Diagnostic Aids

Using scan tool, monitor electrical load parameter. When rear defogger and/or headlights are turned on, scan tool should indicate on. When rear defogger and/or headlights are turned off, scan tool should indicate off.

An intermittent condition may be caused by a poor connection, rubbed-through insulation, or a broken wire inside insulation. Check PCM connectors for backed-out terminals, improper mating, broken locks, damaged terminals, or poor terminal-to-wire connections before component replacement.