Chart A-1 No Malfunction Indicator Lamp (MIL)

Chart A-1:

MIL And PCM Circuits:

CIRCUIT DESCRIPTION
The Malfunction Indicator Lamp (MIL) "Service Engine Soon" is located in the Instrument Panel Cluster (IPC). The MIL (Service Engine Soon) is controlled through CKT 419 by the Powertrain Control Module (PCM).The MIL is used to indicate that a system malfunction has occurred. Under normal operation, the MIL will illuminate for less than one second and then remain "OFF".

CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. With CKT 419 jumpered directly to ground, the MIL (Service Engine Soon) should be "ON". If not, CKT 419 or CKT 39 is open, or the bulb or cluster is bad.
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 Terminal End View" in front of this section for PCM pin locations of ground circuits.

DIAGNOSTIC AIDS
Engine runs OK, check:
- Faulty light bulb.
- CKT 419 open or CKT 39 open.
- 10 amp ignition #1 fuse open.
Engine cranks, but will not run:
- 15 amp fuel pump fuse or CKT 1042 open to fuel pump micro relay.
- Ignition CKT 439 to PCM open.
- 10 amp PCM fuse open.
- Poor connection to PCM.