Diagnostic Aids
Ensure no mechanical failures are inducing engine knock. See TESTS W/O CODES article in this section.
An intermittent condition may be caused by poor connection, rubbed-through insulation, or a broken wire inside insulation. Check PCM harness connectors for backed-out, improperly mated, broken locks, improperly formed, or damaged terminals, and poor terminal-to-wire connections before component replacement.