Ford OBD1 Systems
ADDITIONAL TESTS FOR EEC-IV SYSTEMS - WIGGLE TEST
3120d 85
10.
When prompted, press the accelerator
pedal once, then release. This activates
the Output State Check and energizes
most of the actuators (relays and
solenoids) that are controlled by the
vehicle's computer.
If your vehicle is equipped with an
Integrated Vehicle Speed Control,
disconnect the vacuum supply
hose from the speed control servo before pressing the
accelerator. Reconnect vacuum hose after test.
11.
To de-energize the actuators, press the accelerator pedal again and
release, the actuators are now de-energized.
12.
The procedure can be repeated as many times as desired by
pressing and releasing the accelerator pedal to energize and de-
energize the actuators.
13.
Consult the vehicle's service repair manual for a list of actuators
(solenoids and relays) controlled by the computer that apply to the
vehicle under test, and which actuators should energize and de-
energize when performing the Output State Check. All applicable
actuators should be on when energized and off when de-energized.
14.
If an actuator is not responding to the Output State Check, follow the
procedures described in the vehicle's service manual to check
computer actuator output circuit voltages and/or grounds.
15.
The Output State Check will stay active as long as desired. To quit
the Output State Check, turn the ignition OFF and disconnect the
Diagnostic Tool from the vehicle.
Wiggle Test
Since any DTC’s from Wiggle Test results are saved in
Continuous Memory, it is suggested that you clear any DTC’s
in Continuous Memory before performing Wiggle Test. This
way you start with a clean slate, and any faults detected during
the procedure will be related to that particular circuit tested.
Use this test to check for intermittent faults in some circuits.
Circuits Tested:
1984 & Newer - Air Charge Temp Sensor (ACT), Barometer Pressure
Sensor (BP), Engine Coolant Temp Sensor (ECT), Exhaust Gas
Oxygen Sensor (EGO), EGR Valve Position Sensor (EVP), Manifold
Absolute Pressure (MAP), Throttle Position Sensor (TP), Vane Air Temp
Sensor (VAT)
1985 & Newer - Vane Air Flow Sensor (VAF)
1986 & Newer - Pressure Feedback EGR Sensor (PFE)
1990 & Newer - Exhaust Gas Oxygen Sensor (EGO), Ignition
Diagnostic Monitor (IDM) (DIS or Dual Plug DIS only), Idle Tracking
Switch (ITS), Mass Air Flow Sensor (MAF)
Summary of Contents for 3120d
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