER BUTTON: The solenoid is de-energized when the cooler button is depressed and VCC will not be engaged, ECC will display 00.

ES02 EGR SOLENOID
WARMER BUTTON: The EGR solenoid override is energized when the warmer button is depressed and the EGR valve will receive a vacuum signal, ECC will display 99.
COOLER BUTTON: The solenoid is de-energized when the cooler button is depressed and no vacuum signal to the EGR valve, ECC will display 00.

ES03 ISC MOTOR
TEST CONDITIONS:
^ Vehicle must be in Park or Neutral.
^ A/C relay is OFF and EGR solenoid is de-energized.
^ When ISC motor is stopped the ECC displays 50.
^ TPS 4 degrees or less.
WARMER BUTTON:
(Engine off) The ISC plunger will extend until it ratchets once and the ECC will display 99.
(Engine on) "--" will be displayed.

COOLER BUTTON:
(Engine off) Retract ISC, FDC displays 00.
(Engine on) ISC will retract to base idle.

ES04 INJECTOR CUT-OUT
TEST CONDITIONS:
^ Vehicle must be in Park or Neutral, engine running.
^ The desired engine rpm should be selected before selecting this override, as the ISC will be fixed at a selected rpm.
WARMER BUTTON: Depressing the warmer button will select an injector and will increment at the rate of one selection per second, and the ECC will display injector selected.
COOLER BUTTON: Depressing the cooler button will cause injector cut-off and the ECC will display 00.

ES05 FUEL PUMP RELAY
TEST CONDITIONS:
^ Vehicle must be in Park or Neutral.
^ Engine On ECC will read 99.
^ Engine Off, ECC will read 00.
^ No button depressed, normal operating mode.
COOLER BUTTON:
Engine on, relay off, the ECC displays 00. the display will return to 99 when the button is released.

ES07 CRUISE SERVO
WARMER BUTTON: Retract Servo, ECC displays 00 to 99.
COOLER BUTTON: Extend Servo, ECC displays 99 to 00.
NOTE:
1. Engine should be run to charge the vacuum reservoir before performing the test.
2. Display will show the percent of servo apply with 99 equaling full apply (retract) position and 00 equaling full relaxed (extended) position.
3. Engine is OFF when test is performed. "--" will be displayed when engine is running.

ES08 COOLING FAN
WARMER BUTTON: Hi relay: Each time the warmer button is depressed the state of the relay will change. A 1 on the right digit indicates that the relay is energized. 0 indicates that the relay is de-energized. To properly energize the circuit for high speed operation the ECC should display 11.
COOLER BUTTON: Low relay: Each time the cooler button is depressed the state of the relay will change. A1 on the left digit indicates that the relay is energized. 0 indicates that the relay is de-energized. To properly energize the circuit for low speed operation the ECC should display 10.

ES09 FIXED SPARK
WARMER BUTTON: Advance timing, ECC displays calculated timing.
COOLER BUTTON: The first time the cooler button is depressed the PCM will fix spark 10 degrees BTDC, ECC displays 10.
COOLER BUTTON:Retard timing, ECC displays calculated timing.
NOTE:
1. A calculated advance will be displayed when this test is selected.
2. When cooler button is depressed the first time, spark is fixed at 10 degrees.
3. When the cooler button is depressed the second time the PCM will calculate a 1 or 2 degree retard.
4. The PCM will calculate a 1 or 2 degree advance when the warmer button is depressed.
5. If an advance is selected greater than calculated value "--" will be displayed.
6. Vehicle must be in Park or Neutral, engine running.

ES10 INJECTOR FLOW
WARMER BUTTON: Open injector, FDC displays 99.
COOLER BUTTON: Select injector, ECC displays injector number.
NOTE:
1. When cooler button is held down the display will increment at the rate of 1 injector per second.
2. The PCM will energize the injector for 500 milliseconds.
3. An individual injector can be open only once per cycle. The engine must be run before the flow test for that injector can be performed again. This is to prevent engine damage.

ES11 TRANSMISSION SHIFT
WARMER BUTTON: Up shift command 2-3 or 3-4.
COOLER BUTTON: Down shift command 4-3 or 3-2.
NOTE:
1. Transmission gear selector must be in the Drive position.
2. Vehicle speed under 45 MPH.