Handbrake Warning Lamp

Fault symptoms
The lamp does not light up when the handbrake is applied.

The central warning lamp does not light up when the speed of the car exceeds 5 km/h with the handbrake applied.

Diagnostic procedure
1 If only the central warning lamp lights up the indicator lamp bulb is faulty and must be changed.

If neither of the lamps light up, continue with point 2.
2 Connect an Intellegent Saab Tester (ISAT) Scan Tool and select "READ VALUES" followed by "WARNING INPUTS" and "HANDBRAKE".
3 If in proper working order, the Scan Tool's display should read "HANDBRAKE ON" when the handbrake is applied and "HANDBRAKE OFF" when it is not applied.

If this is the case, the bulb is probably faulty and must be changed.

If the lamp still fails to light up when activated, check that the new bulb is OK by fitting it in place of another bulb in the main instrument display panel that does light up.

If the bulb is intact, continue with point 7.

If "HANDBRAKE OFF" is displayed in both cases, there is a fault in the connection from the handbrake warning lamp switch. Continue with point 4.
4 Check the handbrake warning light switch visually to make sure that it is correctly fitted and that the contacts close when the switch is extended.







5 Check the wiring between the main instrument display panel and the handbrake switch by connecting a BOB to the 56-pin connector behind the main instrument display panel (which should be connected).

Handbrake applied.
6 Check for an open circuit by taking a reading across pin 1 on the BOB and a good grounding point.

The resistance reading obtained should be < 1 ohm.

If the wiring is not OK, investigate the cause and take appropriate action.

If the wiring is OK, the fault is probably in the main instrument display panel's processor card. Ground pin 1 on the BOB. If the warning lamp does not light up, continue in "Before Control Module Replacement".
7 The fault could be in the main instrument display panel. Remove the main instrument display panel's rear section complete with processor card and check that all leads between the processor card and the intermediate part are securely located.

If any lead has worked loose or is broken, continue in "Before Control Module Replacement".

If the wiring is OK, the fault is probably in the intermediate part with the lamp bulbs.