ECU LAND ROVER DISCOVERY 2002 Workshop Manual

INSTRUMENTS
88-22 DESCRIPTION AND OPERATION
Brake system warning lamp
The brake system warning lamp within the instrument pack utilises a red LED and a clear legend. If the brake fluid
level is low, the hand brake is operated or there is a brake system fault, the LED will be illuminated providing the driver
with a visible warning.
When the ignition is switched on, the instrument pack 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.
There are two configurations of the legend for the warning lamp:
lNAS only.
lAll other markets.
The power input for the LED is supplied by the instrument pack via fuse 27. The hand brake switch, the low brake fluid
level switch or the SLABS ECU provides the earth path illuminating the warning lamp.
The hand brake switch has a separate connection to the vehicle body. The low brake fluid switch connects to an earth
header joint.
On the earth paths to the instrument pack the warning lamp is controlled according to these voltages:
l< 1.8 volts = warning lamp on.
l> 7.7 volts = warning lamp off.

INSTRUMENTS
88-24 DESCRIPTION AND OPERATION
Traction control warning lamp
The traction control warning lamp within the instrument pack utilises a red LED and a clear legend. The traction control
warning lamp informs the driver that the traction control system is enabled. The warning lamp is hard wired to the
SLABS ECU. The SLABS ECU controls the warning lamp on or off via a high or low voltage signal to the instrument
pack.
When the ignition is switched on, the SLABS ECU 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 power input for the LED is supplied by the instrument pack via fuse 27. The SLABS ECU provides the earth path
to illuminate the warning lamp.
The voltage on the SLABS ECU earth path to the instrument pack is as follows:
l< 1.8 volts = warning lamp on.
l> 7.7 volts = warning lamp off.

INSTRUMENTS
88-26 DESCRIPTION AND OPERATION
Off road mode warning lamp
The off road mode warning lamp is available on vehicles equipped with self levelling suspension. The off road mode
warning lamp within the instrument pack utilises an amber LED and a clear legend. On vehicles fitted with self levelling
suspension the driver can enable the function using the off road mode fascia switch.
The SLABS ECU illuminates the LED, providing the driver with a visible warning.
When the ignition is switched on the SLABS ECU 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 off road mode is only enabled if the transfer box is in low range.
The off road mode warning lamp will flash at the rate of 2 Hz during the transition phase (up and down), and is
illuminated continuously when at full height.
The vehicle may be parked in off road mode the driver is reminded when the ignition is switched on that off road mode
is still active by the warning lamp flashing twice at a ratio 2 Hz then illuminates continuously.
The warning lamp will flash at 2 Hz in belly out mode. Belly out mode is if the vehicle grounds out, then the suspension
will raise to try and clear the underside of the vehicle.
If a new SLABS ECU is fitted the warning lamp remains illuminated until the ECU has been calibrated using TestBook.
The warning lamp will illuminate continuously if the voltage supply is less than 10 volts for 1 second.
The power input for the LED is supplied by the instrument pack via fuse 27. The warning lamp is switched on
according to the voltage present in the SLABS ECU to instrument pack earth path as follows:
l< 1.8 volts = warning lamp on.
l> 7.7 volts = warning lamp off.

INSTRUMENTS
DESCRIPTION AND OPERATION 88-35
Hill Descent Control (HDC) fault warning lamp
The HDC fault warning lamp within the instrument pack utilises an amber LED and a clear legend. On vehicles fitted
with hill descent control the SLABS ECU illuminates the LED if a fault within the HDC system is detected, providing
the driver with a visible warning.
When the ignition is switched on, the SLABS ECU illuminates the LED to provide a self-check, it will remain illuminated
for 3 seconds or until the ignition is switched off, providing there is no fault.
The power input for the LED is supplied by the instrument pack via fuse 27. The SLABS ECU provides the earth path
to illuminate the HDC fault warning lamp
The voltage on the earth path from the SLABS ECU to the instrument pack has the following functions:
l< 1.8 volts = warning lamp is switched on.
l> 7.7 volts = warning lamp is switched off.

INSTRUMENTS
88-36 DESCRIPTION AND OPERATION
Self Levelling Suspension (SLS) warning lamp
The SLS warning lamp within the instrument pack utilises an amber LED and a clear legend. The SLABS ECU
illuminates the LED continuously if a fault within the SLS is detected, providing the driver with a visible warning.
When the ignition is switched on the SLABS ECU 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.
On vehicles equipped with coil springs the SLS warning lamp is extinguished after 850 milliseconds if the SLABS ECU
configuration of the vehicle is correct.
The SLS warning lamp flashes at 2 Hz when the remote handset control is used to raise or lower the ride height.
If a new SLABS ECU is installed the SLS warning lamp will remain illuminated until the ECU has been calibrated by
TestBook.
The warning lamp will illuminate continuously when battery voltage is less than 10 volts for greater than 1 second.
When the vehicle is in transportation mode the SLS warning lamp is illuminated continuously with ignition on, and will
flash at 2 Hz frequency as the vehicle rises from bump stop level to transport level on engine start.
The power input for the LED is supplied by the instrument pack via fuse 27. The SLABS ECU provides the earth path
to illuminate the warning lamp.
The voltage on the earth path from the SLABS ECU to the instrument pack has the following functions:
l< 1.8 volts = warning lamp on.
l> 7.7 volts = warning lamp off.

INSTRUMENTS
DESCRIPTION AND OPERATION 88-37
Active Cornering Enhancement (ACE) warning lamp
On vehicles fitted with ACE an LED within the instrument pack is used to alert the driver that the ACE ECU has
detected a fault in the system, providing the driver with a visible warning. The ACE warning lamp utilises an amber
LED and a clear legend.
When the ignition is switched on the ACE ECU 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 power input for the LED is supplied by the instrument pack via fuse 13. The ACE ECU provides the earth path to
illuminate the warning lamp.
The voltage on the earth path from the ACE ECU to the instrument pack has the following functions:
l< 1.8 volts = warning lamp on.
l> 7.7 volts = warning lamp off.

INSTRUMENTS
88-38 DESCRIPTION AND OPERATION
Gearbox manual/sport mode warning lamps
The gearbox manual/sport mode warning lamps within the instrument pack each utilise a green LED and a clear
legend. On vehicles fitted with an automatic gearbox, operating the manual mode switch instructs the Electronic
Automatic Transmission (EAT) ECU to illuminate the manual mode LED. Operating the sport mode switch instructs
the EAT ECU to illuminate the sport mode LED.
There is no self-test performed at ignition on for this warning lamp.
If the EAT ECU detects a fault it will cause both warning lamps to flash.
The power input for the LED's is supplied by the instrument pack. The EAT ECU applies a high or low voltage to the
instrument pack microprocessor which measures the applied voltage from the ECU and illuminates the appropriate
warning lamp.
The voltage on the earth paths from the EAT ECU to the instrument pack has the following functions:
Warning lamp response Manual earth path, volts Sport earth path, volts
No lamps > 7.7 > 7.7
Sport warning > 7.7 < 1.8
Manual warning < 1.8 > 7.7
Both lamps flash < 1.8 < 1.8

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
88-40 DESCRIPTION AND OPERATION
Audible warning speaker
The audible warning speaker is integral with the instrument pack and provides an audible warning to alert the driver
of the following situations:
lSeat belt warning lamp.
lKey in/lights on warning.
lSLABS command received warning.
lTransfer box in neutral warning.
lLights on warning.
It has a maximum pressure level of 87 dB at 1 metre (3.3 ft). The audible warning speaker is located on the rear of
the instrument pack.
The power input for the audible warning speaker is supplied by the instrument pack via fuse 27.
The BCU provides the earth paths for the following:
lThe seatbelt warning.
lKey in/lights on warning.
lLights on warning.
The SLABS ECU provides the earth paths for the SLABS commands. The EAT ECU provides the earth path for the
transfer box in neutral warning.
The BCU activates the audible warning speaker to produce audible warnings.
The audible warning speaker can operate with the ignition off.
The seatbelt warning will commence at key on, and in the event of a serial link failure, will terminate after 6 seconds.
The SLABS warnings are sounded only once for each received command.
The lights on warning and transfer box in neutral are sounded continuously until a sound off command is received.
Sound request number Sound functions Priority (1 = lowest, 6 = highest)
0Off 1
1 Seat belt warning 6
2 Key-in warning 3
3 SLABS/ HDC warning 4
4 Transfer box in neutral warning 5
5 Lights on warning 2

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