Ignition Switch: Testing and Inspection

The Ignition Switch allows current to the starting circuit and ECU pin 55 when the Inhibitor Switch is positioned in Neutral or Park. Based on this signal, the ECU controls the fuel and ignition for starting and monitors the engine speed signal. When engine speed is reduced at idle due to transmission load, the ECU operates the Idle Speed Control (ISC) servo to maintain the optimum idle speed.

ECU Pin Connectors:

To test the start circuit, locate ECU pin 55 and test for system voltage while cranking the engine.

If the test proves to be unsatisfactory, test the circuit from the ignition switch to the ECU for continuity. Repair or replace the harness as necessary if required.

If the same problem reoccurs, it is possible that there is an intermittent failure of the component or the ECU. Check for looseness at all harness junctions and test for an intermittent failure.