Discovery II
INSTRUMENTS
DESCRIPTION AND OPERATION
88-25
Supplementary Restraint System (SRS) warning lamp
The SRS warning lamp within the instrument pack utilises a red LED and a clear legend. If a fault within the SRS is
detected, the SRS DCU illuminates the LED, providing the driver with a visible warning.
When the ignition is switched on, the SRS DCU illuminates the LED to provide a self-check, providing there is no fault
it will remain illuminated for 3 seconds or until the ignition is switched off. The SRS warning lamp does not output fault
codes.
The power input for the LED is supplied by the instrument pack via fuse 35. The SRS DCU provides the earth path to
illuminate the SRS warning lamp during the 3 second self-check.
The SRS warning lamp is switched on continuously by the instrument pack if the SRS DCU supply voltage is less than
half of the ignition switch voltage, with a tolerance of +2 or -1 volt.
The SRS warning lamp is operated by the SRS DCU if a fault is detected within the supplementary restraint system
circuits. The warning lamp is switched on according to the voltage present in the SRS DCU to instrument pack earth
path as follows:
l
< 1.8 volts = warning lamp on.
l
> 7.7 volts = warning lamp off.
