Operating principles (Freelander 2)

The windscreen wiper and washer system can operate in different modes when the vehicle is in power mode 4 to 8. Requests from the right steering column multifunction switch are transmitted via the LIN bus to the CJB, which is the main control unit for the system.

Low speed windshield wiper

When a request for low speed windscreen wiper operation is received, the CJB energises relay 11 in the BJB. When energised, relay 11 energises the changeover contacts of relay 8, which is also located in the CJB. Relay 8 is a fast/slow wipe relay. When a request for low speed wipe is received, relay 8 remains de-energised, allowing current to flow through the changeover contacts of the relay and to the low speed brush contacts of the windscreen wiper motor.

High speed windshield cleaning

When a request for high speed windscreen wiper operation is received, the CJB energizes relay 11 and relay 8 in the BJB. When energized, relay 11 energizes the changeover contacts of relay 8. When energized, relay 8 energizes the high speed brush contacts of the windscreen wiper motor.

Intermittent windshield cleaning

When a request is received for intermittent windscreen wiper operation, the CJB energises relay 11 in the BJB to operate the windscreen wipers at low speed. The CJB software interprets the requested time delay and controls relay 11 accordingly.

The intermittent cleaning settings are transmitted via the LIN bus to the CJB, which equates them to the following time delays.

LIN bus signal	Time delay (seconds)
1	22
2	15,5
3	9,5
4	6
5	3,5
6	1

If the LIN bus between the CJB and the right steering column multifunction switch fails, the CJB will enter fail-safe mode (see below).

Automatic windshield cleaning

When a request for automatic windscreen wiper operation is received, the CJB interprets the messages received via the LIN bus from the rain sensor. The messages from the rain sensor transmitted via the LIN bus have values from 0 to 7. The CJB interprets the signal value 0 as no water on the windscreen.

A signal value of 1 to 5 is interpreted by the CJB as a small amount of water on the windscreen. In this case, the CJB initiates the low-speed wiper mode described in the "Low-speed windscreen wiper" section above.

A signal value of 6 to 7 is interpreted by the CJB as a large amount of water on the windscreen. In this case, the CJB initiates the high-speed wiper mode described in the "High-speed windscreen wiper" section above.

The sensitivity of the rain sensor can be adjusted by setting the rotary control on the right-hand steering column multifunction switch to the desired position. Six different sensitivity settings are available, which are transmitted via the LIN bus to the CJB.

NOTE: If the rain sensor value is below 4, the CJB will only switch from high-speed wiper mode to low-speed wiper mode.

(Original version of the article on the website www.LRman.ru)

Single Windshield Cleaning

When a single wipe request is received, the CJB will operate the windscreen wipers as described in the Low Speed Wipe section above until the request is cleared.

Parking position of windshield wipers

The windshield wiper park switch is integrated into the windshield wiper motor. The park switch ensures that the windshield wipers return to the park position if the windshield wiper request is cancelled mid-stroke.

The CJB is connected to one side of the parking switch. The parking switch contacts are open when the wipers are in any position except the park position. While the switch contacts are open, the CJB continues to supply power to relays 11 and 8 in the BJB, even if a request to stop the wipers is received via the LIN bus from the right steering column multifunction switch.

When the wipers reach the park position, the parking switch contacts close and a ground connection is created. When the CJB registers this ground connection, the CJB software determines that the wipers are in the park position and de-energizes relays 11 and 8 in the BJB.

Windscreen wiper emergency mode

If the LIN bus between the CJB and the right steering column multifunction switch fails while the windscreen wipers are active, the CJB will enter the fail-safe mode. In fail-safe mode, the CJB will only supply power to the windscreen wipers for low-speed wiping.

Windshield wiper service position

The wipers can be stopped on the windshield to facilitate the installation of new blades. For more information, refer to the "Owner's Manual".

Rear window cleaner

When a request for rear wiper operation is received, the CJB energises relay RA2 in the AJB. When energised, relay RA2 energises the rear wiper motor. The rear wiper operates intermittently with a delay of approximately 6 seconds between wipe cycles. The CJB controls relay RA2 and therefore the rear wiper motor.

The CJB also supplies power to the parking position switch of the rear window cleaner's electric motor. The parking position switch is integrated into the rear window cleaner's electric motor and ensures that the wiper returns to the parking position if the request for operation of the rear window cleaner is canceled in the middle of the stroke. The parking position switch contacts are closed when the rear window cleaner is in any position other than the parking position. This allows the CJB to return the rear window cleaner to the parking position when the RA2 relay is de-energized.

The CJB also supplies power to the rear wiper motor if reverse gear is selected while the windscreen wipers are operating. On vehicles equipped with an automatic transmission, the reverse gear signal is generated by the transmission control module (TCM). The TCM transmits the reverse gear signal via the high speed CAN bus to the CJB, which in response operates the rear wiper.

On vehicles equipped with a manual transmission, the reverse gear signal is generated by the reverse gear switch. The reverse gear switch is rigidly connected to the CJB.

Windshield washers

When a request is received for the windscreen washer to operate, the CJB energises the windscreen washer control relay. This supplies battery power to the washer pump. The pump ground is provided by the de-energised rear washer control relay. Both washer control relays are integrated into the CJB.

When a request to turn on the windscreen washer is received, the windscreen washers will be turned on. After pressing the washer switch, the CJB will delay the activation of the windscreen wipers for 100 ms. If the switch is pressed for less than 100 ms, the CJB will not turn on the windscreen wipers.

The CJB will supply power to the windscreen wipers as long as there is a request for washers, although the washers will go into an idle state after 10 seconds. Once the washer switch is released, the CJB will operate the windscreen wipers for an additional 2 wipe cycles.

Rear window washer

When a request is received for the rear washer to operate, the CJB energises the rear washer control relay. This supplies battery power to the washer pump. The pump ground is provided by the windscreen washer control relay being de-energised. Reversing the polarity of the pump (see Windscreen Washers above) allows washing fluid to be directed to both the rear washer nozzle and the windscreen washer nozzles. The rear washer nozzle is integrated into the high mounted brake lamp.

When continuously requested, the rear window washer will operate for up to 10 seconds. When a request is made to operate the rear window washer, the rear window wiper will operate continuously until the switch is released. Once the switch is released, or after 10 seconds of continuous operation, the CJB will operate the rear window wiper for an additional 2-3 wipe cycles.

Headlight washer

When the vehicle is in ignition mode 4 (accessory power) to 7 (engine running), the first windscreen wash request longer than 100 ms will also activate the headlamp washers. The CJB will then start a 10-minute timer. If there are 5 windscreen washers requests during this 10-minute period, the CJB will activate the headlamp washers on the fifth request. In this case, the 10-minute timer is reset to 0.

If the CJB does not receive any windscreen washer requests during this 10 minute period, the headlamp washers will be activated at the first request received after 10 minutes have elapsed. Once the headlamp washers are activated, the CJB resets the timer to 0.

The headlamp washers only operate when the headlamps are on. The CJB receives a "lights on" signal via the LIN bus from the lighting control module.

When the headlamp washers are required, the CJB supplies power to relay 9 in the BJB, which supplies battery voltage to the headlamp washer pump. The pump is connected to ground by de-energising relay 12, also in the BJB. This sequence supplies fluid to the headlamp nozzles 1.

After this sequence is completed, the power supply to the pump is reversed. The CJB de-energizes relay 9 and energizes relay 12. This supplies fluid to the headlight injectors 2. The sequence is as follows:

• Power to headlamp washer 1 - 500 ms
• Power delay to headlamp washer 2 - 100 ms
• Power to headlamp washer 2 - 500 ms
• Delay (soak time) of power supply to the headlight washer 1 - 700 ms
• Power to headlamp washer 1 - 500 ms
• Power delay to headlight washer 2 -100ms
• Power to headlamp washer 2 - 500 ms

If there is less than 1 litre of washer fluid left in the washer fluid reservoir, the CJB temporarily stops the headlamp washers. The fluid level sensor is rigidly connected to the CJB, which also transmits a low fluid level signal to the instrument cluster via the medium speed CAN bus. For more information, refer to the chapter:

• Instrument cluster (413-01 Instrument cluster, Description and operating principle)
• Information and Message Center (413-08 Information and Message Center, Description and Operating Principle)