Ignition Relay Diagnosis

CIRCUIT DESCRIPTION
The ignition relay supplies ignition voltage to the following components:
^ The glow plugs
^ The fuel injection control module (FICM)
^ The engine control module (ECM)
^ The fuel rail pressure regulator
^ The mass air flow (MAF) sensor
^ The fuel heater
^ The A/C compressor relay
^ The daytime running lamps
^ The rear defogger

DIAGNOSTIC AIDS
If the IGN relay fails open:
^ The scan data WILL be available.
^ The vehicle WILL crank, no start.
^ The dash indicator lights WILL illuminate.

TEST DESCRIPTION

Ignition Relay Diagnosis - Steps 1-6:

Ignition Relay Diagnosis - Steps 7-14:

The numbers below refer to the step numbers on the diagnostic table.
4. This step tests the ignition 1 relay control circuit from the ECM.
5. This step isolates the circuit from the IGN relay. All of the circuits at the relay are good if the test lamp illuminates.