Diagnostic Aids
WARNING: This page is about a different car, the 2002 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.
DTC P1574 indicates the brakelight switch signal to the EBCM or the EBCM's ability to send the brakelight switch signal to the PCM has failed. Refer to ABS/TCS DTCs for diagnosis of the brakelight switch signal and the EBCM.