Abstract: A transportation vehicle provides a brake autohold function to maintain braking without requiring the driver to continuously apply pressure on a brake pedal. The vehicle comprises an autohold selector, a parking brake selector, a brake pedal, and an accelerator pedal. A braking system is adapted to enter an autohold event according to a pressed brake pedal at vehicle standstill during an active autohold mode toggled by the autohold selector. A controller is configured to terminate the autohold event in response to either a deactivation command using the parking brake selector or accelerator pedal movement, without deactivating the autohold mode. By manually terminating the brake autohold event the vehicle can begin to creep forward using only the torque generated by the engine at idle, thereby avoiding the additional torque that is generated when the accelerator pedal is used to terminate the brake autohold event.

Abstract: A transportation vehicle provides a brake autohold function to maintain braking without requiring the driver to continuously apply pressure on a brake pedal. The vehicle comprises an autohold selector, a parking brake selector, a brake pedal, and an accelerator pedal. A braking system is adapted to enter an autohold event according to a pressed brake pedal at vehicle standstill during an active autohold mode toggled by the autohold selector. A controller is configured to terminate the autohold event in response to either a deactivation command using the parking brake selector or accelerator pedal movement, without deactivating the autohold mode. By manually terminating the brake autohold event the vehicle can begin to creep forward using only the torque generated by the engine at idle, thereby avoiding the additional torque that is generated when the accelerator pedal is used to terminate the brake autohold event.

Abstract: An on-board diagnostic system of a vehicle comprises disabling diagnostic operation, such as a misfire monitor, based on road roughness. In one example, the disabling of the diagnostic operation is based on brake actuation and degradation of an anti-lock braking system.

Abstract: An on-board diagnostic system of a vehicle comprises a diagnostic component configured to detect a vehicle operating condition and to produce an error output when the vehicle operating condition is determined to be abnormal; and a rough road detector configured to determine an average level of roughness of a road surface based on signals from wheel speed sensors, to compare the roughness with a predetermined threshold, and to disable the error output of the diagnostic component or switch to an alternate calibration for the diagnostic component if the roughness level has exceeded the predetermined threshold.