Chart A-2 Service Engine Soon Light ON Steady

Chart A-2:

ECM Wiring Diagram:

CIRCUIT DESCRIPTION:

There should always be a steady "CHECK ENGINE" light when the ignition switch is "ON." With check connector terminal grounded The "CHECK ENGINE" light will flash "ON" and "OFF" rapidly, or will flash any trouble codes that are in the ECMs memory. A steady "CHECK ENGINE" light suggests a short to ground or an open Diagnosis Switch circuit terminal.

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

1. This will check for a grounded light circuit.

2. This will determine if it is an open Diagnosis Switch terminal circuit or a faulty ECM.