Powertrain Control Module (Pcm)

The cruise control system and the active speed limiter function are managed by the PCM.

The PCM software continually monitors inputs from the SCCM, ABS module, and the TCM module along with numerous input signals. The PCM strategy then provides the appropriate electronic message outputs and hard wired outputs to operate the requested cruise control features.

The PCM monitors all of the cruise control system electrical circuits to determine the system readiness. If the PCM detects a monitored system fault, it sets and stores a Diagnostic Trouble Code (DTC). The PCM uses On-Board Diagnostics (OBD) and can communicate with other electronic modules in the vehicle as well as with the diagnostic scan tool using the CAN network data bus.

Inputs 

• Brake pedal activation from the ABS module
• ESC from the ABS module
• Active Speed Limiter input from the SCCM
• Cruise Control inputs from the SCCM. The PCM monitors the CAN C network every 10ms in order to prevent a missed button press
• VSS signal from the ABS module
• Park brake engagement signal from the ABS module
• Transmission limp mode input from the TCM. ATX only
• Clutch pedal position from the Clutch Position Sensor. Neutral position is detected by lack of correlation between engine and vehicle speed. This is for MTX vehicles only

Outputs 

• Outputs to the IPC for message indication
• TCM to request down/up shifting
• State of the cruise control
• Power, ground, and a dedicated signal line to the Clutch Position Sensor

The PCM can inhibit or disengage cruise control when any of the following occur:

• CSWC button latched or stuck
• Brake pedal position or brake switch rationality errors
• Vehicle speed signal is not available
• TCM is in Limp Mode
• ESC fault detected
• Park brake engagement
• Drivetrain Control Module (DTCM) reports a 4low engagement
• Invalid gear engagement detected
• Clutch switch rationality error
• Engine load sensor error (gas only)
• Fuel injection error
• Turbo sensor or actuator error
• Below minimum speed of 30 Kilometer Per Hour (KM/H) or 18 Miles Per Hour (MPH)
• Engine Revolution Per Minute (RPM) is too high or reported as too high
• Throttle body actuator or sensor errors
• Accelerator Pedal Position Sensor (APPS) errors or errors in the accelerator pedal potentiometer.

The conditions that can turn off ASL are:

• CAN Message failure
• CRC failure
• Cruise Stuck Switch
• Vehicle Speed Signal Failure
• Accelerator Pedal Failure