Standard Speed Control

The speed control system is integrated with the drive motor management system to automatically maintain a set vehicle speed. Once engaged, the system can also be used to accelerate the vehicle without using the accelerator pedal.

The speed control system comprises the following main components:

• 'SET+' and '-' (SET/increase speed and decrease speed) switches - Located on right steering wheel switchpack
• 'RES' switch - Located on right steering wheel switchpack
• 'Cancel' switch - Located on right steering wheel switchpack
• Clockspring (CLKSPG)
• Speed control warning indicator in Instrument Cluster (IC).

The speed control system uses inputs from the following:

• Brake pedal switch
• Accelerator Pedal Position (APP) sensor
• Powertrain Control Module (PCM)
• Anti-lock Brake System (ABS) control module.

The speed control is operated by the driver using only the speed control switches on the right steering wheel switchpack. When speed control is active, the PCM regulates the output signals received by the Electric Power Inverter Converters (EPICs). Thereby the PCM controls the front and rear Electric Drive Units (EDUs) through their respective front or rear EPIC via the FlexRay bus.

During speed control operation, the PCM controls the vehicle speed by adjusting the phasing of the high voltage Alternating Current (AC) depending on the torque required from the EDU and signals from the 3 integral EDU position sensors. When the accelerator pedal is pressed with speed control active, the APP sensor outputs the signal for the PCM.

The minimum set speed for speed control is 32 km/h (20 mph).

Speed control is automatically suspended if the following conditions apply:

• Vehicle speed falls below 24 km/h (15 mph).
• The brake pedal is pressed.
• The 'Cancel' switch is operated.
• Neutral (N), Park (P) or Reverse (R) gear is selected.
• The Electric Park Brake (EPB) is applied.
• The difference between actual speed and the set speed is too great.
• If the accelerator pedal is used to accelerate beyond the set speed for too long (more than 5 minutes).
• The Anti-Lock Brake System (ABS) control module logs a Diagnostic Trouble Code (DTC) fault.
• System error causes shut-off.
• All surface progress control is selected.

There are 4 standard speed control switches located on the right steering wheel switchpack:

• 'SET+' switch - Increase speed
• '-' switch - Decrease speed
• 'Cancel' switch
• 'RES' switch.

The standard speed control switches are located on the right steering wheel switchpack. The switches are resistive ladder type switches which vary the resistance of a voltage signal sent to them. The right steering wheel switchpack transmits the data to the Body Control Module/Gateway Module (BCM/GWM). The right steering wheel switchpack uses a Local Interconnect Network (LIN) connection to the BCM/GWM. Then the BCM/GWM passes the data onto the Flexray and High Speed (HS) Controller Area Network (CAN) chassis systems buses.