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Home >> Cadillac >> 1990 >> DeVille V8-273 4.5L >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Testing and Inspection >> Initial Inspection and Diagnostic Overview >> - Description of On-Board Diagnostics >> Diagnostic Displays >> PCM/ECM Display >> Overides

Overides

After .7.0 is displayed on the FDC, the PCM/ECM Override test can be initiated by depressing the HI button on the FDC panel. When the HI button has been depressed, the FDC will display E.9.5. At this time depress the ECON and WARMER buttons on the FDC panel at the same time. E.5.0 will be displayed on the FDC. The HI and LO buttons can be used to select a specific override test. The FDC will alternately display the test code and the information specific for that override. The warmer and cooler buttons are used to activate the override test.

E.5.0 No Overrides.

E.5.1 VCC SOLENOID
WARMER BUTTON:The VCC solenoid override is energized when the warmer button is depressed and the VCC will be engaged, FDC will display E.5.1 and 99 alternately.
COOLER BUTTON: The solenoid is de-energized when the cooler button is depressed and VCC will not be engaged, FDC will display E.5.1 and 00 alternately.

E.5.2 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, FDC will display E.5.2 and 99 alternately.
COOLER BUTTON: The solenoid is de-energized when the cooler button is depressed and no vacuum signal to the EGR valve, FDC will display E.5.2 and 00 alternately.

E.5.3 ISC MOTOR
TEST CONDITIONS:
^ Vehicle must be in Park or Neutral.
^ A/C relay is OFF and EGR solenoid is de-energized. Spark advance is at an PCM/ECM calculated value, when test is active.
^ When ISC motor is stopped the FDC displays E.5.3 and 50.
WARMER BUTTON:
(Engine off) The ISC plunger will extend until it ratchets once and the FDC will display E.5.3 and 99 alternately.
(Engine on) 8.8.8 will be displayed.

COOLER BUTTON:
(Engine off) Retract ISC, FDC displays E.5.3 and 00 alternately.
(Engine on) ISC will retract to base idle.

E.5.4 INJECTOR CUT-OUT
TEST CONDITIONS:
^ Vehicle must be in Park or Neutral, engine running.
^ A/C relay is OFF and 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 the FDC will display injector selected.
COOLER BUTTON: Depressing the cooler button will cause injector cut-off and the FDC will display E.5.4 and 00 alternately.

E.5.5 FUEL PUMP RELAY
TEST CONDITIONS:
^ Vehicle must be in Park or Neutral.
^ Engine On FDC will read E.5.5 and 99 alternately.
^ Engine Off, FDC will read E.5.5 and 00 alternately.
COOLER BUTTON:
Engine on, relay off, the FDC displays E.5.5 and 00. the display will return to 99 when the button is released.

E.5.6 AIR SYSTEM
WARMER BUTTON: Electric Switching Valve (ESV). Each time the warmer button is depressed the state of the valve will change. The right digit of the FDC indicates the state of the ESV. 0 indicates the solenoid is de-energized. 1 indicates the solenoid is energized.
COOLER BUTTON: Electric Divert Valve (EDV) On/Off. Each time the cooler button is depressed the state of the valve will change. The left digit indicates the state of the EDV. 0 indicates the solenoid is de-energized. 1 indicates the solenoid is energized.

E.5.7 CRUISE SERVO
WARMER BUTTON: Retract Servo, FDC displays E.5.7 and 00 to 99.
COOLER BUTTON: Extend Servo, FDC displays E.5.7 and 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. 8.8.8 will be displayed when engine is running.

E.5.8 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 FDC should display E.5.8 and 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 FDC should display E.5.8 and 10.

E.5.9 FIXED SPARK
WARMER BUTTON: Advance timing, FDC displays calculated timing.
COOLER BUTTON: The first time the cooler button is depressed the PCM will fix the spark 10 degrees BTDC, FDC displays E.5.9 and 10.
COOLER BUTTON:Retard timing, FDC displays E.5.9 and calculated timing.
NOTE:
1. E.5.9 and 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 8.8.8 will be displayed.
6. Vehicle must be in Park or Neutral, engine running.

E.6.0 INJECTOR FLOW
WARMER BUTTON: Open injector, FDC displays E.6.0 and 99.
COOLER BUTTON: Select injector, FDC displays E.6.0 and 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.

E.6.1 TRANSMISSION SHIFT (91 MODELS ONLY)
NOTE: This override is not active. The FDC will display "8.8.8".
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