Operation CHARM: Car repair manuals for everyone.

Chart 3 OF 4

Diagnostic Chart:




Wiring Diagram:






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

DIAGNOSTIC AIDS

When attempting to diagnose an intermittent problem, use the Scan tool to review malfunction history diagnostic information. The supplemental data an be used to duplicate a problem.

Intermittents or opens suspected to be at the connector can be detected by using diagnostic service probe. Voltage can be read on wires without disconnecting any connectors.

TEST DESCRIPTION

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

2. The ignition must be Off for about 10 seconds before the fuel pump relay will be re-energized. If the test light illuminates at the fuel pump fuse the PCM control and relay are ok.

3. The PCM sends 12 volts to the relay coil.