Chart A-1 No Malfunction Indicator Lamp (MIL)

Chart A1: No Malfunction Indicator Lamp (MIL):

Malfunction Indicator Lamp (MIL) Circuit.:

CIRCUIT DESCRIPTION
There should always be a steady MIL when the ignition is "ON" and engine stopped. Ignition voltage is supplied to the bulb on CKT 39. The Powertrain Control Module (PCM) will turn the light "ON" by providing the ground path through CKT 419.

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

1. Fuse # 2 and # 5 feed several circuits in addition to the PCM. Check thoroughly for a short to ground or a shorted component that may cause either fuse to open.
2. Low voltage on "D3" will cause a high idle and soft landing to 3rd gear. If the voltage is extremely low, the MIL may not operate and/or serial data may be lost. If serial data appears to be functioning, cycle the ignition "OFF/ON" and recheck.

DIAGNOSTIC AIDS
An open circuit to "D3" will cause a high idle, no serial data and soft landing to 3rd gear.
An open circuit to "B3O" will cause a no start and no MIL. An open CKT 340 between the fuse and the splice will cause a no start and no MIL. "B15" and "B31" are connected internally within the PCM.