SAAB WIS ONLINE

Self-diagnostics

Self-diagnostics


When the ignition is switched on and the system is under power, the control module starts its first self-test for a maximum of 10 seconds. As a safety precaution, the airbags cannot be triggered during that time.

The electric detonators, wiring harness, supply current, SRS lamps and processor are checked during the self-test.

The SRS lamps come on for 3-4 seconds during the first test when power is switched on to check the lamps.

The self-test is then carried out continuously for as long as power remains turned on. The system is then in normal working condition and can detect the beginning of a collision. In the event of a fault the SRS lamp flashes for 5 minutes and then remains on continuously. On cars with a central warning lamp, this lamp will come on and remain on from the moment a fault is detected.

Important

When the ignition is switched on: No airbag function for a maximum of 10 seconds. Certain faults can take up to 40 seconds to detect and the same time is taken to activate the warning lamps.


When a fault is recorded for the first time a diagnostic trouble code is generated. The code is the same, regardless of whether the fault is permanent or intermittent. At the same time as the diagnostic trouble code is generated, a fault counter and fault time counter start.

The fault counter counts how many times a particular fault is registered, up to 255 times. The fault time counter shows how long a permanent fault has been registered, or alternatively how much time has elapsed since an intermittent fault was first registered. The fault time counter counts in intervals of five minutes of charged time. The first interval is however two and one half minutes long so that even faults registered after a short time driving can be included.

The control module can save up to five different diagnostic trouble codes. After this, only diagnostic trouble code B1615 (ignition circuit activated) will be recorded and the last of the other five codes recorded will be deleted.

When the feed voltage is cut it takes a maximum of 5 seconds for the processor to disconnect the energy reserve from the detonator circuits.

The control module is of disposable type; once it has triggered the airbags it cannot be used again. If this has happened the SRS lamp will continue to flash even after 5 minutes has elapsed.

Readings of diagnostic trouble codes can be obtained after the airbags have been triggered but the codes cannot be cleared.