Component Tests and General Diagnostics

Air Flow Meter Location:

1. Disconnect the harness connector from the air flow meter.

Injection Electronics (Motronic Control Unit). Wiring Diagram:

2. With the ignition switch in the run (ON) position measure the following voltages at the female connector.

^ Gray wire (terminal 3) and ground = Approx. 5 volts
^ Gray and gray/yellow wire (terminals 3 and 2) = Approx. 5 volts
^ Gray and gray/blue wire (terminals 3 and 4) = Approx. 5 volts

3. If any voltage is incorrect, check and repair associated connections and wires for opens and shorts to voltage and ground.

^ If wires and connections are OK, replace the DME control unit.

4. If all voltages are correct check for continuity between the following terminals at the air flow meter connector (male plug). Measure between pins:

^ 7 and 26 = Continuity
^ 7 and 12 = Continuity


^ If any results are incorrect, replace the air flow meter.
^ If all results are correct, proceed to step 5.

5. Reconnect the harness connector and remove cover from rear of connector.
6. Measure the voltage between gray/yellow wire (terminal 2) and ground while moving the intake air flap manually.

^ If voltage varies between approximately 0.5 and 4.5 volts, check or repair wire to terminal 7 of DME control unit harness connector for an open circuit. If wire is OK, replace the DME control unit.
^ If the voltage does not vary between 0.5 and 4.5 volts, check or repair wire to terminal 7 of DME control unit harness connector for short to ground. If wiring is OK, repair or replace the air flow meter.