Chart A1-2 Malfunction Indicator Lamp ON Steady

Diagnostic Chart:

Malfunction Indicator Lamp Circuit:

CIRCUIT DESCRIPTION
The Malfunction Indicator Lamp (MIL) will flash diagnostic trouble codes when either the diagnostic request terminal in the duty check Data Link Connector (DLC) or the DIAG SW connector in the junction block is grounded.

TEST DESCRIPTION
Numbers below refer to circled numbers on the diagnostic chart.

1. This will check for a grounded indicator circuit.
2. This will determine if it is an open diagnostic request terminal circuit or a faulty Engine Control Module (ECM).