Dtc C1256-00: Accumulator Low Pressure Abnormality [11/2021 - 03/2024]: Description

WARNING: This page is about a different car, the 2025 Lexus NX 350h, 2024 Lexus NX 350h, 2023 Lexus NX 350h, and 2022 Lexus NX 350h. However, it is still accessible from the selected car via links, so may be relevant.

The Accumulator Pressure Sensor Is Built Into The Brake Booster With Master Cylinder Assembly And Detects The Accumulator Pressure.

The No. 1 Skid Control ECU (Brake Booster With Master Cylinder Assembly) Turns On The Brake System Warning Light (Red Indicator) And Brake System Warning Light (Yellow Indicator), And Sounds The Meter Buzzer If It Senses A Decrease In The Accumulator Pressure.

Dtc C1256-00 May Be Stored If The Accumulator Pressure Drops Due To Frequent Braking (This Is Not A Malfunction).

Dtc No.	Detection Item	Dtc Detection Condition	Trouble Area	Mil	Dtc Output From	Note
C1256-00	Accumulator Low Pressure Abnormality	Significant Drop In Accumulator Pressure Continues. (DTCS Will Be Stored And The Buzzer Will Sound When The Above Condition Is Met.)	Accumulator Pressure Dropped Due To Frequent Brake Pedal Operation (Not A Malfunction) Pump Motor Malfunction Accumulator Deterioration Accumulator Pressure Sensor (Brake Booster With Master Cylinder Assembly) Supply Voltage Reduced Brake Booster With Accumulator Pump Assembly No. 1 Skid Control ECU (Brake Booster With Master Cylinder Assembly)	Does Not Come On	Brake Booster	Output ECU: No. 1 Skid Control ECU (Brake Booster With Master Cylinder Assembly)