P0573

P0573 is the opposite-polarity complaint to P0572: the PCM sees the brake switch A circuit stuck high (open) when it expects the switch to close as the pedal is depressed, so the module never registers a brake application. Cheapest-first ladder: verify the brake lights actually illuminate when the pedal is pressed, because P0573 with no brake-light function points to a failed switch, a blown stop-lamp fuse, or a disconnected switch connector; brake lights work fine but code still sets points to an internal second-pole failure on a dual-contact switch. Measure switch resistance across the PCM-side terminals with the pedal pressed and released. Caveat: do not chase wiring on this code until you have ruled out a faulty switch and verified the pedal bracket is not bent or the floor mat is not holding the pedal slightly off rest position. Replacing a TCM or ABS module on a P0573 is a common shop-level misdiagnosis costing $800 to $1,500 when the actual repair is a $30 switch.

Vehicle-specific patterns: 2014 to 2019 Ram 1500, 2500, and 3500 trucks have a well-known dual-stage brake switch failure where the PCM-side contacts open prematurely; Mopar issued an updated part number and the symptom is often paired with a no-crank because the switch also feeds the starter relay. 2010 to 2015 Chevrolet Camaro and 2008 to 2014 Cadillac CTS set P0573 from the same GM integrated brake switch family as the trucks. 2006 to 2012 Audi A4, A6, and Q7 commonly set P0573 from the F47 brake-pedal switch failing internally. 2003 to 2009 Mercedes E-Class W211 has a documented stop-lamp switch failure that throws P0573 along with limp-home transmission behavior. Estimated repair: $40 to $260.