Speed Limiting Description

Engine Controls and Fuel - 5.3L L84 or 6.2L L87 | Description and Operation | Document ID: 4663354 A message will be displayed when the vehicle top speed has been limited to the speed indicated.  The message will no longer display when the speed decreases below 5 kph (3 mph) of the indicated limited speed. The limited speed is a protection for various propulsion and vehicle systems, such as lubrication, thermal, suspension, Teen Driver, or tires. The ECM takes the lowest value from the following list to determine the final vehicle speed limit. The vehicle speed is not limited when the vehicle is in Park or Neutral. Functions that will limit the vehicle speed Tire Rating Prop-shaft/Transfer case speed rating Protection from reduced lubrication Electric motor speed rating Powertrain Thermal Protection Diesel Exhaust Fluid legislated limits Valet or Teen Driver Modes OnStar Stolen Vehicle Feature Commercial Truck / Rental Vehicle Speed Limits Powertrain control system faults Braking system faults Damping system faults Leveling system faults System Components Engine Control Module (ECM) The engine control module monitors the inputs from various modules on the serial data to determine the final top speed limiting value by selecting the lowest requested top speed limit. Body Control Module (BCM) The body control module monitors the top speed limiting requests from serial data communication modules (listed below) along with internally set values (tire, propshaft, valet, and teen limits) to determine the lowest top speed limit and transmits the value to engine control module for final top speed limit determination. Electronic Brake Control Module (EBCM) The electronic brake control module (EBCM) monitors the brake system to determine if a speed limiting signal should be sent to the BCM. Suspension and Damping System The suspension and damping system monitors the active suspension to determine if a speed limiting signal should be sent to the BCM. OnStar Enhanced Services The OnStar Module communicates with OnStar to determine if a speed limiting signal should be sent to the ECM. Automatic Leveling Control The automatic leveling control monitors the leveling system to determine if a speed limiting signal should be sent to the BCM. Integrated Chassis Control Module The integrated chassis control module monitors chassis controls to determine if a speed limiting signal should be sent to the BCM. Rear Driveline Control Module / Transfer Case Control Module The rear driveline control module / transfer case control module monitors the rear driveline or transfer case to determine if a speed limiting signal should be sent to the BCM. Hybrid Module The hybrid module monitors the hybrid system to determine if a speed limiting signal should be sent to the ECM. Transmission Control Module The transmission control module monitors the transmission to determine if a speed limiting signal should be sent to the ECM. Driver Information Center The driver information center alerts the driver when the top vehicle speed is being limited.