System: Chassis (C-Code)
SAE Standard (Generic)
Family: Brake Booster Pressure Travel Sensor Circuit
Code C056A: Brake Booster Pressure Sensor Power Supply Circuit
Diagnostic & Technical Explanation
Code C056A (Brake Booster Pressure Sensor Power Supply Circuit) sets when the module loses a valid signal from the sensor that reports how far the brake booster's output rod has traveled or how much boosted pressure it has produced -- the circuit is open, its power supply is missing, or the reported value stops tracking pedal input. This sensor lets the module blend booster assist with ABS and stability control pressure requests, so a fault here can cause an inconsistent pedal feel under combined braking events. A damaged sensor element, a corroded connector at the booster body, or a broken 5V supply wire are the usual physical causes.
First-listed procedure
Rank #1
Inspect brake booster pressure/travel sensor connector
Easy DIY
This is the first procedure in the authored
consideration order, not a measured cause likelihood. Execute it only when its prerequisites
and diagnostic findings support it. Its cost and labor estimates (where known), the step-by-step procedure and the
remaining 3 procedure(s) are in the licensed dataset. Ordering context.
Full family: Brake Booster Pressure Travel Sensor Circuit
What this page does not show
This page publishes the fault mechanism and the code index. The licensed dataset adds, for
every one of the 15,886 codes, the full authored repair set (56,729 procedures in total)
with the fields deliberately withheld here:
- Procedures 2..n after the first-listed procedure
- Aftermarket parts cost ranges in USD (
est_parts_cost_min/max_usd)
- Professional labor-hour estimates (
est_labor_hours)
- Step-by-step diagnostic and repair instructions
- Replacement-part mappings and catalog lookups
- 6,637 manufacturer-specific OEM codes across 32 makes ($149 tier)