1 Drive vehicle until it reaches operating temperature.
2 Stop the vehicle, place it in park or neutral and turn ignition OFF.
3 If the vehicle is not equipped with a dash-mounted CEL (Check Engine Light), connect an LED tester or Voltmeter between the battery (+, A) supply and the plug 2 terminal + (B) as shown.
4 Connect a switch to the connector plug 1 terminal - and plug 2 terminal as shown in the diagram.
5 Switch ignition on, Close the switch for at least 5 seconds. Open the switch, the Check Engine Light (CEL) or LED will begin to flash, or the Voltmeter reading will indicate voltage swings.
NOTE -Codes can only be retrieved one at a time, to read the next code operate switch for 5 seconds when the CodeReader prompts.
6 Read codes as described in the Code Format Description below.
7 Press the continue button to enter the code numbers and get the code description(s).