Windscreen Wipers Not Operating As Expected When In Auto (SSM51297)

WINDSCREEN WIPERS NOT OPERATING AS EXPECTED WHEN IN AUTO

TECHNICAL SERVICE BULLETIN

CONCERN

Windscreen wipers are not operating as expected when windscreen wiper switch is set to AUTO. This has led to a significant number of rain sensor replacements which have been deemed "No Fault Found" when returned to the supplier.

CAUSE

Any one or a combination of the following could lead to unexpected operation:-

• The rain sensor detection area is dirty, contaminated or otherwise obstructed
• The rain sensor or sensor bracket isn't fitted correctly
• The windscreen is damaged in the rain sensor detection area

ACTION

Verify the customer concern using the following procedure:-

Ensure the windscreen wiper switch is in the AUTO position; turn the ignition on, then using a small hand dispenser, spray water onto the sensor detection area. If an issue is confirmed, conduct the following functional check before considering replacement of the rain/light sensor:-

Check normal operation of the headlights. If the headlights operate correctly, turn the headlight switch to the AUTO position, turn the ignition on, cover the rain/light sensor with your hand and visually check if the headlights illuminate as expected.

XF ONLY: Ensure the solar sensor (located on the top of the facia) is also covered during the test; failure to do so will invalidate the result.

If the headlights fail to operate as expected further electrical diagnosis will be required including sensor replacement if necessary.

If the auto headlight function does operate as expected complete the following checks:-

Screen area over sensor not being wiped/cleaned effectively

• Ensure the windscreen wiper blades are in good condition
• Ensure that the wiper arms are correctly aligned to the spindles.
• Ensure the specified windscreen washer fluid is being used, and that the mix ratio is correct

Sensor quality/build concerns

• Ensure that there are no visible bubbles between the rain sensor and the windscreen.
• Ensure that the rain sensor bracket is correctly attached to the glass.
• Ensure that the rain sensor is correctly clipped to the bracket.

Damage

• Check the general condition of windscreen within rain sensor detection area (cracks, damage etc).

If all the above checks have been completed and no faults are found:-

Remove the rain sensor; clean the pad and windscreen within the sensor detection area.

Refit the rain sensor onto the bracket ensuring it is correctly secured

FINAL TEST: Ensure that the windscreen wiper switch are set to AUTO position, turn the ignition on then using a small hand dispenser, spray water onto the sensor detection area. If the system still doesn't operate as expected, replace the rain/light sensor.