Diagnostic Tips

Remember when fault diagnosing that:

1. The data link connector is located under the fascia by the steering wheel column. See Fig 1 .
   Fig 1: Locating Data Link Connector

   Courtesy of SAAB-SCANIA OF AMERICA, INC.
2. During diagnosis the ignition switch should always be in drive position.
3. Read and make note of stored diagnostic trouble codes in all systems before the battery and any electronic control modules are disconnected.
4. Also check that voltage and correct ground are available in the data link connector and that the connector's pins are undamaged and securely fitted.
5. To avoid damage to the electronic control module/components always check that the ignition is switched off before the connector(s) is/are unplugged.
6. Always check that the electronic control module's ground connections and supply voltages are correct.
7. It may sometimes be necessary to release connectors and check that terminals and pins are undamaged and securely fitted. Refit connectors and clear all diagnostic trouble codes. If possible, start/run the car and check if the fault(s) are still there.
8. All signals around the 12 volt level are proportional to the battery voltage and the levels should thus only be used as a guide.
9. The 0 volt signals indicate ground but could on a sensitive multimeter give an indication of a measurable voltage.
10. Never switch from one unit to another (for example from V via I to Ohm) on the measuring instrument without first having unplugged the instrument's cables.