Chart A-1 No Malfunction Indicator Lamp (MIL)

Chart A-1:

MIL-Service Engine Soon:

CIRCUIT DESCRIPTION
When the ignition switch is turned "ON" (engine "OFF,") except for a brief flash, the MIL should remain "ON."

Battery voltage is applied directly to the lamp via the INDIC fuse (I/P fuse block), and 40 amp fusible element (right side underhood electrical center). The Powertrain Control Module (PCM) provides the ground for the MIL when the ignition is "ON," and engine "OFF."

TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.

1. If the PCM fuse is blown, refer to "Malfunction Indicator Lamp" under Instrument Panel, Gauges and Warning Indicators.
2. Using a test light connected to 12 volts, probe each of the system ground circuits to be sure a good ground is present. Refer to "PCM Connector View" for PCM pin locations of ground circuits.

DIAGNOSTIC AIDS:
Engine runs OK, check:

^ Faulty light bulb.
^ CKT 419 open.
^ INDIC fuse blown. This will result in no stop lamps, oil or generator lights, seat belt reminder, etc.

Engine cranks but will not run, check:

^ Continuous battery - fuse or fusible link open.
^ PCM fuse open.
^ Battery CKT 540 to PCM open.
^ Ignition feed CKT 439 to PCM open.
^ Poor connection(s) to PCM.