System Operation
Non-Adaptive Cruise Control
Item | Description |
---|---|
1 | Brake switch assembly |
2 | IPC |
3 | Accelerator pedal |
4 | Deactivator switch |
5 | Stoplamp switch |
6 | SCCM |
7 | PCM |
8 | Cruise control switches |
9 | GWM |
10 | ABS module |
11 | RCM |
12 | Steering Effort Control Module (SECM) (adaptive steering) |
13 | SASM (adaptive steering) |
Network Message Chart
Network Input Messages - IPC
Broadcast Message | Originating Module | Message Purpose |
---|---|---|
Cruise control override | PCM | Driver overriding cruise control with accelerator pedal. |
Cruise control status | PCM | Data used for speed control indicator status. |
Cruise control set speed | PCM | Data used to display the driver selected vehicle speed |
Network Input Messages - PCM
Broadcast Message | Originating Module | Message Purpose |
---|---|---|
Cruise control switch commands | SCCM | Used for cruise control enable/disable and operating mode request. |
Stability control event in progress | ABS module | Deactivates speed control when requested. |
Traction control event in progress | ||
Vehicle lateral acceleration | RCM | Deactivates speed control when requested. |
Vehicle longitudinal acceleration | ||
Vehicle yaw rate |
Network Input Messages - SCCM (Adaptive Steering)
Broadcast Message | Originating Module | Message Purpose |
---|---|---|
Cruise control switch commands | SASM | Used for cruise control switch enable/disable and operating mode commands on vehicles equipped with adaptive steering. |
Cruise Control Operation
The cruise control functions include:
The cruise control system maintains a selected vehicle speed within a range between 32 km/h (20 mph), or 30 km/h (18 mph) if equipped with a metric cluster, and the maximum limited vehicle speed. When a MyKey® restricted key is in use, the vehicle speed will not exceed the MyKey® maximum limited speed. During normal driving conditions, the vehicle speed can fluctuate slightly from the selected set speed due to road conditions. The vehicle speed can fluctuate more noticably when driving up and down steep hills.
Certain conditions cause the cruise control system to deactivate:
The BPP switch assembly (contains the stoplamp switch and cruise control deactivator switch) and APP sensor are hardwired inputs to the PCM .
Electronic Throttle Body (ETB) command is a hardwired output of the PCM .
The vehicle speed is controlled by the PCM through the Electronic Throttle Control (ETC) subsystem.
The cruise control system provides self-diagnostics. Cruise control is disabled anytime an error is detected in the system. No IPC indicator or message center messages are displayed when faults occur. Fault codes are logged by the PCM , SCCM or SECM (if equipped with Adaptive Steering).
An Electronic Throttle Control (ETC) system fault also causes the cruise control system to be disabled. In this case, an Electronic Throttle Control (ETC) system powertrain malfunction (wrench) warning indicator is displayed.
Cruise Control Indicator
The cruise control indicator, located in the IPC , illuminates to indicate the cruise control system is active.
Steering Wheel Switch Function
Cruise control switch inputs are received by the SCCM and sent to the GWM on the HS-CAN2 and then to the PCM on the HS-CAN1 .
Pressing (ON) and releasing the ON/OFF switch turns the cruise control system on. Pressing (SET+) or (SET-) on the SET switch while the vehicle is traveling at the desired speed activates the cruise control system.
Pressing up or down on the SET switch while in the active mode increases or decreases the maintained vehicle speed by 2 kmh per press when displayed units are "kmh" and 1 mph per press when displayed units are "mph". If the respective switch is pressed and held, the vehicle speed continues to accelerate or decelerate until the switch is released.
Pressing down (OFF) and releasing the ON/OFF switch, or turning the ignition switch to the OFF position, turns the cruise control system off. While the cruise control system is active, applying the brake pedal or pressing the CNCL (CANCEL) switch puts the cruise control system into standby mode. Pressing the RES (RESUME) switch when the cruise control system is in standby mode causes the vehicle to accelerate to the last speed. Resume does not function if the OFF switch is pressed, the ignition switch is cycled OFF, or if the current vehicle speed is below the minimum operational speed.
Steering Wheel Switches
The cruise control steering wheel mounted switches are momentary contact switches that toggle up and down for the switch state. On vehicles without adaptive steering, the switches are an input to the SCCM . On vehicles with adaptive steering, the switches are an input to the SECM . The SECM sends switch data to the SASM (part of the clockspring assembly), and the SASM sends the switch data to the SCCM over the HS-CAN2 .
Brake Switch
When the brake pedal is applied, the cruise control deactivator switch, integrated in the BPP switch, opens and removes the ground signal from the PCM input circuit releasing the throttle, immediately deactivating the cruise control system.