Land Rover Discovery Owners & Service Manuals

Land Rover Discovery: Instrument Cluster

NOTE:

The following illustration shows the display when the transmission is in CommandShift mode. PRNDS is displayed during normal transmission operation.

Instrument cluster

  1. Malfunction Indicator Lamp (MIL)
  2. Gear indicator (Dynamic mode)
  3. Transmission indicator

The instrument cluster is connected to the TCM via the high speed CAN powertrain systems bus. Transmission status is transmitted by the TCM and displayed to the driver in the instrument cluster.

For additional information, refer to: Instrument Cluster (413-01 Instrument Cluster, Description and Operation).

Malfunction Indicator Lamp (MIL)

The MIL (malfunction indicator lamp) is located in the upper right side of the instrument cluster, within the tachometer. Transmission related faults which may affect the vehicle emissions output will illuminate the MIL.

The MIL is illuminated by the ECM on receipt of a relevant fault message from the TCM on the high speed CAN powertrain systems bus. The nature of the fault can be diagnosed using a Land Rover approved diagnostic system which reads fault codes stored in the memory.

Transmission Status Display

The transmission status display is located in the central Thin Film Transistor (TFT) message display in the instrument cluster. The display shows the selected P R N D S position and the current selected gear in normal transmission modes. In Drive 'D' the current gear is not displayed unless the paddle switches are operated.

In Dynamic (Sport) mode, the selected transmission gear is displayed in a central position in the TFT display.

DRIVING MODES

A number of different driving modes are available. Some can be selected by the driver and some are automatically initiated by the TCM to adapt to different driving conditions.

  • Normal
  • Sports
  • Manual 'CommandShift'
  • Cooling
  • Hill Descent Control (HDC)
  • Cruise
  • Limp home
  • Coast
  • Fast off recognition
  • Uphill and Trailer
  • Downhill
  • Wide Throttle
  • Terrain Response
  • Reverse lock-out
  • Kick-Down
  • Shift Adapt Under Braking
  • Corner Recognition
  • Road Gradient Recognition
  • Driver Type Recognition

Normal

Normal mode is automatically selected by the TCM when the ignition is switched on (ignition mode 6). In this mode all automatic and adaptive modes are active. Normal mode uses gear shift and lock-up maps which provide the optimum of fuel consumption, emissions and driveability, depending on the driving style.

If the transmission is operated in sport mode or 'CommandShift' mode and the TCS is moved back to the drive 'D' position, then normal mode operation is resumed.

Sports

Sports mode provides enhanced acceleration and responsiveness by the use of sports shift maps. This mode allows the transmission to down shift more readily and hold gears for longer at higher engine speeds.

Manual 'CommandShift'

Manual 'CommandShift' mode allows the transmission to operate as a semiautomatic transmission. The driver can change up and down the nine forward gears with the freedom of a manual transmission provided the requested gear is within the allowed engine and vehicle speed range.

Shift maps are provided to protect the engine at high speeds. The TCM will automatically change up to a higher gear ratio to prevent engine overspeed and change down to a lower gear ratio to avoid engine laboring and stalling.

When kick-down is requested the TCM shifts down to the lowest available gear. When the vehicle is stationary, the driver can select 1st or 2nd to start off.

Upshifts (+) are optimized for performance via the short shift function, resulting in firmer feeling shifts than in automatic mode. Downshift requests (-) utilize a throttle 'blip' during the shift, resulting in an improved shift feel.

Temporary Manual Gear Selection

With the TCS in the 'D' position, manual mode can be directly accessed by the single action of operating one of the steering wheel paddle switches.

This allows immediate, but temporary use of the shift paddles when the TCS is in 'D'. If continued use of manual mode is required, the TCS must be moved to the Sport 'S' position to enter permanent manual mode in the currently selected gear.

If the TCS remains in the 'D' position, temporary manual mode will be held while the driver is accelerating, decelerating, cornering or continuing to request shifts using the paddle switches. The transmission will revert back to automatic operation after a short period of driving at a steady speed.

Alternatively, the upshift (+) paddle can be held for approximately 2 seconds to return to automatic mode in TCS position 'D'.

Permanent Manual Gear Selection

Select the 'S' position on the TCS, permanent manual mode is then accessed by the operation of the steering paddle switches. The instrument cluster message center will show the currently selected gear. To exit from manual mode, pull and hold the upshift (+) paddle switch for approximately 2 seconds to return to automatic operation in Sport (S) mode. Alternatively, rotate the TCS to the 'D' position; the transmission will revert to 'D' automatic mode.

Manual Operation

Upshifts are performed using a brief operation of the upshift (+) paddle switch. Downshifts are performed using the downshift (-) paddle switch. The message center will display the selected gear.

The transmission will inhibit upshifts and downshifts if the requested shift would result in an engine speed outside the engine's operating range.

Commandshift - Additional Features

Kick-Down: - Operation of kick-down mode will override the currently selected gear. The lowest available gear will be selected for maximum acceleration and will be highlighted in the message center. Subsequent manual shifts may then be selected as usual.

Positive Torque: - Provides throttle 'blips' on downshifts, improving transmission shift quality and response.

Shift Assist: - The transmission will automatically upshift at the engine speed redline in CommandShift mode, as if operated manually. The transmission will automatically downshift, when the engine speed falls below the range for the currently selected gear. When the vehicle approaches, or comes to rest, second gear is automatically selected.

Subsequent starts from standstill will occur in second gear, unless accelerator pedal demand is high or a downshift is manually selected, in which case first gear will be selected. In all cases the message center will show the currently selected gear.

During sustained braking, if a downshift is selected at a speed which would result in an engine speed outside the engine's operating range, the downshift will be delayed until the vehicle speed has reduced sufficiently for the gear selection to be made, without causing the engine speed to exceed its normal operating range.

Cooling

Cooling mode is activated when the TCM detects excessively high ATF or engine coolant temperatures. When this mode is active, torque converter lock-up is activated earlier to minimize a further rise in ATF and/or engine coolant temperature and assist ATF cooling.

Hill Descent Control (HDC)

The HDC mode assists the ABS control module in controlling the downhill speed of the vehicle. When HDC is active, the TCM selects the most appropriate gear for the descent to maximize engine braking.

Maximum engine braking is applied using a shift map which initiates later upshifts and early downshifts.

Cruise

When speed control is activated, the TCM receives a speed control active message on the high speed CAN powertrain systems bus. The TCM activates a speed control map which minimizes up and down shifts.

Cruise mode is active when speed control is selected to 'on' and the transmission is in drive 'D', Sport 'S', HDC or a Terrain Response Grass/gravel/snow program. Unique cruise maps override the current mode to provide a smooth driving feel and mode reselection.

Limp Home

If a transmission fault is detected by the TCM, the TCM adopts a limp home strategy and a message 'TRANSMISSION FAULT LIMITED GEARS AVAILABLE' is displayed in the message center. If the fault has an effect on engine emissions, the MIL in the instrument cluster will also be illuminated.

In limp home mode, P, R and N functions operate normally (if the fault allows these selections) and the TCM locks the transmission in an available gear to allow the driver to take the vehicle to a Land Rover dealer or approved repairer. Torque converter lock-up is disabled and reverse-lockout will not function.

If the vehicle is stopped and subsequently restarted in the limp home mode condition, the TCM operates normally until the fault which caused the condition is detected again.

Coast

Coast mode provides earlier downshifts during coasting dependant on output shaft deceleration rate to improve driveability and refinement by avoiding negative to positive driveline torque reversal transmissions during the downshifts.

Fast Off Recognition

Fast off recognition is activated when the TCM detects that the driver has released the accelerator pedal quickly. This is detected by the TCM monitoring for a high level of negative pedal angle from ECM signals on the high speed CAN Powertrain systems bus. If this condition is detected, the TCM holds the current gear ratio to allow the driver to complete the manoeuvre without the need for a downshift. The mode can remain active for a predetermined length of time or if the driving style remains passive.

Fast off recognition mode assists vehicle stability and is used in conjunction with a lateral acceleration input during cornering to maintain the current gear until the corner is negotiated.

Uphill and Trailer

Uphill and trailer mode can be active when the transmission is operating in normal, sport or Terrain Response modes. When the vehicle is pulling a trailer or driving up an incline, the TCM detects the increased resistance by monitoring engine torque and speed signals received from the ECM on the high speed CAN powertrain systems bus and also transmission output shaft speed sensor signals. Uphill and trailer mode will provide downshifts to prevent a drop in transmission torque output and maintain driving force.

Downhill

Downhill mode can be active when the transmission is operating in normal, sport or Terrain Response modes. When the vehicle is descending an incline, the TCM detects a reduction in resistance by monitoring engine torque and speed signals received from the ECM on the high speed CAN powertrain systems bus and also transmission output shaft speed sensor signals. Downhill mode assists engine braking by selecting an appropriate gear reducing the load required on the brakes.

Wide Throttle

Wide open throttle mode operates for part throttle upshifts and kick-down upshifts. It provides consistent wide open throttle upshift performance under all driving conditions. The full engine speed range is used in all driving modes; normal, sport, hill modes and CommandShift.

Compensation is used for delays (hydraulic and electronic) in gear change request to gear change start to provide smooth changes and correct shift point correction.

Terrain Response

The Terrain Response system has a unique set of shift maps for each of the Terrain Response programs. These programs override existing modes; for example when HDC is active and the 'Sand', 'Mud and Ruts' or 'Grass/Gravel/Snow' programs are selected, a specific Terrain Response map is used, not the HDC mode shift map detailed previously.

Reverse Lock-Out

If the TCS is moved from N to R and the vehicle is travelling forwards, reverse selection is prevented if the vehicle speed is 5 km/h (3 mph) or more.

The same strategy is applied if the vehicle is moving backwards and D or S are selected on the TCS, the selection will be prevented if the vehicle speed is 5 km/h (3 mph) or more.

Kick-Down

When D is selected and the accelerator pedal is fully depressed, the transmission will down-shift to the lowest appropriate gear. Once the accelerator pedal is returned to a normal driving position, the transmission will upshift to the highest appropriate gear. Kick-down will vary according to road speed, current gear selection and accelerator pedal movement.

Shift Adapt Under Braking

Under braking, the transmission will vary the downshift point in proportion to braking effort and road gradient. This feature works in conjunction with the positive torque function, resulting in a smoother down-shift. If Sport mode S is selected, driver type recognition will vary the activation of this feature according to driving style.

Corner Recognition

Corner recognition inhibits up-shifts during cornering to provide improved vehicle balance. If Sport mode S is selected, driver type recognition will vary the activation of this feature according to driving style.

Road Gradient recognition

When the vehicle is driven on an uphill gradient, the transmission adapts the shift pattern to make better use of the engine power.

When the vehicle is driven on a long downhill gradient, the transmission may automatically select a lower gear to increase engine braking. Selecting Sport mode S will increase the tendency of the transmission to select a lower gear in these conditions, further increasing engine braking.

It is also possible to select a lower gear to increase engine braking using the gear shift - paddle switch.

Driver Type Recognition

In Sport mode S, the transmission monitors driving style and in combination with other vehicle systems, varies the shift schedule, fast off, corner recognition and shift adapt under braking functions according to the driving style.

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