Ford Kuga

 Service Manual

Speed Control » Speed Control (System Operation and Component Description).
System Operation

Speed Control

Cruise control is integrated into PCM and intervenes in engine management to automatically keep to the target speed selected by the driver.

When the system is active, the vehicle can be accelerated or decelerated without the accelerator pedal being pressed. Cruise control is operated using the control switch units on the steering wheel.

The PCM controls the throttle to achieve this. The ABS module supplies the VSS signal for this.

On vehicles with automatic transmission, the TCM receives a notification via the CAN (controller area network) bus that cruise control is active. The TCM then controls the transmission based on special engine maps.

Cruise control recognizes three operating modes:

• "OFF": Control is switched off.
• "STANDBY": Control is switched on but not active. The speed of the vehicle is not regulated by the cruise control.
• "ACTIVE": Control is switched on and active.

  Cruise control adjusts the vehicle speed to the stored or desired target speed

Every time the engine is started, cruise control is in the "OFF" mode. In this mode, only the "ON" button is operable.

Cruise control is initially set to "STANDBY" mode when the "ON" button is pressed. The green cruise control indicator lamp in the instrument cluster lights up. There is no target speed saved.

Cruise control can only be set to "STANDBY" mode under the following conditions:

• Engine speed is between idle speed and maximum permissible speed.

Cruise control can only be changed into "ACTIVE" mode under the following conditions:

• 2nd - 6th gear engaged
• Engine speed between idle speed and maximum permissible speed
• Vehicle speed at least 40 km/h.

Pressing the "SET+" or "SET-" button activates cruise control ("ACTIVE" mode). The green "Cruise control" indicator lamp in the instrument cluster lights up. The current vehicle speed is saved as the target.

In "ACTIVE" mode the "OFF", "SET+", "SET-" and "RES" buttons are active. If the "RES" button is pressed again, control is suspended. The "RES" button has a dual function and is used to resume and suspend the cruise control.

Tapping the "SET+" button (for less than 640 ms) increases the target speed by 1 km/h at a time.

Holding down the "SET+" button (for longer than 640 ms) increases the target speed until the button is released. If the button is not released, cruise control accelerates the vehicle up to the maximum permissible vehicle speed (200 km/h) or up to the vehicle's maximum speed (whichever speed is lower). Tapping the "SET-" button (for less than 640 ms) reduces the target speed by 1 km/h at a time. When the the "SET-" button is held down, the control reduces the target speed until the button is released. If the "SET-" button is held down until the minimum speed of 40 km/h is reached, cruise control switches to "STANDBY" mode.

Cruise control is put into "STANDBY" mode when the "RES" button is pressed. Control to the stored target speed can be started again by pressing the "RES" button again. If the "SET+" or "SET-" button is pressed while the "RES" function is being performed (control to saved target speed), cruise control saves the current speed as the target speed.

Cruise control goes into STANDBY mode in the following situations:

• Operation of the brake pedal
• Operation of the clutch pedal
• Operation of the parking brake
• If the driver operates the accelerator pedal and the saved target speed is subsequently exceeded for more than 5 minutes.
• Pressing any cruise control button for more than 2 minutes
• Intervention by the traction control or electronic stability program (for longer than 40 ms)
• Shifting of the gear selector lever to the "N" position (vehicles with automatic transmission only)
• Minimum speed falls below 40 km/h.
• Occurrence of particular DTC (diagnostic trouble code)
• faulty signal from the backup lamp switch

Cruise control is switched off when the "OFF" button is pressed.

If the accelerator pedal is pressed down, the vehicle speed increases. As soon as the pedal is released, the speed falls to the saved target value.

The following components supply the signals needed by the cruise control:

The APP sensor.

• The APP sensor identifies the current position of the accelerator pedal and sends a PWM (pulse width modulation) signal to the PCM and an analog DC (direct current) signal to the GEM.
• If one or both of the APP sensors fails, a fault is stored in the PCM fault memory and cruise control cannot be activated.

BPP switch

• The BPP switch tells the PCM whether the vehicle is being braked. In its rest state the switch is closed and sends an earth signal to the GEM. This signal is sent via the CAN to the PCM.
• The brake light switch is likewise connected to the GEM and is opened in the rest state.

  When the vehicle is braked, the brake light switch sends a signal to the GEM. This compares the signals from the BPP switch and the brake light switch. If a discrepancy occurs, a fault is stored in the error memory of the GEM. Cruise control cannot be activated.

CPP switch

• The CPP switch sends a ground signal to the GEM as soon as the clutch is operated. This signal is passed on by the GEM via the CAN bus to the PCM. This then supplies the signal to the cruise control.
• If the CPP switch is incorrectly installed or set, cruise control cannot be activated.

Wheel speed sensors

• The wheel speed sensors record the speed of all the wheels. The recorded speed values are sent to the ABS module via a hard-wired connection. The ABS module calculates a vehicle speed signal (VS signal) from the speed values and the wheel diameter. This vehicle speed signal is transferred via the CAN bus to the PCM and supplied to the cruise control. If the vehicle speed signal is faulty, cruise control cannot be activated.

Parking brake switch

• The parking brake switch is hard-wired to the GEM. The parking brake switch sends a signal to the GEM when the parking brake is operated. The GEM activates the parking brake indicator lamp in the instrument cluster.

  If the parking brake indicator lamp is lit, cruise control cannot be activated.

Back-up light switch

The backup lamp switch is hard-wired to the GEM. The backup lamp switch sends a signal to the GEM when reverse gear is engaged.

The GEM activates the reversing lamp.

Cruise control cannot be activated when reverse gear is engaged.

System Diagram

System Operation

Component Description