Ford Explorer, Maintaince And Repair Manual

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During the CCD mode, both edges of the SPOUT signal are utilized. The leading edge of the SPOUT signal is
used by the ICM in the same manner as during the push start mode. The falling edge of the signal is generated
to control the timing for turning the ignition coil on (the ICM no longer controls this function as during the
push start mode). During the CCD mode, the coil on time, or dwell, is entirely controlled by the PCM through
the SPOUT signal.
In the event that the SPOUT signal from the PCM is disrupted, the ICM will use the PIP signal from the CMP
to fire the ignition coil, which results in a fixed spark angle and dwell.
Diagnosis and Testing
SERVICE PRECAUTIONS
Always turn the keyOFFand isolate both ends of a circuit whenever testing for shorts or continuity. •
Never measure voltage or resistance directly at the processor connector. •
Always disconnect solenoids and switches from the harness before measuring for continuity,
resistance or energizing by way of a 12−volt source. •
When disconnecting connectors, inspect for damaged or pushed−out pins, corrosion, loose wires, etc.
Service if required. •
PRELIMINARY CHECKS
Visually inspect the engine compartment to ensure that all vacuum lines and spark plug wires are
properly routed and securely connected. 1.
Examine all wiring harness and connectors for insulation damage, burned, overheated, loose or
broken conditions. Ensure that the ICM is securely fastened to the front fender apron. 2.
Be certain that the battery is fully charged and that all accessories are OFF during the diagnosis. 3.
TEST PROCEDURES
Perform the test procedures in the order in which they are presented here.
Ignition Coil Secondary Voltage Test
CRANK MODE
Connect a spark tester between the ignition coil wire and a good engine ground. 1.
Crank the engine and check for spark at the tester. 2.
Turn the ignition switch OFF. 3.
If no spark occurs, check the following:
Inspect the ignition coil for damage or carbon tracking. 1.
Check that the distributor shaft is rotating when the engine is being cranked. 2.
If the results in Steps a and b are okay, go to Module Test. 3.
4.
If a spark did occur, check the distributor cap and rotor for damage or carbon tracking. Go to the
Ignition Coil Secondary Voltage (Run Mode) Test. 5.
HOW TO USE THIS BOOK
SYSTEM OPERATION 171