Preliminary Check

WARNING: This page is about a different car, the 1994 Ford Ranger. However, it is still accessible from the selected car via links, so may be relevant.

Perform following checks:

Inspect engine compartment to ensure all vacuum hoses and spark plug wires are properly routed and securely attached.
Check all wiring harness connectors for damaged pins and loose or broken conditions.
Ensure ICM mounting screws are tight.
Ensure battery is fully charged.
Ensure all accessories are turned off during diagnosis.

NOTE: A 12-volt incandescent test light should not be used to test CID, IDM, PIP or SPOUT circuit signals. It will load circuit and may cause incorrect measurements or faulty ICM/PCM operation.

NOTE: Perform all ignition voltage and resistance tests at breakout box connected to diagnostic cable unless otherwise specified.