Ford Workshop Service and Repair Manuals

Headlamps which switch on automatically are fitted in conjunction with a heated windshield and an interior mirror with automatic glare adjustment. The headlamps are switched on automatically as soon as the ambient light around the vehicle is no longer sufficient.

A new light switch is installed for activation of the system. In addition to the standard light switch positions, it also has a position marked AUTO.

A sensor attached to the rear of the interior mirror (light/rain sensor) measures the ambient light conditions around the vehicle.

A module located next to the steering column and behind the dash panel switches the dipped beam headlamps on according to the sensor signal.

Light/rain sensor unit

The light sensor for the automatic headlamps is integrated in a unit with the rain sensor for the automatic windshield wipers. The unit is attached near the interior mirror.

The light sensor consists of the following three main components:

• Close-range light sensor
• Long-range light sensor
• Lens

The close-range light sensor measures the light intensity in the immediate vicinity of the windshield.

The long-range light sensor measures the light intensity directly in front of the vehicle at a greater distance than the close-range light sensor.

If both the close-range light sensor and the long-range light sensor signal a sudden drop in light intensity at the same time, then a processing algorithm in the automatic headlamp module causes the dipped beam headlamps to be switched on.

This algorithm is required to prevent the headlamps from being switched on under certain circumstances.

If for example the vehicle is being driven on a sunny day behind a large lorry which is painted in a dark colour, then both the short-range light sensor and the long-range light sensor will record a low level of light intensity for a long period of time. In this case the sensor must not respond to this continued low level of light.

Automatic headlamp module

The automatic headlamp module is located to the right of the steering column behind the dash panel (LHD vehicles). It is connected to the light/rain sensor via a three-stranded cable.

The data exchange takes place on the CAN bus. The module evaluates the signals from the light sensors and controls the dipped beam headlamps accordingly.

Function

The automatic headlamp function can only be switched on with the ignition lock in position II or III. When the automatic headlamp function is activated, it is only possible to switch on the main beam headlamps if the dipped beam headlamps have been switched on first by the automatic headlamp function.

The headlamp flasher can be switched on at all times regardless of the automatic headlamp function.

If the main beams have been switched on in AUTO mode and the automatic headlamp function then switches the lights off and back on again because of the ambient light conditions, then the main beams are also switched back on again.

If the headlamps are switched off in response to the ambient light conditions, then the system first switches off the dipped beam headlamps, and then after a delay of around 10 seconds the side lights.

The front and rear fog lamps are not controlled by the automatic headlamp module and can only be switched on manually.

Diagnosis

The modular layout allows the light/rain sensor to be replaced separately in the event of a defect. If the dipped beam comes on continuously when the automatic headlamp function is switched on then there is a defect in the sensor. It is not possible to perform a diagnosis of the light/rain sensor itself.

In this case it is still possible to operate the headlamps manually.

If no output signal is delivered from the module then it needs to be replaced. Diagnosis of the module is not possible.

Diagnosis with WDS is not possible.

Part numbers:

• ES-3S7T-17D547-AA (sensor)
• ES-3S7T-17D539-AA (module)

Front fog lamps

The design of the front fog lamps has been modified. A revised installation/removal procedure should now be followed when removing the bulbs. Information on this can be found in the relevant section of the service literature (417-01).

Turn signals

The turn signal lamps have an after-flashing function. When the turn signal switch is pressed and immediately released, the Generic Electronic Module (GEM) initiates three flashes of the turn signal lamps.