Engine Control Module: Testing and Inspection

6 Cylinder & V8 Engines
1. With engine at normal operating temperature, make sure carburetor switch is not grounded.
2. Connect a tachometer to engine and increase engine speed to 1500 RPM.
3. Connect a voltmeter to green solenoid output wire going to carburetor. Do not separate connector from wiring harness. Separate connector at oxygen sensor and connect a jumper wire to harness end.
4. Connect other end of jumper wire to a good ground. Engine speed should increase a minimum of 50 RPM and voltmeter should indicate more than 9 volts.
5. Hold wire with one hand and with the other hand touch the battery positive terminal. Engine speed should decrease at least 50 RPM and voltmeter should indicate less than 3 volts.
6. If computer fails tests in steps 4 and 5, replace it.