Diagnostic tool
The software has been subdivided. For Saab 900 and 9000 (version 44.000 and later) a 10 Mbyte memory card is used. For 9-5, 9-3, 9-3 Sport Saloon and SPS (version 102.000) a 32 Mbyte memory card is required. The subdivision gives assured functionality for systems in older cars and less validation work with new releases. Both cards can sit in the diagnostic tool. You switch between cards by starting the diagnostic tool, waiting until the introduction screen is shown and then pressing
- Shift
- Left arrow or right arrow
- Shift
For 9-3 Sport Saloon (9440), connect the P-bus and I-bus are directly connected to the data link connector, which requires use of an adapter (CANdi) for the diagnostic tool. The increased complexity of the car has increased the demands on the diagnostic tool. The diagnostic tool has therefore been adapted more directly to various user situations. When Tech2 is used for car models other than the 9-3 Sport Saloon and 9-5 prior to MY06, the CANdi box must not be used.
Diagnostic Strategy
The diagnostic strategy remains unchanged. You first read the diagnostic trouble codes from all the control modules and then perform fault diagnosis on the diagnostic trouble codes whose symptom description corresponds with the customer complaint. The difference in the diagnostic tool is that you now always read the diagnostic trouble codes from all control modules one at a time. You can then choose to transfer the diagnostic trouble codes to WIS via an RS 232 cable or enter them by hand. The diagnostic trouble codes now have two extra characters to point out the type of fault more accurately.
To easily find the activations or read values used in fault diagnosis for a specific trouble code you can select, "Diagnostic Data, trouble code" and then see directly just the values used in WIS fault diagnosis.
Fault Diagnosis By Symptom
Using fault diagnosis by symptom is more difficult to determine in advance which control module should be contacted to read values or activate. Accordingly the diagnostic tool has been divided into operations. You no longer contact a control module but an operation, that is a virtual control module. This means that with a fault on e.g. the left flashers you do not need to think about which control module is involved in the operation, you just select "Left flashers" from the menu. The diagnostic tool will then present the values and activations from all control modules involved in the left flashers operation. If you find something wrong, you can then see which control module the value came from and then perform fault diagnosis using, e.g. the wiring diagram.
During fault diagnosis on a specific operation using the diagnostic tool information about this can be found in WIS. In WIS there is an extra search window that uses the same navigation as on the diagnostic tool.
To bear in mind in respect of On Board Diagnostics
- Not all faults that arise can be identified. Even if there is no electronic fault for an injector, it does not necessarily mean that it is injecting petrol as it is supposed to. It only indicates that the circuit is OK.
- In general, digital inputs have no or poor diagnostics. Use the diagnostic tool to check the read values.
- In general, analog inputs have good diagnostics. One knows that the circuit is OK if no diagnostic trouble code is set. One cannot, however, be sure that the value is correct. The fact that no diagnostic trouble code is set can be misleading. Use the diagnostic tool to check the read values.
- Outputs generally have good diagnostics. You can be fairly certain that the circuit is unbroken if no diagnostic trouble code is set, but despite this you cannot know whether the device is doing its job. Use the diagnostic tool to activate it and check that it is working.
Relays are sometimes involved. The control module is only able to check that everything is OK in its own circuit, i.e. via the relay winding. This tells you nothing about how the fuel pump or radiator fan is working.