Operation CHARM: Car repair manuals for everyone.

Chart 4

Diagnostic Chart (Part 4 Of 5):




Schematic:




At this point in diagnosing a NO START condition it has been determined that PCM inputs and ignition system are ok. This chart will diagnose fuel delivery system.

TEST DESCRIPTION
1. When ignition is turned On fuel pump relay should be energized for about 2 seconds. After connecting a fuel pressure gage ignition may have to be cycled a few times before reaching specified pressure. A Scan tool can also be used to prime fuel system. If pressure is available but low it indicates PCM and fuel pump relay circuit is ok.
2. The PCM sends 12 volts to relay coil.