This diagnostic test functions on the assumption that a sudden decrease in vehicle speed is caused by a brake pedal application. When the powertrain control module (PCM) detects that there is a 4.2 km/h (2.6 mph) or greater decrease in vehicle speed within 0.25 seconds and a transition of the torque converter clutch (TCC) brake switch without a transition of the stop lamp switch, the PCM sets DTC P1574.
CONDITIONS FOR RUNNING THE DTC
DTCs P0502, P0503, P0719, and P0724 are not set.
The engine speed is greater than 700 RPM.
The traction control system or the antilock brake system are not active and have not failed.
The vehicle speed is greater than 48 km/h (30 mph) in order to enable the diagnostic. The diagnostic will disable when the wheel speed is less than 16 km/h (10 mph).
CONDITIONS FOR SETTING THE DTC
The vehicle speed decreases by at least 4.2 km/h (2.6 mph) within 0.25 seconds.
The PCM detects a TCC brake transition.
The PCM does not detect a stop lamp switch transition.
ACTION TAKEN WHEN THE DTC SETS
The PCM sets the stop lamp switch status to released.
The PCM disables the operation of the cruise control system.
CONDITIONS FOR CLEARING THE DTC
A history DTC will clear after 40 malfunction free warm-up cycles.
The PCM receives a clear code command from the scan tool.
Thursday, March 28th, 2013 AT 10:37 PM