System Testing Precautions

- Do not disconnect or connect electrical connectors with the ignition switch in the ON position--unless specifically instructed by procedure.

- Do not connect test equipment directly to the ECM--except where noted.

- When measuring voltages at control module harness connectors, disconnect the harness connector with the ignition OFF, then turn the ignition ON as necessary.

- To prevent deforming the control unit harness connectors, do not probe terminals directly.
-- Insert pin(S) from the harness side and perform measurements through pin(S).

- Do not attempt to measure oxygen sensor output.
-- Doing so may damage the sensor.

- Do not probe wires through insulation
-- Damaged insulation can lead to corrosion of the wire causing system failure.