ecm LAND ROVER DISCOVERY 2002 Workshop Manual

INSTRUMENTS
88-28 DESCRIPTION AND OPERATION
Glow plug warning lamp
The glow plug warning lamp within the instrument pack utilises an amber LED and a clear legend. On vehicles with
diesel engines the LED illuminates when the ECM operates the glow plugs. After a predetermined time calculated by
the ECM, dependent on engine temperature, the LED is switched off providing the driver with a visible warning that
the engine can be started.
The power input for the LED is supplied by the instrument pack via fuse 27. The ECM provides the earth path to
illuminate the warning lamp.
The voltage on the earth path from the ECM to the instrument pack is as follows:
l< 1.8 volts = warning lamp on.
l> 7.7 volts = warning lamp off.

INSTRUMENTS
DESCRIPTION AND OPERATION 88-39
Anti-theft status warning lamp
The anti-theft status warning lamp within the instrument pack utilises a red LED and a clear legend.
The BCU illuminates the LED when the vehicle anti-theft system is active.
This provides a warning to potential thieves that the vehicle is protected by a security system.
When the ignition is switched on, the ECM illuminates the LED to provide a self-check, providing there is no fault it
will remain illuminated until the engine is started or the ignition is switched off.
The power input for the LED is supplied by the instrument pack via fuse 13. The BCU controls the earth path to
illuminate the warning lamp.
The voltage on the earth path from the BCU to the instrument pack will be less than 1 volt when the anti-theft status
is enabled.

INSTRUMENTS
DESCRIPTION AND OPERATION 88-41
Diagnostic connector
RHD illustrated
The diagnostic connector allows TestBook to communicate with the vehicle electrical system.
The modules that TestBook can interface with via the diagnostic connector are:
lSLABS ECU.
lBCU.
lECM (V8 and Td5).
lIDM.
lACE ECU.
lEAT ECU.
lSRS DCU.
TestBook communicates with the ECM, ECU's and the instrument pack for diagnostic purposes and for configuration
for a specific options or market. If communications on the diagnostic connector fail for greater than three seconds after
the ignition is in position II the gear selected display in the LCD flashes. This applies to both manual and automatic
vehicles in all markets.
The instrument pack options configured by TestBook are:
lAutomatic or manual gearbox fitted.
lDiesel or V8 engine fitted.
lACE fitted.
lSLS fitted.
lGulf, Japan or ROW markets.
lService engine reset.
lOdometer reset.
lHDC fitted.
lTraction control fitted.
The serial communications link is a bi-directional communications network providing both input and output on the
same pin.
M86 4705