Realtime live display of the information the electronic control unit of the selected vehicle system is currently deriving from its input sensors.
VOLTAGES
- Pump monitor: This shows the voltage being measured at the ABS pump relay by the SLABS ECU. When driven, the voltage at the pump should be around 2.9 to 3.8 Volts and when not being driven, it should be around 0 to 0.2 Volts.
- Pump relay: This shows the voltage being applied to the ABS pump relay by the SLABS ECU. When driven, the voltage should be around 2.8 to 3.6 Volts and when not being driven, should be around 0 to 0.5 Volts.
- Ground reference: This shows the DC value for the reference ground. Expected values are between -0.5 to +1 Volt.
- Hill descent control brake: This shows the voltage being applied to the Hill Descent Control (HDC) Brake control Relay by the SLABS ECU. When driven the voltage should be around 2.8 to 3.6 Volts and when not being driven should be around 0 to 0.5 Volts.
- Inlet valve: This shows the voltage being applied to this valve by the SLABS ECU. When driven, the voltage should be around 2.8 to 3.6 Volts and when not being driven, should be around 0 to 0.5 Volts.
- Outlet valve: This shows the voltage being applied to this valve by the SLABS ECU. When driven, the voltage should be around 2.8 to 3.6 Volts and when not being driven, should be around 0 to 0.5 Volts.
- Sensor: This shows the DC Voltage for the wheel speed sensor. Expected values are between 2.0 to 2.4 Volts. The wheel speed sensors are different to the conventional wheel speed sensors used on other Land Rover products. Conventionally, wheel speed sensors have an interference fit with the hub or back plate. This positions the sensor close to a reluctor ring. The sensors used on New Discovery series II are incorporated into the inboard wheel bearing, on both front and rear hubs. This bearing assembly is a sealed unit and has no replaceable parts. Also different is the wire from the wheel speed sensor. Land Rover has, historically used a wheel speed sensor employing a signal wire inside a shielded earth wire. The New Discovery series II wheel speed sensors have a twisted pair of wires. This offers some electrical advantages over two straight wires. Such as the signal being less susceptible to electrical noise or interference and it generates less electrical noise, the wires can also be balanced together (similar electrical properties) to ensure voltage losses are minimized. Like a conventional wheel speed sensor, the signal created is an AC sine wave. This wave is generated in the inductive sensor by a sixty-tooth reluctor, machined into the wheel bearing inner race. The frequency of this signal supplies the SLABS ECU with the information it needs to determine the speed of the individual wheels and is used in the calculation of vehicle speed or vehicle reference speed.
- Rear left/right sensor supply: This shows the voltage of the left/right rear height sensor supply. Expected values are 4.7 to 5.6 Volts.
- Left/Right valve voltage: This is the voltage measured at the left/right rear air suspension valve.
- Compressor relay: This is the voltage measured at the air suspension compressor / control.
- Exhaust valve: This is the voltage measured at the air suspension's exhaust valve.
- Internal ECU supply: This shows the SLABS ECUs internal supply voltage.
- Battery voltage: This is the current battery voltage being supplied to the SLABS ECU.
SWITCHES SPEED AND VALUES - The inputs will change if the vehicle is moving. Open the inputs page, and then start the engine. Drive the vehicle at a low speed. Once the speed of 8km/h was reached for all four wheels, the communication will stop.
- Height left sensor value: This shows the current height value of the rear left air suspension height sensor. A value of 1 is equal to approximately 1.4 mm between the wheel arch and ground.
- Height right sensor value: This shows the current height value of the rear right air suspension height sensor. A value of 1 is equal to approximately 1.4 mm between the wheel arch and ground.
- Front left wheel speed: The wheel speed in Km/h. The SLABS ECU cannot detect wheel speeds less than 1.8 KPH. The wheel speed sensors are different to the conventional wheel speed sensors used on other Land Rover products. Conventionally, wheel speed sensors have an interference fit with the hub or back plate. This positions the sensor close to a reluctor ring. The sensors used on New Discovery series II are incorporated into the inboard wheel bearing, on both front and rear hubs. This bearing assembly is a sealed unit and has no replaceable parts. Also different is the wire from the wheel speed sensor. Land Rover has, historically used a wheel speed sensor employing a signal wire inside a shielded earth wire. The New Discovery series II wheel speed sensors have a twisted pair of wires. This offers some electrical advantages over two straight wires. Such as the signal being less susceptible to electrical noise or interference and it generates less electrical noise, the wires can also be balanced together (similar electrical properties) to ensure voltage losses are minimized. Like a conventional wheel speed sensor, the signal created is an AC sine wave. This wave is generated in the inductive sensor by a sixty-tooth reluctor, machined into the wheel bearing inner race. The frequency of this signal supplies the SLABS ECU with the information it needs to determine the speed of the individual wheels and is used in the calculation of vehicle speed or vehicle reference speed.
- Off road switch: This shows the current status of the SLABS ECUs off road switch input.
- Hill descent control switch: The state of the Hill Descent Control switch input on the SLABS ECU.
- Neutral switch: The state of the neutral / transmission switch input of the SLABS ECU. This input should never indicate GND on a manual gearbox equipped vehicle.
- Differential lock switch: This shows the state of the Differential Lock input on the SLABS ECU. Manual engagement of the Differential Lock can only be done from under the vehicle. ABS is disabled, and the ABS warning light remains on, while the Differential Lock is engaged.
- Reverse: The state of the Reverse Gear switch input of the SLABS ECU.
- Shuttle: The modulator houses two shuttle valves, which are moved when brake pressure is supplied via the brake master cylinder's dual channels. The shuttle valves have a switch attached to them, along with a set of resistors located between them. The resistance of the circuit controlled by these shuttle valve switches will change depending upon the position of the shuttle valve. With no brake pressure supplied, the current flows through the three resistors. With one switch open, the current flows through two of the resistors, and when both are open it will flow through only one. The switches can switch at slightly different times because of the internal workings of the master cylinder. The signal from the shuttle valve is used by the SLABS ECU to detect the correct operation of the brake master cylinder and the integrity of the braking circuit, and is used to supply a brake on(tm) signal. The vehicle still has a brake light switch. This switch is used to control the brake lamp operation and the cruise control inhibitor. This shows the state of the shuttle switches input on the SLABS ECU. Valid states are:
- OPEN CIRCUIT: Which means that either the wiring harness or the switches are faulty.
- BOTH OPEN: Means that the brake pedal is released and the hydraulics are under HDC/ETC control.
- ONE CLOSED: Can possibly be shown during transition states or under light braking conditions.
- BOTH CLOSED: Indicates that the Brake pedal is depressed and the hydraulics are under ABS control.
- SHORT TO GROUND: Indicates that either the harness or the switches are faulty.
- Low range: Shows the state of the Low Range switch input line to the SLABS ECU. To change from low to high range you must ensure that the brake pedal is depressed, and neutral gear is selected.
- Any door ajar: This shows the current status of the door switch input of the SLABS ECU. The ECU inhibits motion of the vehicle if any door is detected as being open.
- RPM: This shows the engine current number of Revolutions Per Minute. The SLABS ECU cannot detect engine RPMs of less than 300. This means that any value below 300 RPM should be read as 0.
- Throttle angle deg: This is the deflection of the throttle pedal measured in degrees.
- Plip signal: This shows the current status of the plip input line to the SLABS ECU from the BCU. The states are:
- GROUND: the signal line has been detected as being shorted to ground which is a fault.
- LOWER: this means that the BCU is currently sending a request to lower the vehicle.
- NEUTRAL: this means that the signal line is normal with no height change requests being made.
- RAISE: this means that the BCU is currently sending a request to raise the vehicle.
- OPEN CIRCUIT: The signal line is detected as being open circuit and is therefore faulty. If the signal line is shorted to battery supply voltage this will also be shown as open circuit.
- Engine torque (Nm): This shows the current engine torque in Newton meters.
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