1 Drive vehicle until it reaches operating temperature.
2 Stop the vehicle, place it in park or neutral and turn ignition OFF.
NOTE -Models 80 (1.6L or 2.0L) and 100/A6 (2.0L) with Bosch Mono-Motronic MA1.2 or MA1.3 ECM's will require LED tester or Voltmeter connected to plug 1 (Black) terminal + and pin 33 (for 35 pin plug ECM) or pin 4 (for 45 pin plug ECM) on the back of the ECM plug.
5 Switch ignition to on position.
6 Operate switch for 4 to 6 seconds.
NOTE -Only one error code can be read at a time, to read the next code activate switch again.
7 Read codes as described in the Code Format Description below.
8 Press the continue button to enter the code numbers and get the code description(s).