The diagnostic connector allows information to be exchanged between the various bus-connected control units and Land Rover approved diagnostic equipment. This allows you to quickly search for diagnostic information and program specific functions using Land Rover approved diagnostic equipment.
Fault detection
The air suspension control unit performs fault diagnosis and plausibility checks. Only those faults are detected that the control unit can detect by direct measurements:
- Sensor wiring faults
- Valve wiring faults
- Malfunctions of supply circuits of sensors and actuators
- Bus failures
- Control Unit Hardware Faults
Plausibility checks and signal behavior checks:
- Incorrect change in the average height value Too slow change in height
- Too slow height change
- Gallery pressure Does not increase fast enough when reservoir fill is requested Increases when system is inactive Too low when height is requested Increases too quickly when receiver is full Does not decrease when gallery is purged Pressure changes too much when system is inactive.
- Does not rise fast enough when requesting to fill the receiver
- Raises when the system is idle
- Too low when requesting an increase in height
- Rising too fast when the receiver is full
- Does not decrease when blowing the gallery
- Pressure changes too much when the system is inactive
- Compressor temperature Sensor voltage too low - head and brush sensors (short circuit to battery) Takes too long to read data after sufficient compressor operation - head and brush sensors Does not increase when compressor is on - only head sensor
- Sensor voltage too low - head and brush sensors (short circuit to battery)
- It takes too long to read data after sufficient compressor operation - head and brush sensors
- Does not increase when compressor is on - head sensor only
- Sensor operation "Swimming" signal Constant rotation when driving
- "Swimming" signal
- Constant rotation while moving
When a malfunction is detected, the air suspension control unit tries to maintain driving comfort and as much functionality as possible.
The functionality of the system is determined by the severity of the failure.
Faults
Faults are categorized according to their severity and affect the operation of the system in the following ways: (where 1 is a minor fault and 5 is a major fault):
- Faults (hardware) height sensors and receiver valve block failure Maintains full functionality without "thin" possibilities, for example, if the bypass valves are turned off, the unevenness of the road surface is not compensated.
- Full functionality is retained "thin" possibilities, for example, if the bypass valves are turned off, the unevenness of the road surface is not compensated.
- Pressure sensor faults, compressor faults, damper valves stuck closed No vehicle speed signal At the next request, the vehicle returns to road mode. Alignment on "current" height.
- No vehicle speed signal
- At the next request, the vehicle returns to road mode.
- Alignment on "current" height.
- Receiver valve sticking open, exhaust valve sticking closed at a height below the road driving height, shock absorber valves sticking open at a height above the road driving height. At the next request, the vehicle returns to road mode. Alignment on "current" height is not met.
- At the next request, the vehicle returns to road mode.
- Alignment on "current" height is not met.
- Malfunction of several height sensors, lateral rotation when moving, calibration failure. The vehicle is lowered onto the compression stroke buffers.
- The vehicle is lowered onto the compression stroke buffers.
- ABS module failure, CAN bus failure If the air suspension control unit loses communication with the ABS module, or the ABS module reports a fault, the air suspension control unit returns altitude immediately "default" below the height corresponding to the mode of movement on the road. When the default height is reached, the control unit continues to level the vehicle at that height. It is unlikely that the air suspension control unit is defective. After the malfunction is eliminated, the air suspension control unit will resume full operation, however, the error will be stored in the memory of the control unit.
- If the air suspension control unit loses communication with the ABS module, or the ABS module reports a fault, the air suspension control unit immediately returns the altitude "default" below the height corresponding to the mode of movement on the road. When the default height is reached, the control unit continues to level the vehicle at that height. It is unlikely that the air suspension control unit is defective. After the malfunction is eliminated, the air suspension control unit will resume full operation, however, the error will be stored in the memory of the control unit.
In case of significant malfunctions, the control unit does not align the vehicle on "current" height. The control unit stops changing the height until a manual or automatic request for changing the height is received. The control unit returns to the standard height, if possible, and stops control when this height is reached.
If the suspension is in a position higher than the road mode height, the air suspension control unit will not be able to lower the suspension and all height changes will be stopped. The control unit will send a message over the high speed CAN bus to the instrument panel, which will display the maximum recommended speed on the message center display. Immediate termination of the change in vehicle height is carried out in the following cases:
- Malfunction of several height sensors - vehicle on compression stroke buffers
- Signs of an unreliable turn are registered - the car is on the buffers of the compression stroke
- Valve or solenoid failure - damper valve sticking open when ride height is below road ride height, or exhaust valve sticking closed when ride height is above road ride height.
- Stuck damper valve or all valves (during diagnostics, the reliability of sensor signals is evaluated).
If it is not possible to change the height, for example, due to a stuck exhaust valve at a suspension height corresponding to the road mode, or a compressor failure at a suspension height corresponding to the driving mode, the control unit will not level and change the height.
In the event of a hardware failure of the air suspension control unit, the control unit disables all air suspension functions. The following hardware errors are logged: memory errors, control unit malfunctions, and calibration errors.
Fault messages
The air suspension system informs the driver of malfunctions via the air suspension switch LED and instrument cluster message center.
In case of minor faults, when the air suspension control unit can align the vehicle on "current" height, the air suspension switch LED indicates the current height.
In the event of a serious malfunction of the air suspension control unit, when the air suspension control does not work, all control switch LEDs turn off.
If, in the event of a malfunction, the air suspension control unit can determine the height of the suspension, and it does not exceed the height corresponding to the mode "ON-ROAD", the following warning appears in the information center display: "air suspension fault max speed 30 mph (50 km/h) " (air suspension failure, max. speed 50 km/h).
If the control unit cannot determine the suspension height, or the height exceeds the road mode height, cannot be lowered, and the vehicle speed is too high, an air suspension fault message is displayed.
If the only available height is road mode, a message is displayed indicating that the air suspension is faulty and that only normal height is available.
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