Published: 11-May-2011
Wipers and Washers - Wipers and Washers - System Operation and
Component Description
Description and Operation
Control Diagram
NOTE: A = Hardwired; N = Medium speed CAN (controller area network) bus; O = LIN (local interconnect network) bus
Item Description 1 Battery 2 EJB (engine junction box) 3 Wiper motor 4 Headlamp washer pump 5 Rain/Light sensor 6 Washer reservoir fluid level switch
7 Windshield washer pump 8 Wiper/Washer switch - RH (right-hand) steering column multifunction switch 9 Instrument cluster 10 CJB (central junction box) 11 BJB (battery junction box)
WINDSHIELD WIPERS System Operation
Operation of the wipers and washers is controlled by the CJB in response to driver inputs from the wiper control switch and signals from the rain/light sensor. The instrument cluster monitors the condition of the wiper/washer control switch and
transmits driver requests to the CJB over the medium speed CAN bus.
The wiper control switch is connected via hardwired connections to the instrument cluster. The instrument cluster outputs on 4
wires a reference voltage to the wash/wipe switch, the auto wiper switch, the wiper switch and the flick wipe switch. All the
switches are connected to the instrument cluster on a common ground. Each switch function is connected to ground via a
resistor or series of resistors and the instrument cluster monitors the ground signal and determines which function has been
selected. The instrument cluster then outputs the appropriate message on the medium speed CAN bus to the CJB which responds to the requested wiper function. The CJB then activates the appropriate function either directly or via relays in the EJB for the wipers and headlamp powerwashers. Speed Dependent Mode
When the wipers are operating, a vehicle speed signal received by the CJB on the high speed CAN bus is used to operate a speed dependent mode. If the wipers are in fast wipe and the vehicle speed decreases to below 2 km/h (1.2 mph), the wipers
will reduce to the normal wipe speed. When the vehicle speed increases to above 8 km/h (5 mph) the fast wiper speed
selection is restored. If slow speed is selected and the vehicle speed drops below 2km/h (1.2 mph), the wipers will operate in
the intermittent mode. When the vehicle speed increases to above 8 km/h (5 mph) the slow wiper speed selection is restored
– this feature is configurable by the dealer using the approved Jaguar diagnostic system.
Wiper Motor
The wiper motor is controlled by the CJB. The CJB is connected to a wiper motor normal/fast relay in the EJB on 2 wires. The CJB is also connected to a wiper run/park relay, also located in the EJB.
Driver requests are received by the CJB which energizes the wiper motor normal/fast relay in the appropriate mode (normal or fast wipe) and also energizes the run/park relay in the run mode by providing a ground for the relay coils. When wiper
operation is deselected by the driver, the CJB monitors a park switch which is integral with the wiper motor. On receipt of a signal from the park switch, the CJB de-energises the run/park relay, removing the power supply through the normal/fast relay, stopping the wipers in the park position on the windshield.
The wiper motor is a DC (direct current) motor which drives a gear wheel via a worm drive attached to the motor spindle. The
motor has 3 sets of brushes with one brush connected to ground. When the normal/fast relay is energized in the normal
position, a power feed is supplied to the brush directly opposite the ground brush and operates the motor at slow speed.
When the relay is energized in the fast position, a power feed is connected to the second motor brush, which is offset from the
ground brush and operates the motor at the fast speed. With power supplied through the offset brush, the current flows
through fewer motor coil windings. This results in a lower resistance to current flow to the ground brush and produces a higher
motor rotational speed.
WINDSHIELD WASHERS
The windshield washers are controlled by the CJB. A driver request for washer operation, via the wiper control switch, is passed to the instrument cluster on the LIN bus. The instrument cluster passes the message to the CJB on the medium speed CAN bus.
The CJB energizes the windshield washer pump during the up stroke of the first 2 wash/wipe cycles. This ensures that wiper fluid is pushed to the sides of the windshield and eliminates the trail of fluid which can occur if the fluid is pushed to the
bottom of the windshield. The wipers will continue for 3 more cycles, followed after a delay of 4 seconds, by a single dry wipe.
NOTE: The dry wipe feature is configurable using an approved Jaguar diagnostic system.
The operation of the washer pump on the wiper up stroke only is configurable using an approved Jaguar diagnostic system.
The washer button can be pressed and held and the wipers will operate continuously for up to 10 seconds. After this period
when the button is released, the wipers will continue for 3 more cycles, followed after a delay, by a single dry wipe. After this
period washing will be inhibited, the wipers will continue for 3 more cycles, followed after a delay, by a single dry wipe.
Reactivating the switch will recommence the wash/wipe cycle.
RESERVOIR LEVEL SWITCH
The level switch is connected directly to the CJB. The switch is operated by a float which closes contacts within the switch when the fluid level falls to below the switch level. When the contacts are closed a ground path is completed from the CJB through the switch. This is sensed by the CJB which issues a message to the instrument cluster which displays a low fluid level warning.
HEADLAMP POWERWASHERS
The headlamp powerwash is activated when the driver requests windshield washer operation. The CJB receives the driver request via a CAN bus message from the instrument cluster. The CJB then checks for an exterior lights active signal and that a low washer fluid level signal is not present.
The CJB outputs a control voltage to a headlamp powerwash pump relay located in the EJB. The relay is energized by the CJB for a pre-determined period to allow the headlamp telescopic washers to operate.
The CJB monitors the driver washer requests and only operates the headlamp powerwash on every fourth request for windshield washer operation, provided that 10 minutes have elapsed since the last headlamp powerwash operation. The
powerwash sequence is reset when the headlamps or the ignition is switched off.
NOTE: If a low fluid reservoir level is present the CJB prohibits headlamp powerwash.
RAIN/LIGHT SENSOR
On receiving a request for automatic windshield wiper operation, the CJB interprets LIN bus messages received from the rain sensor. The rain sensor provides LIN bus messages with values ranging from 0 to 7.
A signal value of 0 is interpreted by the CJB as the windshield is dry. A signal value from 1 to 5 is interpreted by the CJB as a small amount of water hitting the windshield. In this instance, the CJB initiates a slow wipe. A signal value of 7 is interpreted by the CJB as a large amount of water hitting the windshield. In this instance, the CJB initiates a fast wipe. NOTES:
The CJB will only change a fast wipe routine to a slow wipe routine if the rain sensor value is lower than 7.
A = Clean and dry windshield; B = Wet and dirty windshield
Item Description 1 Windshield outer surface 2 Optical element 3 Transmitter diodes (100% light transmitted) 4 Rain sensor
On vehicles with headlamp powerwash, each headlamp assembly is fitted with a headlamp powerwasher. The powerwasher is
located on the underside of the headlamp assembly. The powerwasher is located in a clip at the front of the headlamp and
secured with 2 self tapping screws to the headlamp body.
The powerwasher is a telescopic unit which extends forwards from the headlamp assembly under washer fluid pressure
supplied by the headlamp powerwash pump. When the pump pressure decreases the powerwasher is automatically retracted
back into the housing. The outer end of the powerwasher is fitted with a trim which blends the powerwasher into the headlamp
when it is not operating. The powerwasher has two washer jets which direct washer fluid under high pressure onto the
headlamp lens when the powerwasher is extended.
RAIN/LIGHT SENSOR
The rain/light sensor is located at the upper edge of the windshield, behind the interior rear view mirror. Contact between the
rain sensor and windscreen is provided via a silicon pad which is compressed during the assembly process by two locking
retaining clips either side of the sensor.
The rain/light sensor unit attaches to the windshield via two clips, which latch onto formed tags on the windshield bracket.
The sensor provides information to the CJB for the optimum wiper operation for the prevailing conditions to maintain the shield in a clear condition at all times. The rain/light sensor is an optical unit, which operates on an infrared waveband. The sensor
uses the principle of the laws of reflection on interfacing surfaces between materials with differing refraction properties.
The rain/light sensor is connected to the CJB via a LIN bus. The sensor also receives a hardwired power and ground from the CJB. The 'auto' wipers are activated when the column stalk is moved to position 1 (first position from off in the upward direction). The sensitivity of the sensor can be adjusted by rotating the sensitivity collar on the wiper column stalk in the
clockwise or counterclockwise direction. Clockwise rotation will decrease sensitivity, while counterclockwise adjustment will
increase sensitivity. An increase in sensitivity adjustment results in a single wipe of the front wiper motor.
NOTE: The rain sensor also contains a light sensor. The light sensor is used to control operation of the automatic
headlamps function.
Refer to: Exterior Lighting (417-01 Exterior Lighting, Description and Operation).
WIPER CONTROL SWITCH
The wiper control switch is located on the RH steering column multifunction switch. The switch allows selection of the following functions:
Slow wipe
Fast wipe
Auto
Flick wipe
Windshield wash and headlamp powerwash (if fitted).
All wiper functions are connected to the instrument cluster by a resistor or series of resistors within the switch. The instrument
cluster uses the returned current to determine the selected function.
WIPER SERVICE POSITION
The wiper service position allows the wipers to be parked in a position to allow easy access to the wiper blades for
replacement. The service position is initiated by pulling the RH steering column multifunction switch towards the steering wheel and pressing the start/stop button to switch on the ignition. The wipers will move and stop in a vertical position on the
windshield. The RH steering column multifunction switch can be released and the ignition switched off. The service position is terminated at the next ignition on cycle and the wipers return to their normal park position.
- Disadvantage: Scarring and hardening of the surface.
Flattening using a copper electrode.
- Small, sharp dents that face outwards can be worked on with a copper electrode.
Flattening using a flame and body files.
NOTE: When applied correctly, this method can be used with all the attached parts still in place (roof headlining,
wiring harnesses etc.).
- Small, soft dents (only slight stretching): Working at the edges of the dent in an inward spiral pattern, the dent
is heated with an oxyacetylene torch (torch size 1 - 2 mm, excess gas flame) to approx. 250° C.
- Working rapidly with a body file extracts heat from the edge area until the dent is flattened. Preferably alternate
between two files. This increases the amount of heat that can be extracted.
Safety measures
The electronic control modules (ECM) fitted to vehicles make it advisable to follow suitable precautions prior to carrying
out welding repair operations. Harsh conditions of heat and vibration may be generated during these operations which
could cause damage to the modules. In particular, it is essential to follow the appropriate precautions when
disconnecting or removing the airbag RCM.
Do not allow electronic modules or lines to come into contact with the ground connection or the welding electrode.
Seat belt anchorages are a safety critical. When making repairs in these areas, it is essential to follow design
specifications. Note that extra strength low alloy steel may be used for seat belt anchorages. Where possible, the
original production assembly should be used, complete with its seat belt anchorages, or the cut line should be so
arranged that the original seat belt anchorage is not disturbed.
All welds within 250mm (9.842) of seat belt anchorages must be carefully checked for weld quality, including spacing of
spot welds.
Remove the battery before carrying out welding work in its vicinity.
Utmost care must be taken when welding near the fuel tank or other components that contain fuel. If the tank filler
neck or a fuel line must be detached to allow access for welding work, then the fuel tank must be drained and removed.
Never weld, on components of a filled air conditioning system. The same applies if there is a risk of the air conditioning
system heating up.
Connect the ground connection of the electrical welder directly to the part that is to be welded. Make sure that there
are no electrically insulating parts between the ground connection and the welding point.
Adjacent vehicle parts and adjacent vehicles must be shielded against flying sparks and heat.
Pedestrian protection system
The pedestrian protection system is designed to mitigate injuries in a pedestrian collision with the vehicle. It does this by
utilizing a pair of pyrotechnic actuators to lift the hood away from the engine, creating a cushioned impact between the
pedestrian and the vehicle. It is essential that any repair or replacement operations do not affect the safe working of the
system.
For additional information, refer to: Pedestrian Protection System (501-20C Pedestrian Protection System, Description and Operation).
Resistance spot welding
Where resistance spot welds have been used in production, they must be reproduced with new spot welds in replacement
where possible. All such reproduction spot welds should be spaced 25 to 30mm apart.
Setting up the equipment and co-ordinating the welding parameters.
Equipment:
- Follow the equipment manufacturer's instructions for the equipment settings.
- Select the correct electrode arms (as short as possible).
- Align the electrode arms and tips exactly.
- Electrode tips should be convex (rough shaping with a file, fine shaping with a sanding block).
Body:
- Make sure that the flanges to be joined lie perfectly flat to one another.
- Prepare a bare metal joint surface (inside and outside).
Notes on technique/method:
- Carry out a test weld on a sample piece of the material coated in welding paste.
- If any metal parts are located between the electrode arms then there will be a loss of induction and therefore
power (adjust current setting).
- The power needs to be adjusted for high-strength low alloy steel.
- Repeated welding on old welding points often leads to poor quality welds.
- Keep the electrode tips as near as possible to an angle of 90° to the contact surface.
- Keep the pressure on the electrodes for a short period after finishing the weld.
- The electrodes work best if their shape is convex. Clean the contact surface of the electrodes regularly.
Resistance spot welding panels where the total thickness is 3 mm or more
For all repairs to modern Jaguar vehicles, spot-welding equipment should be suitable for reliable welding of zinc-plated,
high-strength and high-tensile steels in three or more layers, up to 5 mm total thickness. If these requirements are not
fulfilled, plug welding must be used for safety reasons. The electrical specifications (current, resistance, heat) of the
spot-welding equipment have different validity, depending upon the type of equipment. Therefore, it is essential that the
manufacturer's instructions are observed with regard to the actual welding performance.
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(100-00 General Information, Description and Operation) /
Body Repairs (501-25A Body Repairs - General Information, Description and Operation) /
Corrosion Protection (501-25B Body Repairs - Corrosion Protection, Description and Operation) /
Body and Frame (501-26 Body Repairs - Vehicle Specific Information and Tolerance Checks, Description and Operation).
4. Disconnect the battery ground cable.
For additional information, refer to: Battery Disconnect and Connect (414-01 Battery, Mounting and Cables, General Procedures).
5. Remove the front bumper cover.
For additional information, refer to: Front Bumper Cover (501-19 Bumpers, Removal and Installation).
6. Remove the fender splash shield.
For additional information, refer to: Fender Splash Shield (501-02 Front End Body Panels, Removal and Installation).
7. If the right-hand front fender is to be repaired, remove the windshield
washer reservoir.
For additional information, refer to: Windshield Washer Reservoir (501-16 Wipers and Washers, Removal and Installation).
8. Remove the headlamp assembly.
For additional information, refer to: Headlamp Assembly (417-01 Exterior Lighting, Removal and Installation).
9. Remove the rocker panel outer moulding.
10. Remove the front fender.