Diagnostic Aids

An open, a short to voltage, a short to ground or a defective sensor inside distributor can prevent reference voltage from pulsing at PCM resolution terminal. If Code 16 does not reset and vehicle still does not start, go to NO START - ENGINE CRANKS OKAY in BASIC TESTING article in this section.

Fig 1: Code 16 Schematic (5.7L) Opti-spark Ignition System Low Resolution Pulse

Fig 2: Code 16 Diagnostic Flow Chart (5.7L) Opti-spark Ignition System Low Resolution Pulse