Instruments Land Rover Discovery L318

Scheme 1

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Scheme 4

General

The instrument pack consists of four analogue dials, four warning lamp packs and a Liquid Crystal Display (LCD) odometer.

The four dials are used to indicate

1. Road speed.
2. Engine speed.
3. Fuel tank level.
4. Engine coolant temperature.

The dials are driven by a microprocessor from information received from the serial communication link. Information input is received as either

1. Digital.
2. Analogue.
3. Pulse train.
4. Pulse Width Modulation (PWM).

The LCD provides information for

1. Odometer.
2. Trip distance.
3. Selected gear (on vehicles fitted with an automatic gearbox).

A trip reset button is provided to zero the trip display, this button also allows the selection of "miles" or "kilometers" for the display. A photocell controls the illumination of the LCD, maintaining contrast of the display during ambient light changes.

Within the four warning lamp packs there are 28 lamps. A long life bulb illuminates the high beam warning lamp and the rest of the warning lamps are illuminated by Light Emitting Diodes (LED's). All warning lamp legends are invisible until lit. When lit the symbols are illuminated on a black background.

The warning lamps illuminate in one of four colors. The color indicates the level of importance to the driver, as follows

1. Red = warning.
2. Amber = caution.
3. Green = system operative.
4. Blue = main beam operative.

The first warning lamp pack is located in the top left-hand side of the instrument pack and contains the following warning lamps

1. Traction control warning lamp.
2. Transfer box in neutral warning lamp.
3. Differential lock warning lamp
4. Overspeed warning lamp (activated for gulf market only).
5. Brake system warning lamp.
6. Hill Descent Control (HDC) information warning lamp.
7. Malfunction Indicator Lamp (MIL)/ SERVICE ENGINE SOON warning lamp.

The second warning lamp pack is located in the center of the instrument pack and contains the following warning lamps

1. Direction indicator warning lamps.
2. High beam warning lamp.
3. Anti-lock brake system warning lamp.

The third warning lamp pack is located in the top right-hand side of the instrument pack and contains the following warning lamps

1. SRS warning lamp.
2. SLS off road mode warning lamp.
3. Trailer warning lamp.
4. Glow plug warning lamp.
5. Water in fuel filter warning lamp.
6. Seat belt warning lamp.
7. Transmission high temperature warning lamp.

The fourth warning lamp pack is located underneath the tachometer of the instrument pack contains the following warning lamps

1. Oil pressure warning lamp.
2. Alternator charge warning lamp.
3. HDC fault warning lamp.
4. Self Levelling Suspension (SLS) warning lamp.
5. Active Cornering Enhancement (ACE) warning lamp.
6. Gearbox manual/sport mode warning lamps.

The serial communication link is used to allow information to travel to and from the instrument pack, and it provides the ability to configure the instrument pack to a specific market. It also allows the instrument pack to be controlled by TestBook for diagnostics.

There are five market specific variants of the instrument pack

1. United Kingdom (UK).
2. North American Specification (NAS).
3. Canada.
4. Australia.
5. Rest Of the World (ROW), Gulf and Japan.

The main difference between the five markets is that the speedometer will indicate road speed in mph as major figures and km/h as minor figures, km/h as major figures and mph as minor figures or km/h only.

When TestBook is used to diagnose the instrument pack it demands each of the dials and warning lamps to operate in-turn so a visual check of their operation can be made.

Speedometer

The speedometer informs the driver of the current vehicle road speed. It has a Liquid Crystal Display (LCD) to show odometer, trip meter and, on automatic gearbox models, the selected gear. The speedometer will not show speeds of less than 1.5 mph (2.5 km/h).

There are three different market configurations

1. NAS and UK = mph as major figures km/h as minor figures.
2. Canada = km/h as major figures mph as minor figures.
3. ROW and Australia = km/h only.

The Self Levelling and Anti-Lock Brake System (SLABS) ECU provides the signal input for the road speed. The signal is at 8000 pulses per mile (1.6 kilometers).

Scheme 5

The LCD has 3 different display elements

1. Odometer.
2. Trip meter.
3. Selected gear (on vehicles with automatic gearboxes).

The odometer displays units in either miles or kilometers. It has a range from 0 to 999,999 units, only full units are displayed irrespective of the type of units selected, the display will stop at 999,999 units. TestBook can be used to reset the odometer. This is allowed only once and must be carried out before 150 miles (240 km) from new, after this distance the feature is disabled. The odometer may lose up to one km (0.6 miles) when the battery is reconnected, this is due to the software incorporated into the instrument pack to prevent anyone tampering with the odometer reading.

The trip meter displays units in either miles or kilometers and has a range of 0.0 to 999.9 units. The display rolls over from 999.9 to 0.0 units. Units down to one tenth of a mile or one tenth of a kilometer are displayed. The trip meter displays 0.0 when the battery is reconnected or charged from a discharged state.

A push button located next to the LCD is utilized to reset the trip meter to zero and to change the units from miles to kilometers. Pressing the button for less than 2 seconds allows the display to reset to zero. Pressing the button for more than 2 seconds changes the units from miles to kilometers and vice versa. The units will only change for UK, NAS and Canadian market vehicles.

The selected gear displays when the automatic gearbox is in park, reverse, neutral, drive 3,2,1, by using the letters or numbers PRND321 in the display.

The data input for the LCD odometer/trip meter is from the SLABS ECU for the distance input and from the BCU for the gear position. The instrument pack provides the earth path to illuminate the gear position warning lamp.

If a replacement instrument pack is required TestBook must be used to retrieve the odometer reading, so that when the new instrument pack is fitted the odometer reading can be programmed in.

Scheme 6

The tachometer is an integral part of the instrument pack. Located next to the speedometer. it displays engine speed in revolutions per minute. It is an analogue gauge with a maximum reading of 6000 rev/min.

V8 and diesel variants use the same gauge.

The input for the tachometer is from the ECM. It is a digital signal at 2 pulses per engine revolution. When the ignition is switched on with the engine not running, the ECM will generates pulses equivalent to 228 rev/min for diagnostic purposes. The tachometer will not register a reading, as it only indicate engine speeds above 228 rev/min.

Scheme 7

The fuel gauge is an analogue gauge that indicates the level of fuel in the fuel tank with the ignition on. The fuel gauge returns to 0 with ignition off. The gauge reading is proportional to the level of fuel in the tank. It is a damped action gauge to prevent erroneous readings caused by fuel moving in the tank. The damping action is minimized when the ignition is switched on to give an accurate reading within 2.5 seconds.

The signal input for the fuel gauge is from the tank sender unit, it is a variable voltage signal proportional to the level of fuel in the tank. The instrument pack provides the power via fuse 27 to the fuel gauge, then from the gauge on to the fuel tank sender unit. The earth path return circuit of the sender unit is connected to the instrument pack.

A low fuel level signal is provided for the ECM when the sender resistance is greater than 158n8 ohms, this is used to create a fault code indicating low fuel level during misfire diagnosis using TestBook.

Scheme 8

The fuel tank sender unit is combined with the pump. It contains a variable resistor with change in resistance proportional to the change in level of fuel in the tank.

The resistance of the fuel tank sender unit in relation to tank contents and gauge display is shown in the table below

FUEL TANK SENDER UNIT RESISTANCE SPECIFICATIONS

The fuel tank sender unit input voltage feed is supplied from the fuel gauge. The earth path return circuit of the sender unit is connected to the instrument pack.

Scheme 9

The engine coolant temperature gauge is an analogue gauge with three sections: cold temperature; normal operating temperature; high temperature. Under normal engine operating temperatures the engine coolant temperature gauge will display in the center of the gauge. When the engine is cold e.g. from first start-up, the coolant temperature gauge will display in the cold band. When the engine is over heating the temperature gauge will display in the high temperature band. If the engine coolant temperature gauge receives no input or the input is out of range the temperature gauge will read cold and the high coolant temperature warning lamp will be illuminated.

The input signal is a PWM signal from the engine coolant temperature sensor via the ECM. The power input for the high coolant temperature warning lamp is supplied by the instrument pack via fuse 27. The ECM controls the earth path to illuminate the high coolant temperature warning lamp.

Scheme 10

The MIL/service engine soon warning lamp within the instrument pack utilizes an amber LED and a clear legend. If an emission related fault is detected by the engine management system or, on automatic gearbox models, the EAT ECU, the ECM will illuminate the LED providing the driver with a visible warning.

The warning lamp will illuminate whenever the vehicle is driven until the fault is repaired, and the ECM fault code memory is cleared using TestBook.

When the ignition is switch on the ECM carries out a self-test function of the lamp. The lamp will illuminate for 3 seconds then extinguish if no faults exist. If a fault is present the lamp will be extinguished for 1 second before illuminating again to indicate a fault exists.

There are two configurations of the legend for the warning lamp

1. NAS and Canada = SERVICE ENGINE SOON text.
2. All other markets = MIL SAE J1930 symbol.

The power input for the LED is supplied by the instrument pack via fuse 27. The ECM provides a voltage to the instrument pack Central Processing Unit (CPU) to control the warning lamp

1. < 1.8 volts = warning lamp on.
2. > 7.7 volts = warning lamp off.

Scheme 11

The transfer box neutral warning lamp illuminates to inform the driver that the transfer box is in neutral. The warning lamp utilizes an amber LED with a clear legend which is to ISO design standards. There is no self-check for this warning lamp. If the transfer box neutral warning lamp is illuminated the audible warning speaker will also chime.

There are two configurations for this warning lamp

1. NAS, Canada and Japan = warning lamp enabled.
2. Rest of World = warning lamp disabled.

The instrument pack provides the power input and the BCU provides the signal to illuminate the warning lamp. The transfer box in neutral information is provided by a switch on the transfer box, this sends an analogue signal to the BCU. The BCU commands the warning lamp on using the serial link to the instrument pack.

Scheme 12

The overspeed warning lamp within the instrument pack utilizes an amber LED and a clear legend. The BCU illuminates the LED when the vehicle speed has exceeded 77 mph (123 km/h) and remains on until the vehicle speed falls below 74 mph (118 km/h), providing the driver with a visible warning. There is no self-check for this warning lamp.

There are two configurations for this warning lamp

1. Gulf = symbol.
2. All other markets = disabled.

The instrument pack provides the power input and the warning lamp is controlled by the instrument pack according to PWM signal received from the ECM. The road speed information is derived from the SLABS ECU.

The lamp activation thresholds are shown in the table below

LAMP ACTIVATION THRESHOLDS

Scheme 13

Dimmer switch

The instrument pack contains 3 bulbs to illuminate the dials. Depending on market the bulbs are illuminated either from the side lamps feed with no dimmer control or from a PWM dimmer control located on the dashboard. A PWM dimmer is used so finer control of the instrument illumination can be achieved.

The input is either direct from the side lamp power feed or from the PWM dimmer control. The instrument pack provides the earth path to illuminate the lamps.

Scheme 14

The direction indicator warning lamp within the instrument pack utilizes a green LED and a clear legend. The LED flashes at the same rate as the external indicators, providing the driver with a visible warning.

Operating the left-hand indicator switch instructs the BCU to activate the left-hand indicator warning lamp.

Operating the right indicator switch instructs the BCU to activate the right-hand indicator warning lamp.

There is no self-test performed at ignition on for these warning lamps.

The power input for the LED is supplied by the instrument pack via fuse 27. The earth path for the warning lamps is from the BCU.

Scheme 15

The main beam warning lamp within the instrument pack utilizes a clear 14 volt 2 watt long life bulb and a blue legend. The bulb illuminates when the headlamps are switched to main beam, providing the driver with a visible warning.

There is no self-test performed at ignition on for this warning lamp.

Operating the main beam switch provides the Intelligent Driver Module (IDM) with battery voltage. This feed activates the IDM to supply the power for the main beam warning lamp. The earth path is provided through the instrument pack.

Scheme 16

The ABS warning lamp within the instrument pack utilizes an amber LED with a clear legend. If a fault within the ABS is detected, 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. If an ABS fault is detected while driving the warning lamp will illuminate to alert the driver.

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 ABS warning lamp.

Scheme 17

The high engine coolant temperature warning lamp within the instrument pack utilizes a red LED and a clear legend. The ECM illuminates the LED when it detects the engine coolant has exceeded a temperature of 121 °C (250 °F) and switches it off when the coolant temperature drops below 118 °C (244 °F). The ECM also illuminates the high engine coolant temperature warning lamp when it detects the PWM duty cycle to the temperature gauge is out of range. If it is greater than 94% duty cycle when the engine is hot, or less than 8% duty cycle when the engine is cold, the engine coolant temperature gauge pointer will indicate cold, thus alerting the driver with an additional visible warning.

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 for 3 seconds or until the ignition is switched off.

The response of the engine high temperature warning lamp varies according to engine type and market, there are three conditions

1. V8 - Gulf.
2. V8 - all markets except Gulf.
3. Diesel - all markets.

The vehicle configuration determines which condition is set.

The PWM duty cycle thresholds for illuminating and extinguishing the warning lamp are given in the table below

PWM DUTY CYCLE THRESHOLDS

The power input for the LED is supplied by the instrument pack via fuse 27. The ECM controls the earth path to illuminate the warning lamp.

Scheme 18

The low fuel warning lamp within the instrument pack utilizes an amber LED and a clear legend. The ECM illuminates the LED when the fuel gauge pointer has reached 8 degrees from zero. The LED remains illuminated until fuel is added to move the fuel gauge pointer past 20 degrees from zero. This provides the driver with a visible warning that the fuel level in the tank is low.

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 for 3 seconds or until the ignition is switched off.

The sender unit resistance thresholds for switching the lamp on and off are shown in the table below

SENDER UNIT RESISTANCE THRESHOLDS

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.

Scheme 19

The HDC information warning lamp within the instrument pack utilizes a green LED and a clear legend. On vehicles fitted with HDC, the HDC switch provides a hard wired voltage to the SLABS ECU to illuminate the LED when HDC is switched on. This provides the driver with a visible warning that the system is enabled.

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

1. < 1.8 volts = warning lamp on.
2. > 7.7 volts = warning lamp off.

Scheme 20

The brake system warning lamp within the instrument pack utilizes 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

1. NAS only.
2. All 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

1. < 1.8 volts = warning lamp on.
2. > 7.7 volts = warning lamp off.

Scheme 21

The differential lock is a device used for rolling road testing only on vehicles up to 03 model year. On vehicles from 03 model year, the differential is a driver selectable option which can also be used for off road driving. Refer to ROLLING ROAD (DYNO) TESTING .

Differential lock warning lamp - vehicles up to 03 model year

The differential lock warning lamp within the instrument pack utilizes a red LED and a clear legend. When the differential lock is engaged, using the lever on the side of the transfer box, the differential lock switch is operated and the warning lamp is switched on providing the driver with a visible warning.

When the differential lock is engaged, the warning lamp will be illuminated continuously when the ignition switch is in position II.

Differential lock warning lamp - vehicles from 03 model year

The differential lock warning lamp is located in the top left hand corner of the instrument pack and uses an amber LED and a clear legend. When the differential lock is engaged, the warning lamp illuminates when the ignition is on to provide a visual indication to the driver that the differential lock is engaged. The instrument pack, simultaneously emits three audible warning chimes as a confirmation.

When the differential lock is disengaged, the warning lamp is extinguished and the instrument pack simultaneously emits three audible warning chimes as a confirmation.

All vehicles

The power input for the LED is supplied by the instrument pack via fuse 13 in the engine compartment fusebox. The differential lock switch or switches provide(s) the earth path illuminating the warning lamp.

The voltage on the differential lock switch or switches to instrument pack earth path produces the following warning lamp functions

1. < 1.8 volts = warning lamp on.
2. > 7.7 volts = warning lamp off.

Scheme 22

The traction control warning lamp within the instrument pack utilizes 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

1. < 1.8 volts = warning lamp on.
2. > 7.7 volts = warning lamp off.

Scheme 23

The SRS warning lamp within the instrument pack utilizes 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

1. < 1.8 volts = warning lamp on.
2. > 7.7 volts = warning lamp off.

Scheme 24

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 utilizes 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

1. < 1.8 volts = warning lamp on.
2. > 7.7 volts = warning lamp off.

Scheme 25

The trailer warning lamp within the instrument pack utilizes a green LED and a clear legend. When a trailer is fitted to the vehicle, and the direction indicators are operated, the BCU detects additional current draw and illuminates the LED, providing the driver with a visible warning.

When the ignition is switched on the BCU 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. This self-check is every time the ignition is switched on, not only if a trailer is connected.

The power input for the LED is supplied by the instrument pack via fuse 13. The BCU provides the earth path to illuminate the warning lamp.

Scheme 26

The glow plug warning lamp within the instrument pack utilizes 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

1. < 1.8 volts = warning lamp on.
2. > 7.7 volts = warning lamp off.

Scheme 27

The water in fuel filter warning lamp within the instrument pack utilizes an amber LED and a clear legend. On vehicles with diesel engines the LED is illuminated when the water sensor detects water is present in the fuel filter, 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 water present in the fuel filter 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 water sensor provides the earth path to illuminate the warning lamp. The voltage on the earth path from the sensor to the instrument pack is as follows

1. < 1.8 volts = warning lamp on.
2. > 7.7 volts = warning lamp off.

Scheme 28

On vehicles with diesel engines a water sensor is located in the bottom of the fuel filter. The sensor utilizes the different resistance properties between water and diesel fuel to determines the presence of water in the fuel.

The sensor receives a battery voltage supply from the fuel pump relay. The sensor output is supplied to the instrument pack. The water sensor provides the earth path to illuminate the warning lamp.

1. < 1.8 volts = warning lamp on.
2. > 7.7 volts = warning lamp off.

Scheme 29

The seat belt warning lamp within the instrument pack utilizes a red LED and a clear legend. The BCU utilizes a switch in each of the front seat belt buckles to determine if a seat belt is not fastened.

When the ignition is switched on, the BCU illuminates the LED for 6 seconds or until the BCU determines that a seat belt is fastened which extinguished the warning lamp. This provides the driver with a visible reminder that the seat belts are not fastened.

The instrument pack provides the self-check if the diagnostic connector fails.

The power input for the LED is supplied by the instrument pack via fuse 13. The BCU provides the earth path to illuminate the seat belt warning lamp.

The seat belt buckle switches complete the earth path in the BCU sensing circuit, the BCU commands the instrument pack to switch on the seat belt warning lamp.

The BCU earth path to the seat belt buckle is as follows

1. < 1.8 volts = warning lamp off.
2. > 7.7 volts = warning lamp off.

Scheme 30

The transmission high temperature warning lamp within the instrument pack utilizes a red LED and a clear legend. On vehicles fitted with automatic gearboxes, the transmission high temperature warning lamp is utilized to provide the driver with a visible warning that the automatic gearbox oil has exceeded a normal operating temperature. The warning lamp will extinguish if the gearbox oil returns back to normal operating temperature.

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.

The power input for the LED is supplied by the instrument pack via fuse 13. The temperature sensor provides the earth path to illuminate the transmission high temperature warning lamp.

The transmission high temperature warning lamp is controlled according to the voltage present on the temperature sensor to instrument panel earth path

1. < 1.8 volts = warning lamp on.
2. > 7.7 volts = warning lamp off.

Scheme 31

The engine oil pressure warning lamp within the instrument pack utilizes a red LED and a clear legend. The LED illuminates when the engine oil pressure is below the specified pressure (see table), providing the driver with a visible warning that the engine oil pressure has fallen below the specified minimum reading.

There is no self-test performed at ignition on for this warning lamp.

The power input for the LED is supplied by the instrument pack via fuse 27. The oil pressure switch located on the engine provides the earth path to illuminate the warning lamp, it will remain illuminated until the engine is started and the oil pressure exceeds the appropriate threshold and opens the switch contacts.

LOW OIL PRESSURE SWITCH OPERATING PRESSURE

The response to the voltage signal at the instrument pack is as follows

1. < 1.8 volts = warning lamp on.
2. > 7.7 volts = warning lamp off.

Scheme 32

The alternator charge warning lamp within the instrument pack utilizes a red LED and a clear legend. The LED illuminates when the alternator output voltage is less than 2 volts. When the alternator output is greater than 7.6 volts the LED is extinguished, providing the driver with a visible warning that the alternator is charging.

When the ignition is switched on, and the LED illuminates, it will remain illuminated until the engine is started and voltage is above the predetermined parameter, or 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 alternator provides a signal to illuminate the warning lamp by means of a hard wired connection to the instrument pack.

The response to the voltage signal at the instrument pack is as follows

1. < 2.0 volts = warning lamp on.
2. > 7.6 volts = warning lamp off.

Scheme 33

The HDC fault warning lamp within the instrument pack utilizes 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

1. < 1.8 volts = warning lamp is switched on.
2. > 7.7 volts = warning lamp is switched off.

Scheme 34

The SLS warning lamp within the instrument pack utilizes 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

1. < 1.8 volts = warning lamp on.
2. > 7.7 volts = warning lamp off.

Scheme 35

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 utilizes 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

1. < 1.8 volts = warning lamp on.
2. > 7.7 volts = warning lamp off.

Scheme 36

The gearbox manual/sport mode warning lamps within the instrument pack each utilize 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

EAT ECU TO INSTRUMENT PACK EARTH PATHS VOLTAGE

Scheme 37

The anti-theft status warning lamp within the instrument pack utilizes 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.

Scheme 38

The audible warning speaker is integral with the instrument pack and provides an audible warning to alert the driver of the following situations

1. Seat belt warning lamp.
2. Key in/lights on warning.
3. SLABS command received warning.
4. Transfer box in neutral warning.
5. Lights on warning.

It has a maximum pressure level of 87 dB at 1 meter (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

1. The seatbelt warning.
2. Key in/lights on warning.
3. Lights 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 FUNCTIONS

Scheme 39

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

1. SLABS ECU.
2. BCU.
3. ECM (V8 and Td5).
4. IDM.
5. ACE ECU.
6. EAT ECU.
7. SRS 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

1. Automatic or manual gearbox fitted.
2. Diesel or V8 engine fitted.
3. ACE fitted.
4. SLS fitted.
5. Gulf, Japan or ROW markets.

1. Service engine reset.
2. Odometer reset.
3. HDC fitted.
4. Traction control fitted.

The serial communications link is a bi-directional communications network providing both input and output on the same pin.

A feed from the battery positive terminal is connected on an R wire to the engine compartment fusebox where it passes through fusible link 8 and fuses 10 and 13.

A permanent feed from fuse 13 is connected to the passenger compartment fusebox on a PN wire. The feed is connected from the passenger compartment fusebox to the instrument pack on a PO wire.

A feed from fusible link 8 is connected on an NW wire to the passenger compartment fusebox and from the fusebox to the ignition switch on an N wire.

Ignition Switch Circuit Supply

With the ignition switch in position II, the feed from fusible link 8 flows through the ignition switch to the passenger compartment fusebox on a Y wire, where it passes through fuses 25, 27, and 35. Fuse 27 is connected on an LG wire to the instrument pack.

Fuse 35 is connected to the instrument pack on a G wire. Fuse 25 is connected to connector interface C1837/C1838 on a GY wire. The connector interface supplies a feed to the differential lock resistor on a KG wire.

Internal Voltage Supplies

Some of the warning lamps operate at very low voltages, the reduced voltages are controlled by the instrument pack. The instrument pack is earthed from pin C0230-17 and pin C0230-18 to earth header C0551 on B wires.

Scheme 40

Certain vehicles have an interior rear view mirror that features an automatic photochromatic dimming function and an electronic compass with LED display.

The compass mirror is a self-contained unit and does not interface with any other vehicle system or electronic control unit. The mirror is fixed to a metal bracket attached to the windscreen.

A three pin connector provides the electrical connection to the mirror's internal circuit board. Pin-1 of the connector provides the 12V power supply to the board via the auxiliary relay located in the engine compartment fusebox. When the ignition switch is turned to the 'II' position, a 12V supply is provided to energize the coil of the auxiliary relay via fuse 26 in the passenger compartment fusebox. The auxiliary relay's contact supply voltage is provided from the vehicle battery through fusible links 1 & 7. When the relay's contacts close, a 12V supply is fed to the compass mirror circuit board via fuse 15 in the passenger compartment fusebox. This is the supply voltage feed for the mirror's internal compass.

Pin-2 of the electrical connector provides the path to earth.

Pin-3 of the electrical connector is a 12V ignition switched supply voltage (position 'II' of the ignition switch). The supply voltage is provided to the mirror's circuit board via fuse 25 in the passenger compartment fusebox, and the reverse lamp switch (normally closed) for vehicles with manual transmission or the starter inhibitor / reverse light switch (normally closed) for vehicles with automatic transmission. This is the supply voltage feed for the mirror's photochromatic dimming function.

Compass

The mirror's compass display is activated when the ignition switch is turned to position 'II'. If the compass has been previously calibrated, the current direction of the vehicle will be shown in the LED display at the upper RH side of the mirror's reflective surface. The display is able to indicate one of eight compass points (i.e. N, NE, E, SE, S, SW, W or NW).

The compass mirror circuit board contains a microchip which is able to determine changes in vehicle direction due to the changes in the earth's magnetic field. The circuit board is located in the stem of the mirror so that it follows the changes in the vehicles direction and is not affected by adjustment of the mirror itself.

Because of changes in the lines of magnetic influence, the compass is set for operation in one of fifteen different zones depending on the current location of the vehicle. If the vehicle is to be driven in a different zone, the compass will have to be reset for operation in that zone. To determine the correct zone for a particular location on the planet, refer to the maps provided in the Owner's Handbook. The mirror's default setting is zone 8 which is suitable for central European countries (Germany, Austria, Italy etc.).

The compass should be set to the correct zone using the following procedure

1. Switch the ignition to position 'II'. If the compass displays one of the eight compass point directions, proceed to step '3'. If the compass displays 'C' then proceed to step '2'. If the display does not show either of the above, then the calibration button on the underside of the mirror should be pressed and held for approximately 6 seconds, using a small probe (e.g. paper clip or ballpoint pen). The compass should now enter the set mode and 'C' should be shown in the display.
2. To calibrate the compass, the vehicle must be driven slowly (5 mph (8 km/h) or less) in a circle until the display shows a direction (usually 1 or 2 revolutions). The mirror can calibrate itself during normal driving, but this will take considerably longer.
3. Set the compass to the relevant zone of magnetic influence by pressing the calibration button on the underside of the mirror for approximately 3 seconds, using a small probe, until a number is shown in the display. If the zone is being entered for the first time, the default zone setting '8' should be displayed. If the zone is being reset from a previous entry, the previous zone setting number will be displayed. The calibration button should now be pressed and released with single presses, using a small probe, until the desired zone number appears in the display. After approximately 10 seconds, the compass display should return correctly set to the required zone.

Note the degree of magnetic variation from one zone to another is only very slight. Recalibration of the compass is not normally necessary unless several zone changes are undertaken.

Automatic dimming

The mirror's automatic dimming function operates when the ignition switch is turned to the 'II' position. A light sensor is contained at the upper center of the mirror which detects the intensity of light from the headlights of following vehicles in dark or low light conditions. When the light intensity is sufficiently high, the mirror automatically adjusts the brightness of the reflected light by photochromatically changing the mirror's reflective properties and so preventing glare affecting the driver.

When reverse gear is selected, the power supply for the mirror's photochromatic function is opened so that the mirror defaults to its normal reflective properties while the reversing operation is in progress.

Another light sensor is located on the rear of the mirror so that the unit can detect the difference between strong ambient light and that attributable to following vehicle headlights. To check operation of the light dimming function of the mirror, use the following procedure

1. Turn ignition switch to position 'II', and ensure reverse gear is not selected.
2. Cover the sensor on the back of the mirror.
3. Shine a bright light on the front (reflective side) of the mirror; the mirror should darken.

Scheme 41

1. Carefully remove clock assembly from fascia.
2. Disconnect multiplugs from clock and door locking switches.
3. Remove door locking switch from clock assembly and remove clock assembly.

Refit

1. Fit door lock switch to clock assembly and connect multiplugs.
2. Position and push to secure clock assembly to fascia.

Scheme 42

1. Disconnect battery earth lead.
2. Remove fuel pump assembly. Refer to «REMOVAL & INSTALLATION (DISCOVERY SERIES II)»(ref-24297-S03750102802001010400000) .
3. Disconnect 2 Lucars from top of pump unit assembly.
4. Release 2 spring clips securing sender unit to fuel pump assembly.
5. Remove sender unit.

1. Position sender unit into location slots and engage spring clips.
2. Connect Lucars to top of pump unit assembly.
3. Fit fuel pump assembly. Refer to «REMOVAL & INSTALLATION (DISCOVERY SERIES II)»(ref-24297-S03750102802001010400000) .
4. Connect battery earth lead.

Scheme 43

1. Remove steering column nacelle. Refer to «REMOVAL»(/land-rover/discovery/l318-2002-2004/remont/manual-power-steering/#steering-system) .
2. Remove 2 screws and release instrument cowl from 2 clips on fascia.
3. Disconnect 7 multiplugs from switches.
4. Remove instrument cowl.
5. Remove 4 screws securing instrument pack to fascia.
6. Disconnect 2 multiplugs from instrument pack.
7. Remove instrument pack.

1. Position new instrument pack and connect multiplugs.
2. Align instrument pack to fascia and secure with screws.
3. Position instrument cowl and connect multiplugs to switches.
4. Fit instrument cowl to clips and secure cowl with screws.
5. Fit steering column nacelle. Refer to «INSTALLATION»(/land-rover/discovery/l318-2002-2004/remont/manual-power-steering/#steering-system) .

See also:
• ROLLING ROAD (DYNO) TESTING
• REMOVAL