EEC-IV Monitor Measurement Methods
CHANGE CONDITION TO CAUSE RESPONSE BY INPUTPurpose: To verify the sensor receives and responds to changes.
1. Key ON engine OFF/RUNNING; AUTO or DCV mode.
2. Select sensor on pin selector "A".
3. Create a condition or change a condition.
4. Observe the change in sensor value. Verify the change with the appropriate graph or chart.
Examples: Move the throttle, watch the Throttle Position (TP) and Manifold Absolute Pressure (MAP) sensor values. Warm up the engine, watch the Air Charge Temperature (ACT) and Engine Coolant Temperature (ECT) values decrease. Depress the brake pedal, watch the BOO light.
CHANGE CONDITION AND VERIFY OUTPUT RESPONSE.
Purpose: To verify EEC module and actuator circuit responds to sensor input.
1. Key ON engine OFF/RUNNING; AUTO or DCV mode.
2. Select actuator on pin selector "A".
3. Create a change for the input device with the switchbox or vehicle operation.
4. Observe the change in the actuator signal and observe the light.
Examples: Increase throttle position (accelerate), observe SPOUT increase. Move Exhaust Gas Oxygen (EGO) switch to lean, observe SPOUT increase.
CHECK VALUE
Purpose: To verify the correct value for a device or signal.
1. Key ON engine OFF/RUNNING; AUTO or DCV mode.
2. Select signal from pin selector "A" or "B".
3. Since various units are used, refer to meter function light.
CLICK TESTING (RELAYS/SOLENOIDS)
Purpose: Activate solenoid or relay from monitor and observe device.
1. Key ON engine OFF; AUTO or DCV mode.
2. Select the relay or solenoid signal on pin selector "A" and correct ground on reference pin selector.
3. Insert switchbox into selector pin jacks.
4. Push the small red button to turn ON relay or solenoid.
5. Listen for a click and observe the signal light for illumination.
COIL RESISTANCE (SOLENOIDS/RELAYS)
Purpose: Measure for correct resistance value of device.
1. Key OFF; Ohms mode.
2. Select signal from pin selector "A".
3. Select correct ground from reference pin selector.
4. Select ohms range switch.
5. Wiggle test light will illuminate and the speaker will sound. Press the wiggle test reset button.
6. Manual test light should be blinking, value in ohms units.
EEC-IV INPUT CHECK (STO)
Purpose: Confirm that the Engine Control Assembly (ECA) sets CHECK ENGINE LIGHT for certain EEC sensors.
1. Key ON engine OFF; DCV mode.
2. Select sensor from pin selector "A".
3. Set reference pin selector to signal return (sig rtn).
4. Insert switchbox into selector pin jacks.
5. Move the AIM switch to key ON engine OFF position.
6. Push the small red button on switch box and observe STO light turn ON and speaker sound while the button is pressed.
7. Return the AIM switch to the OFF position.
HARNESS OPENS
Purpose: Check harness for open circuits.
1. Key OFF; ohms mode.
2. Select signal from pin selector "A".
3. Disconnect the sensor/actuator where the signal is to be checked.
4. Connect a jumper wire from reference pin jack (black) to signal pin on harness to be tested.
5. Check for continuity.
HARNESS SHORTS
Purpose: Check harness for short to ground or power.
1. Key OFF; ohms mode.
2. Select signal from pin selector "A".
3. Set ohms range switch to 200K.
4. Disconnect the sensor/actuator to be tested.
5. Disconnect the EEC-IV processor, then reconnect monitor to EEC-IV harness (optional).
6. Select various power or ground signals from reference pin selector. Example: reference voltage (VREF), signal return (SIG RTN), power ground (PWR GND).
7. Read resistance: 10K or less indicates a short, higher than 10K indicates no short.
OUTPUT STATE CHECK (SOLENOIDS/RELAYS)
Purpose: Exercise actuator devices after key ON engine OFF self test.
1. Key On Engine OFF; AUTO or DCV mode.
2. Move AIM switch to key ON engine ON position and wait for output codes (beeps) to end.
3. Completely depress and release the throttle. Observe the signal light turn ON.
4. Completely depress and release the throttle. Observe the signal light turn OFF.
5. Return AIM switch to OFF position.
WIGGLE TESTING (DCV OR OHMS)
Purpose: Sensitive DCV or ohms testing for intermittent harness or device.
1. Key OFF for ohms wiggle; key ON engine OFF/RUNNING for DCV wiggle.
2. Use DCV wiggle for all actuators, power and grounded signals, all sensors which use DCV units in AUTO mode; all others use ohms wiggle.
Examples: ohms wiggle MAP, INJ; DCV wiggle - TP, ECT. DCV wiggle is more sensitive than the ohms wiggle test.
3. Select the proper signal from pin selector "A".
4. Select the correct ground from reference pin selector.
5. Tap components, wiggle and flex the harness and connectors.
6. The wiggle and test light will activate when a change is sensed.