Ford OBD1 Systems
ADDITIONAL TESTS FOR EEC-IV SYSTEMS - RELAY AND SOLENOID TEST
100 3160g
8.
If the vehicle's computer fails to enter Cylinder Balance Test mode,
do the following:
Lightly press the accelerator pedal again as described in step 7
above.
9.
After the Cylinder Balance Test is completed, the test results are
sent to the Scan Tool.
The computer compares the power
contribution that each cylinder
makes to engine operation.
10.
If all cylinders are contributing equally,
the computer determines that power
distribution is normal and a “System
Pass” message will display.
If the computer detects a problem with a cylinder(s) when
performing the initial Cylinder Balance Test, it needs to repeat the
test two more times to properly determine which cylinder or cylin-
ders are malfunctioning. If this is the case, the Scan Tool will
display the “Lightly press the accelerator half way and release”
message again instead of the “System Pass”. Proceed to step 11.
11.
If a cylinder is not contributing at the same level as the other
cylinders, the computer prompts you to repeat the test two more
times by displaying the “Lightly press the accelerator half way and
release” message again. Each time the message displays, perform
the procedures as instructed.
12.
After the repeat Cylinder Balance tests
have completed, the computer will identify
which cylinder (or cylinders) are not
contributing equally, and will send this
information to the Scan Tool’s LCD
display.
If any weak cylinders are identified,
consult the vehicle’s service repair
manual to perform further testing
and/or repairs.
Relay and Solenoid Test (Output State Check)
The "Output State Check" is a special program in the vehicle's computer
that allows the user to energize (turn ON) and de-energize (turn OFF),
on command, most of the actuators (relays and solenoids) that are
controlled by the computer.
Use this test to check computer output voltages and relay/solenoid
operation.
The fuel injectors and fuel pump are not energized during this
test. Check your vehicle thoroughly before performing any test.
See BEFORE YOU BEGIN on page 31 for details.
ALWAYS
observe safety precautions whenever working on a
vehicle.
Read and follow Safety Precautions on page 3 before
performing this test.