Chassis, generic

C056D Brake Pedal Position Sensor Supply Voltage Circuit Low

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

The brake pedal angle sensor of a hybrid or brake-by-wire car is fed from a regulated 5 V line. C056D means this supply is present but sagging. Ford's 2015–2019 hybrid summaries set a joint window for C056D and C056E: if the supply leaves 4.87–5.13 V for 50 ms, the code for the low or high side is stored; in Ford's ABS module both appear as C100F and the hybrid powertrain module shows C056D for the low case. A drooping reference usually means a short to ground inside the sensor, a damaged supply wire or another load on the same rail. GM uses C056D in its own way, for example with parking brake faults on 2017–2019 Acadia, Traverse, Enclave and XT5 (PIT5662A).

Likely causes

Pedal sensor loading the supply through an internal fault
Supply wire chafed to ground near the pedal box
Another sensor on the same 5 V rail pulling it down
Weak 5 V regulator in the brake module

Symptoms

  • Brake system warning and possibly stability lamp
  • Regenerative braking reduced, firmer friction braking
  • On GM models parking brake messages instead

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€40–450
Time0.5–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

brake pedal position sensorsensor supply

Related codes

C056EC0562P057BP057E

References: fordservicecontent.com, bosch-mobility.com, eenewseurope.com, static.nhtsa.gov.